Chapter 15 - Spine Flashcards

Question

coccyx

Answer 1

In lay terms, it is called the tailbone. The coccyx usually consists of four small vertebral segments, but it is not unusual for there to be three or five segments. The coccygeal segments tend to fuse in the adult. The coccyx, the most inferior portion of the spine, is approximately the size of the fifth finger.

Answer 2

Together the sacrum and coccyx form a kyphotic curve. This curvature is more pronounced in females than in males.

Answer 3

The sacral base slopes downward anteriorly, and the degree of slope. This angle is greatest in females. It is greater when standing than when recumbent and is least when supine with the knees flexed.

Answer 4

The third (C3) through sixth (C6) cervical vertebrae are termed the typical cervical vertebrae

Answer 5

The four pairs of sacral foramina are passages for nerves.

Answer 6

Two small bony projections extend superiorly from the posterior aspect on each side of the first coccygeal segment.(singular cornu, which means “horn”)

Answer 7

Two small bony projections from the posterior inferior aspect of the sacrum. (singular cornu, which means “horn”)

Answer 8

the upper cervical spine (C1 and C2) and the lumbosacral junction, but it may be helpful in any area of the spine. The limited operator must be able to correctly identify the location of any vertebra when a coned-down radiograph is necessary.

Answer 9

Two radiographs are necessary to demonstrate the entire cervical spine in the AP projection.

Answer 10

To demonstrate the upper cervical vertebrae, a second AP projection is taken through the open mouth. This projection is sometimes referred to as the AP open-mouth or the odontoid projection.

Answer 11

Detail is also enhanced by the use of the small focal spot.

Answer 12

This results in a large object–image receptor distance (OID) between the neck and the IR. To minimize magnification and improve detail on this projection, a 72-inch source–image receptor distance (SID) is used. Detail is also enhanced by the use of the small focal spot.

Answer 13

the AP axial (lower cervical), AP (upper cervical), and lateral projections.

Answer 14

SID 40 inches minimum Body position Seated, standing, or supine. Part position Midsagittal plane of both body and head are aligned perpendicular to center of IR, with patient facing tube. Head position is adjusted so that a line between mental point and base of skull makes an angle of 15 degrees with horizontal plane (Fig. 15.22). When patient is recumbent, patient’s head rests on table (Fig. 15.23). Head is placed firmly against IR holder when upright. If desired position cannot be attained in this way, a radiolucent wedge sponge is placed under/behind head for stability. Tip The upper margin of the collimator light field will fall across the patient’s face at an angle of 15 degrees, which simplifies the adjustment of the head position. Central ray Centered with regard to IR at an angle of 15 degrees cephalad through thyroid cartilage. Structures seen Vertebrae C3 through T2, including bodies, articular pillars, and intervertebral disk spaces (Fig. 15.24).

Answer 15

SID 40 inches minimum (30 inches may be used to increase the odontoid area field of view) Body position Seated, standing, or supine. Part position Patient faces tube with midsagittal plane of both body and head perpendicular to center of IR. Position of head is adjusted so that a line between lower surface of upper teeth (occlusal plane) and base of skull is parallel to horizontal plane (Figs. 15.25 and 15.26). When patient is upright, patient’s head is placed firmly against IR holder or a radiolucent wedge sponge for stability. Central ray Perpendicular to center of IR, through midpoint of open mouth. Patient instruction Open mouth as wide as possible. Stop breathing. Do not move. Tip If the patient has closed the mouth following positioning and must reopen it before the exposure, it is wise to instruct the patient to “drop the lower jaw” as far as possible. When instructed to “open wide,” patients may tend to extend the neck, which causes incorrect position of the head. Structures seen Lateral masses and transverse processes of atlas, dens, and upper half of body of axis, seen between upper and lower teeth (Fig. 15.27). Tip If the base of the skull is superimposed on the atlas and the dens, then the patient’s neck was extended too far. If the upper teeth are superimposed on the atlas and the dens, then the patient’s neck was flexed too much. If the lower teeth are superimposed on the upper half of the axis and the base of the skull is in the proper position, the patient’s mouth was not open far enough.

