Spine

Which of the following represents correct evaluation criteria for an AP lumbosacral spine radiograph? 1. The pedicles are equidistant to the spinous processes 2. Spinous processes are centered to the vertebral bodies 3. The vertebral laminae are superimposed

1 and 2 When evaluating an AP lumbar spine radiograph, rotation can be determined by the appearance of the spinous processes and the pedicles. The spinous processes should be centered to the vertebral bodies and the pedicles should be equidistant to the spinous processes. When the knees are bent, the spine will be parallel to the image receptor and the intervertebral joint spaces clearly seen.

In order to minimize distortion of the sacrum in frontal projections, which of the following is the most correct angulation of the central ray?

15 degrees cephalad The sacrum exhibits a concave anterior surface and a convex posterior surface in normal adults. Females typically have a slightly more pronounced curvature. In order to demonstrate this bone with minimal shape distortion, the central ray should be directed to be perpendicular to the anterior surface of the bone. In the average adult, a 15 degree cephalad angulation of the central ray will be perpendicular to the body of the sacrum.

A patient presents in the Emergency Department with severe pain in the inferior spine after falling on the ice. A coccyx examination is ordered. When performing the lateral projection of the series, what is the appropriate central ray entrance point?

3.5 inches posterior and 2 inches inferior to the ASIS In order for the central ray to pass through the coccyx, it should enter the body more inferiorly than for sacral or combined sacral/coccygeal images. For dedicated lateral coccyx images, the central ray enters the body 3-4 inches posterior to the ASIS and approximately 2 inches inferior to the level of the ASIS.

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 a right posterior oblique (RPO) lumbar spine radiograph, the body should be rotated so that the mid-sagittal plane (MSP) forms what degree of angulation with the image receptor (IR)?

45 degrees Oblique lumbar spine images are typically obtained in order to evaluate the zygapophyseal joints. These joints are oriented at a 45 degree angle to the MSP. Optimal positioning is demonstrated when the vertebrae have the appearance of a "scotty dog".

In an infant, the sacrum is normally composed of how many segments?

5 At birth, the sacrum is normally composed of 5 segments of bone which usually fuse into a single bone by adulthood. The coccyx is composed of 3-5 segments at birth which fuse into a single bone by adulthood.

Which letter on the image below is pointing to the superior articular process?

A A refers to the superimposed superior articular processes; B is the median sacral crest; C is pointing to the greater sciatic notch; D is pointing to the intervertebral foramina of L4; and E is pointing to the sacral promontory.

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.

A patient is positioned for a lateral cervicothoracic, Swimmers, projection of the spine. She is able to adequately separate the shoulders to avoid superimposition. What is the central ray entrance point, and the degree and direction of central ray angulation?

Central ray enters C 7, beam perpendicular The lateral cervicothoracic, or Swimmers, projection of the spine is performed to demonstrate the lower cervical and upper thoracic spine because normal lateral cervical and thoracic spine radiographs commonly superimpose the shoulders over this region. This projection separates the shoulders so that C6-T2 can be visualized with minimal superimposition. If the patient can easily separate the shoulders, the central ray should be perpendicular and pass through C7. When the shoulders are not adequately separated, the central ray should still pass through C7, but may be angled slightly (3-5 degrees) caudally.

The primary reason for having the supine patient flex the knees for an AP thoracic spine projection is to:

Decrease OID by reducing the curvature of the lower thoracic and upper lumbar spine Having the patient flex the knees while in a supine position decreases the curvature of the lower thoracic and upper lumbar spine placing the entire spine more parallel and closer to the image receptor.

On this image of the lumbar spine, letter A refers to the:

Intervertebral foramen Letter A is pointing to the intervertebral foramen between L2 and L3. Intervertebral foramina are formed by the inferior pedicle borders of one vertebra and the superior borders of the pedicle of the vertebra below. These openings permit transmission of spinal nerves and vascular structures.

Which of the following projections would best demonstrate the extent of disease in a patient with kyphosis?

Lateral thoracic spine Kyphosis is an abnormal increase in the anterior concavity, or anteroposterior curvature of the thoracic spine. Measurements to determine the degree of curvature can be made on lateral images of the thoracic spine.

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 regarding positioning for a lateral lumbar spine?

The central ray enters at the midcoronal plane Correct centering for a lateral lumbosacral spine should demonstrate the central ray entering the midcoronal plane at the level of the iliac crest. If the lateral is for demonstration of the lumbar spine only, the central ray will enter the midcoronal plane approximately 1.5 inches superior to the level of the iliac crests.

