c-spine

Which of the following is the best explanation for why the lateral cervical spine projection needs to be performed with a 72-inch SID?1. It reduces magnification of the cervical spine
2. It prevents size distortion of the cervical vertebrae
3. It results in better spatial resolution of the cervical vertebrae
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Which of the following is the best explanation for why the lateral cervical spine projection needs to be performed with a 72-inch SID?1. It reduces magnification of the cervical spine
2. It prevents size distortion of the cervical vertebrae
3. It results in better spatial resolution of the cervical vertebrae
1, 2, and 3
In the lateral position, the patient's shoulders displace the spine away from the image receptor (IR) resulting in a large object-to-image receptor distance (OID). When there is a large OID, the resulting image will display size distortion in the form of magnification and this will result in reduced spatial resolution. To compensate for the large OID, SID must be increased to minimize size distortion and improve spatial resolution.
When performing an AP projection of the cervical spine to demonstrate the most superior two Vertebrae, which of the following planes or lines should be perpendicular to the image receptor (IR)?
Occlusal plane
When performing a localized AP projection of the upper cervical spine, the base of the skull should superimpose the inferior margin of the top teeth. This will demonstrate the maximal anatomy of the dens as well as the lateral masses of C1 and the C1/C2 articulation.
When evaluating an image of the first and second cervical vertebrae, the technologist notices that the front teeth are directly superimposing the base of the skull. What, if any, correction should be made?
This is correct, no correction is needed.
If the teeth and base of the skull are perfectly superimposed the image cannot be improved upon, even if there is superimposition of the odontoid process. If the teeth are demonstrated over the tip of the odontoid, then the chin needs to be lifted to tilt the head up more and superimpose the lower margin of the upper incisors over the base of the skull. If the base of the skull is projected over the odontoid, then the head needs to be lowered more. Opening the mouth more would not fix the problem since only the lower jaw moves to open the mouth, leaving the upper teeth still in the wrong location.
When performing an AP axial projection of the cervical spine, in order for the central ray to pass through C4, what is the appropriate entrance point for the beam?
Inferior margin of the thyroid cartilage.
When performing an AP axial projection of the cervical spine, the central ray should be angled 15-20 degrees cephalad. Because the central ray should pass through C4, and because there is a cephalic angulation of the beam, the central ray should enter inferior to the level where it exits. In this case, for the central ray to pass through C4, it will need to enter the anterior neck at the inferior margin of the thyroid cartilage.
When performing an RPO cervical spine projection, how much should the patient be rotated, and which structures will be demonstrated?
45 degree patient rotation demonstrates elevated intervertebral foramina
The intervertebral foramina of the cervical spine open anteriorly at an angle 45 degrees from the midsagittal plane; they are directed inferiorly approximately 15-20 degrees. Posterior oblique cervical spine images (RPO, LPO) are performed with the patient rotated 45 degrees from the AP position. This positioning will demonstrate the elevated intervertebral foramina.
When performing an RAO projection of the cervical spine, how should the central ray be positioned?
15 degree caudal angle.
The intervertebral foramina of the cervical spine open anteriorly at an angle 45 degrees from the midsagittal plane; they are directed inferiorly approximately 15-20 degrees. In order for the central ray to pass through the intervertebral foramina, the central ray should be directed 15 degrees caudad when performing PA obliques and 15 degrees cephalad when performing AP obliques.
In order to demonstrate the left intervertebral foramina of the cervical spine with the least amount of size distortion, which projection should be obtained?
Left anterior oblique
The intervertebral foramina of the cervical spine open anteriorly at an angle 45 degrees from the midsagittal plane; they are directed inferiorly approximately 15-20 degrees. Although not all protocol manuals use this method, to demonstrate the intervertebral foramina with minimal size distortion (magnification) the patient should be adjusted into the left anterior oblique position, putting the side of interest closest to the image receptor.
Which of the following statements is true for both oblique and lateral projections of the cervical spine?
A 72 inch SID should be used when erect images are obtained
In order to compensate for the increased distance between the spine and the IR when performing oblique and lateral cervical spine images, the central ray should be adjusted to take advantage of the greatest SID. When positioning for a lateral image, the MSP of the head is parallel with the image receptor and the chin is slightly elevated to prevent superimposition of the mandible and the spine; because the patient's entire body is rotated 45 degrees for an oblique image, there will always be superimposition of the spine and mandible. The beam is perpendicular for a lateral image and angled 15-20 degrees for an oblique image.
Which of the following represent structures demonstrated on a correctly positioned lateral cervical spine exam?
1. Vertebral bodies and spinous processes in profile
2. Pedicles of elevated side
3. Transverse processes in profile
1 only.
On the lateral projection, the bodies and spinous processes should be in profile with no rotation. The disc spaces will also be well demonstrated between the bodies. The transverse processes are not well visualized on the lateral, and the pedicles and intervertebral foramina are visualized only on oblique projections.
For AP projections of the cervical spine, which of the following statements is TRUE regarding centering of the x-ray beam to the part?
The patient's midsagittal plane (MSP) should be centered to the middle of the (IR).
The MSP divides the body into equal right and left halves; placing this plane in the center of the receptor will ensure that the spine is in the middle of the x-ray field and IR. For an AP projection, the top of the light field or 10x12 inch IR should lay at the top of the ears and the central ray should enter the patient at the inferior thyroid cartilage and exit at the level of C4.
Which projection of the cervical spine would best demonstrate a Jefferson fracture?AP open mouth for C1/C2. A Jefferson fracture is a "burst" type fracture of the atlas (C1). It is best demonstrated on the AP open mouth projection of C1 and C2 as bilateral spreading or offset position of the lateral masses of C1 compared to the odontoid or lateral edges of C2.The "vertebra prominens" is a common name for which cervical vertebra?C7 The term "vertebra prominens" may be used to identify C7 because of the very large and prominent spinous process. This is an easily palpated positioning landmark.What projection of the cervical spine would best demonstrate the atlantoaxial joint?AP open mouth for C1/C2. The superior and inferior articular processes of the cervical vertebrae are oriented 90 degrees from the midsagittal plane. To demonstrate the atlantoaxial joint, the AP open mouth image of C1 and C2 is the best option. For the rest of the cervical spine the lateral image is used to demonstrate zygapophyseal joints.Which of the following statements is/are TRUE of the cervical vertebrae? 1. C5 has a bifid spinous process 2. C1 is composed of a body, lateral masses, and a posterior arch 3. There are three foramina in each of the cervical vertebrae1 and 3 Unique characteristics of the cervical spine include bifid spinous processes (C3-C6) and in addition to the vertebral foramen, there are transverse foramina in the transverse processes of each. Embryologically, the dens is considered to be the body of C1 however it fuses to C2 during in utero development.The typical zygapophyseal joints of the cervical spine are classified as which of the following?Diarthrodial, plane The typical cervical zygapophyseal joints are diarthrodial (freely movable), plane or gliding joints. The atlanto-occipital joint between the skull and C1 is a diarthrodial ellipsoid (condyloid) type joint and the atlantoaxial joint (between C1 and C2) is a diarthrodial trochoid/pivot type joint.