Answer 16

SID 60 to 72 inches (152 to 183 cm) is recommended because of the increased OID Body position Seated or standing. Part position Midsagittal planes of body and head are parallel to IR with infraorbitomeatal line parallel to floor. Shoulders must be relaxed and depressed. IR is positioned so that upper margin is about 1 inch above the external auditory meatus (EAM) (Fig. 15.28). Tip Patients with high, square shoulders may need to have sandbags of equal weight suspended from the wrists to place the shoulders below C7 (see Fig. 13.104). Alternatively, patient may stand on the center of a long strap, grasping the two ends to maintain downward tension on the shoulders. Central ray Perpendicular to center of IR through body of C4. Tip Place your finger on the tip of the C7 spinous process and note the location of its shadow in the collimator light beam. It should be within the posterior margin of the IR and at least 2 inches above its inferior margin. Patient instruction Stop breathing. Do not move. Tip Do not instruct patient to “take a deep breath” because doing so tends to elevate the shoulders. Structures seen All seven cervical vertebrae and soft tissues of anterior neck, including spinal alignment, bodies, disk spaces, spinous processes, and zygapophyseal joints (Fig. 15.29). Note When a good effort has been made to lower the shoulders for the lateral cervical spine projection but the radiograph fails to demonstrate C7, it is necessary to supplement the examination with the lateral projection of the cervicothoracic region, described later in this chapter.

Answer 17

SID 60 to 72 inches (152 to 183 cm) is recommended because of the increased OID Position for flexion Patient is positioned as for routine lateral projection. Patient is then instructed first to “tuck” chin close to neck and then to flex neck, attempting to look at a spot at midsternum (Fig. 15.30). Position for extension Patient is positioned as for routine lateral projection. Patient is then instructed to extend neck, looking at a spot on ceiling directly above head (Fig. 15.31). Note The radiographer must not force these positions. The desired degree of flexion or extension is the fullest extent that is tolerable for the patient. Central ray Perpendicular to center of IR, through body of C4. Patient instruction Stop breathing. Do not move. Structures seen All seven cervical vertebrae and soft tissues of anterior neck, including spinal alignment, bodies, disk spaces, spinous processes, and zygapophyseal joints. Head tilted face down in flexion (Fig. 15.32) and tilted face up in extension (Fig. 15.33).

Answer 18

Oblique projections are taken in left/right pairs. They may be done in a posteroanterior (PA) projection (right anterior oblique [RAO] and left anterior oblique [LAO] positions) or AP projection (right posterior oblique [RPO] and left posterior oblique [LPO] positions).

Answer 19

SID 60 to 72 inches (152 to 183 cm) is recommended because of the increased OID Body position Seated, standing, or recumbent. Part position Coronal plane of body forms angle of 45 degrees with plane of IR. Sagittal plane of skull is perpendicular to coronal plane of body. Have patient elevate and, if necessary, protrude the chin so that mandible does not overlap spine. Central ray AP obliques Angled 15 degrees cephalad to center of IR through body of C4 (Figs. 15.34 and 15.35). PA obliques Angled 15 degrees caudad to center of IR through body of C4 (Figs. 15.37 and 15.38). Patient instruction Stop breathing. Do not move. Structures seen AP obliques demonstrate intervertebral foramina on side farthest from IR (Fig. 15.36). PA obliques demonstrate intervertebral foramina on side nearest IR (Fig. 15.39).

Answer 20

SID 40 inches minimum Body position Seated, standing, or recumbent. Part position Sagittal planes of body and head are parallel to IR. Arm nearest IR is raised above head and shoulder is rounded anteriorly. Opposite shoulder is depressed and slightly posterior (Figs. 15.40 and 15.41). Central ray Perpendicular to IR at C7–T1 interspace. Central ray enters at base of neck in midcoronal plane at level of C7 spinous process. Patient instruction Stop breathing. Do not move. Structures seen Vertebrae C6 through T3 (C5 through T5 with larger IR) in lateral projection without significant rotation. Bodies, disk spaces, spinous processes, and zygapophyseal joints are demonstrated between shoulders (Fig. 15.42). Tip Take care when positioning the arms so that the midsagittal plane of the body remains parallel to the IR. The most common error associated with this position is rotation of the body so that the spine is oblique rather than lateral. Compensating filter This projection will be improved with the use of a compensating filter because of the extreme difference between the thin lower neck and the very thick upper thoracic region. With the use of a specially designed filter, the C7–T1 area can be more clearly seen.