When evaluating an AP projection of the thoracic spine the technologist notices that the sternal extremity of the left clavicle superimposes the body of T3 and the sternal extremity of the right the clavicle superimposes the right lung apex. Which of the following statements are true about this radiograph?The patient was rotated into a slight RPO position

The patient was rotated into a slight RPO position Correct positioning of an AP projection of the thoracic spine should demonstrate the sternal extremities of the clavicles in the same horizontal plane and equidistant to the spinous process of the 3rd thoracic vertebra. This scenario demonstrates the radiographic appearance of a patient who is rotated toward the right side, into a shallow RPO.

Which of the following statements correctly describes the zygapophyseal joints of the thoracic spine?

They are oriented in a plane 20 degrees from the midcoronal plane (MCP) The zygapophyseal joints of the thoracic spine open anteriorly at an angle 70 degrees from the MSP or 20 degrees from the MCP. These joints are best demonstrated on oblique images of the thoracic spine.

Which of the following structures is/are part of the sacrum? 1. Promontory 2. Transverse foramina 3. Auricular surface

1 and 3 The promontory of the sacrum is the prominent ridge on the anterior surface of the first sacral segment. The auricular surfaces are on the lateral sacrum where it articulates with the hip (innominate) bones. Transverse foramina are only found in the cervical region of the spine and allow for transmission of the vertebral arteries.

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

When performing a lateral lumbar spine on a patient with a wide pelvis and a narrow waist, which of the following should be done?

A sponge should be placed under the waist to ensure the entire spine is parallel to the image receptor When patients have wide hips and narrow waists the lumbar spine tends to sag at the waist, resulting in shape distortion of the vertebrae. In order to prevent this sagging and to place the spine parallel with the image receptor, a sponge should be placed under the patient's waist.

Which of the following structures is shown on an AP projection of the thoracic spine? 1. Zygapophyseal joints 2. Intervertebral disk spaces 3. Thoracic transverse processes

2 and 3 A properly positioned AP thoracic spine radiograph will demonstrate the vertebral bodies and intervertebral disk spaces, the transverse processes of the thoracic vertebrae and the costovertebral joints. The zygapophyseal joints are demonstrated on oblique images of the T-spine

Which of the following would be benefits of flexing the knees when performing an AP lumbosacral spine x-ray? 1. Flexing the knees straightens the curve of the spine and places it closer to the image receptor (IR) 2. Flexing the knees results in more consistent brightness levels across the length of the spine 3. Flexing the knees makes the patient more comfortable reducing the chance of motion

1 and 3 The lumbar spine has a natural convex curve, which can cause shape distortion of the vertebrae. Bending the knees straightens this curve bringing the spine more parallel with the IR, and also places the spine closer to the image receptor, reducing magnification that might occur due to the distance between the spine and the receptor. This position is also more comfortable for the patient, so it is easier to maintain and there is a reduced chance of motion.

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 vertebrae

1 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.

Which of the following is/are appropriate evaluation criteria for an AP projection of the sacrum? 1. Sacrum free of superimposition by the pubic symphysis 2. Open L5/S1 joint space 3. Superimposition of the sciatic notches

1 only When properly performed, an AP radiograph of the sacrum will demonstrate the bone free of superimposition by the pubic symphysis. The sacroiliac (SI) joints should be visualized and appear symmetrical to indicate that the patient was in a true AP position with no rotation. With the correct angulation of the x-ray beam, the sacral foramina should be open and well-demonstrated. The sciatic notches are superimposed on the lateral projection.

For the lateral projection of the L5-S1 joint, the central ray is directed:1 to 1 ½ inches inferior to the iliac crest and 2 inches posterior to the ASIS

1 to 1 ½ inches inferior to the iliac crest and 2 inches posterior to the ASIS The joint space between the 5th lumbar vertebra and the sacrum is a common site for pathology, especially spondylolisthesis. This is a condition where one vertebra slips anteriorly in relation to the vertebral body below. To properly demonstrate the L5/S1 joint space, the central ray should enter the patient approximately 2 inches posterior to the ASIS and 1 ½ inches inferior to the iliac crest.

Which of the following reflect correct positioning guidelines for performing a lateral thoracic spine radiograph with the patient in a recumbent position? 1. Shoulders superimposed and hips superimposed 2. Arms forward and positioned perpendicular to the body with elbows flexed 3. Hips and knees flexed

1, 2, and 3 For a lateral image of the thoracic spine, the entire body should be positioned in a true lateral position; shoulders should be directly superimposed and hips should be superimposed. The arms should be positioned anterior and perpendicular to the body to elevate the ribs and better demonstrate the intervertebral foramina. The hips and knees are flexed to provide stability and reduce the chance of voluntary motion.

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 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.

Which of the following is/are appropriate evaluation criteria for a lateral projection of the sacrum? 1. Symmetrical sacral foramina 2. Greater sciatic notches are superimposed 3. Superimposition of the femoral heads

2 and 3 When the patient is properly positioned for a lateral sacrum image, the bone should be demonstrated in lateral profile and the hip bones and femurs should be directly superimposed. This can easily be evaluated by examining the greater sciatic notches and the posterior borders of the ischial bones. Sacral foramina are visible on AP axial images of the sacrum rather than on the lateral.

Where should the central ray enter for a right posterior oblique (RPO) of the lumbosacral spine?

2 inches medial to the left ASIS at the level of the iliac crest Centering at the iliac crest ensures the entire lumbosacral spine is included on the radiograph. In order for the central ray to pass through the spine, the central ray should enter approximately 2 inches medial to the elevated (left) ASIS.

When performing an AP axial projection of the sacrum, the central enters at the midsagittal plane (MSP) and:

2 inches superior to the pubic symphysis The sacrum forms the posterior portion of the pelvic girdle, and lies between the two hip (innominate) bones. When the central ray is angled to demonstrate a non-distorted image of the sacrum the central ray should enter the MSP at a point approximately 2 inches superior to the pubic symphysis and pass through the body of the sacrum.

What is the correct central ray orientation for a localized lateral of the L5/S1 vertebrae?

5-8 degrees caudad Most patients are built so that the hips are wider than the shoulders, so angling the central ray 5-8 degrees caudad compensates for the natural angle created by the width of a patient's hips. Five degrees is typically recommended for a male patient, and eight degrees is recommended for a female patient. The angle may vary depending on the width of the patient's hips and the angle at the L5-S1 joint.

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 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.

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.

The outer portion of an intervertebral disk the:

Annulus fibrosus Vertebral bodies are separated from each other by intervertebral disks. The central portion of each disk, or nucleus pulposus, is soft and spongy. The outer portion of each disk is denser, composed of fibrocartilage and is referred to as the annulus fibrosus.

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.

What is the classification of a costovertebral joint?

Diarthroidial, gliding The costovertebral articulations between the ribs and thoracic vertebrae must be freely movable to allow the thoracic cavity to expand and contract with respiratory motion. These joints are classified as diarthroidial, gliding joints.

Which letter on the image below is pointing to the sacral promontory?

E The promontory of the sacrum is the prominent ridge on the anterior surface of the first sacral segment and is identified by the letter E. A refers to the superimposed superior articular processes; B is the median sacral crest; C is pointing to the greater sciatic notch.

What is the purpose for placing a sponge under the patient's waist when obtaining a lateral thoracic spine image?

Ensures the spine is parallel with the image receptor When performing a lateral thoracic spine radiograph, the spine should be positioned so that it is parallel with the image receptor. To facilitate that, the patient should be given a pillow for the head to rest on and a sponge or support may be placed under the waist.

To reduce air volume and create a uniform brightness on an AP radiograph of the thoracic spine, which of the following is the most appropriate breathing instruction?

Expose at the end of expiration When the exposure is made at the end of expiration, the volume of air in the thorax is decreased and there is a more even appearance to the spinal structures.

What is the appropriate central ray angulation and entrance point for an AP axial projection of the coccyx?

Increase the caudal angulation of the tube The x-ray tube should be angled 10 degrees caudad to place the beam perpendicular to the coccyx and separate the coccyx from the pubic symphysis. This will demonstrate the entire coccyx above the pubic symphysis. If there is superimposition of these structures, then the x-ray beam should be angled more caudally which will project the pubic symphysis lower on the image and away from the coccyx.

When evaluating an AP axial projection of the coccyx, the technologist notices that the obturator foramina are symmetrical, and that the coccyx is just superior to and in the same plane as the pubic symphysis and is superimposed by the bladder. What positioning error, if any, has been made with this image?

Increase the caudal angulation of the tube The x-ray tube should be angled 10 degrees caudad to place the beam perpendicular to the coccyx and separate the coccyx from the pubic symphysis. This will demonstrate the entire coccyx above the pubic symphysis. If there is superimposition of these structures, then the x-ray beam should be angled more caudally which will project the pubic symphysis lower on the image and away from the coccyx.

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.

Why is the lateral lumbar spine radiograph taken with the patient holding the breath in expiration?

It reduces the superimposition of the costophrenic angles and the first lumbar vertebra Suspended respiration is required to prevent motion on the image, and the preference is for suspended expiration. Expiration will elevate the diaphragm, eliminating superimposition of the costophrenic angles and the 1st lumbar vertebra. Suspended inspiration could result in the upper vertebrae lying within lung shadows, creating a much darker shade of gray for those structures.

When performing a lateral thoracic spine image the technologist sets technical factors of 50 mA and 3 seconds, rather than using automatic exposure control. What is the rationale for this choice of technical factors?

Lung and vascular marking will be blurred on the resulting image The use of a long time setting and low mA setting provides the time for a patient to breath during the exposure. The resulting breathing motion will blur the lung and vascular markings and ribs providing a better image of the thoracic vertebrae.

An AP projection of the coccyx demonstrates the coccyx superimposed by the superior rami of the pubic bones. What correction, if any, should be made?

No mistake has been made; this is an acceptable image A properly positioned AP axial coccyx image will demonstrate a symmetrical appearance of the obturator foramen and pubic bones. The coccyx should be free of superimposition by the pubic bones, and generally lies in the midline. The coccyx will normally be superimposed by the urinary bladder.

Should this image of the sacrum be repeated? Why or why not?

No, all required anatomy is included and the patient is correctly positioned When the patient is properly positioned for a lateral sacrum image, the bone should be demonstrated in lateral profile and the hip bones and femurs should be directly superimposed. This can easily be evaluated by examining the greater sciatic notches and the posterior borders of the ischial bones. Sacral foramina are visible on AP axial images of the sacrum rather than on the lateral.

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.

On this image of the lumbar spine, letter D refers to the:

Pedicle On this lateral image of the lumbar spine, letter A is pointing to the intervertebral foramen between L2 and L3; letter B is the spinous process of L2, letter C is pointing to the superimposed laminae of L3, and letter D is pointing to the superimposed pedicles of L4.

When radiographing the lumbar spine in the oblique position, the vertebral anatomy resembles a "scotty dog". The eye of the scotty dog represents which of the following?

Pedicle The oblique lumbar spine anatomy typically has the appearance of a "scotty dog" when the patient is positioned correctly. The eye of the dog corresponds to the pedicle of the vertebra; the ear corresponds to the superior articular process; the front leg corresponds to the inferior articular process; the nose corresponds to the transverse process; the neck corresponds to the pars interarticularis.

For an AP thoracic spine radiograph, the central ray is directed:

Perpendicular to the level of T7 Since the thoracic vertebrae increase in size from T1 through T12, T7 represents the center of this vertebral region. The jugular notch lies at the level of T2/T3; the sternal angle corresponds to T4/T5; and the xiphoid tip generally lies near the level of T10.

Which of the following bony landmarks lies at the same level as the superior border of the pubic symphysis?

Prominence of the greater trochanter While many radiographic positioning texts cite the pubic symphysis as a bony positioning landmark for abdominal and pelvic radiographs, it is embarrassing for many technologists to palpate this structure. It is therefore useful to remember that the prominence of the greater trochanter lies at the same level as the superior border of the pubic symphysis and the tip of the coccyx. Lateral rotation of the femur makes palpation of the greater trochanter easy and is less embarrassing.

Which of the following conditions would be indicated by the appearance of a collar on the scotty dog on an oblique lumbar spine radiograph?

Spondylolysis Spondylolysis is a condition in which there is a cleft in the pars interarticularis of a lumbar or cervical vertebra. The pars interarticularis corresponds to the neck of the scotty dog. A cleft or fracture is represented as a lucent line through the pars interarticularis.

Routine frontal lumbar spine images are typically performed with the patient in which of the following positions?

Supine on table with knees flexed Typically, for a frontal image of the lumbar spine the patient is positioned supine on the table. The knees are flexed for this procedure. Erect imaging of the spine may be used for certain orthopedic procedures to determine the effect of gravity on the spine.

The sacroiliac joints are classified as which of the following?

Synovial, gliding The SI joints are articulations between the auricular surfaces of the sacrum and the iliac bones. These joints are considered synovial, irregular gliding joints.________________

When in anatomic position, the inferior angle of the scapula corresponds to what vertebral level?

T7 The inferior angle of the scapula is a bony landmark that can easily be palpated. It corresponds to the level of T7 and is located approximately midway between the level of the jugular notch and the xiphoid process of the sternum.

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.

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.

The tubercle of a rib articulates with which portion of a thoracic vertebra?

Transverse process The tubercle of a rib articulates with the transverse process of a thoracic vertebra to form a costotransverse joint. While all thoracic vertebrae have costovertebral articulations, costotransverse joints are not present on the 11th and 12th vertebrae.