Answer 21

For this reason, it is desirable to use the anode heel effect

Answer 22

For this reason, it may be desirable to reverse the position of the compensating filter for the lateral projection. In any case, the first three thoracic vertebrae are seldom visualized well on the lateral projection. When the area of clinical interest includes the upper thoracic vertebrae, it is usual for the examination to include a swimmer’s lateral projection of the cervicothoracic region.

Answer 23

the AP and lateral projections.

Answer 24

SID 40 inches minimum Body position Seated, standing, or recumbent. Part position Midsagittal plane of body is perpendicular to IR and centered on it, with patient facing tube. Superior border of IR is aligned 1.5 to 2 inches (3.8 to 5 cm) above the shoulders (Figs. 15.43 and 15.44). When patient is supine, it is helpful to place a bolster under knees. When patient is standing, feet should be shoulder-width apart with equal weight bearing, and patient’s back should be firmly against IR holder. Central ray Perpendicular to center of IR at T7. This point is in midline at approximate midpoint of sternum. Patient instruction Do not move. Suspend breathing on expiration. Structures seen All 12 thoracic vertebrae, particularly the bodies, disk spaces, and transverse processes. C7 and at least a portion of L1 are usually also seen (Fig. 15.45). Compensating filter The image quality of this projection can be improved significantly with use of a compensating filter. Various wedge filters are available to assist in providing a uniform density of the entire thoracic spine.

Answer 25

SID 40 inches minimum Body position Seated, standing, or recumbent. Part position Sagittal plane of body is parallel to IR. Center the posterior half of the thorax to the midline of the IR. Arms may be raised overhead (Fig. 15.46) or anterior to body with shoulders rounded anteriorly (Fig. 15.47). The superior border of the IR is adjusted to 1.5 to 2 inches (3.8 to 5 cm) above the shoulders. Take care that entire length of thoracic spine is parallel to IR. When patient is recumbent, this may require support of a radiolucent sponge under waist and/or hips. Central ray Perpendicular to center of IR at level of T7. Central ray enters at inferior angle of scapula through middle of posterior half of thorax. Tip Place a strip of lead or a lead rubber mask behind the patient so that its margin is aligned with the shadow of the patient’s back in the collimator light. This absorbs backscatter and improves visualization of the spinous processes. Patient instruction Do not move. Perform shallow breathing during exposure. Tip A low milliamperage (mA) setting that provides the desired milliampere-seconds (mAs) with an exposure time of 1 to 3 seconds is necessary for best results with breathing technique. Structures seen T3 through T12 with blurring of ribs and lung markings when breathing technique is used (Fig. 15.48).

Answer 26

the AP or PA and lateral projections.

Answer 27

SID 40 inches minimum Body position Standing or recumbent. Part position AP Patient faces tube with midsagittal plane perpendicular to IR and centered on it (Fig. 15.49). When patient is supine, knees are flexed and may be supported with a bolster. When patient is standing, feet are shoulder-width apart with equal weight bearing, and torso is stabilized against upright IR holder (Fig. 15.50). PA Patient stands facing IR or lies prone, with midsagittal plane perpendicular to IR and centered on it. Central ray Perpendicular to center of IR through L4, in midline at level of iliac crest. Structures seen All five lumbar vertebrae, intervertebral disk spaces, proximal portion of sacrum, and SI joints. This projection demonstrates the bodies, disk spaces, and transverse processes. The pedicles are seen on end. When a 35-×43-cm IR is used, central pelvis and hip joints may be visualized if collimation is not too close (Figs. 15.51 and 15.52). Visualization of hip joints is particularly important to demonstrate pelvic tilt when an upright AP projection is taken.

Answer 28

SID 40 inches minimum Body position Standing or recumbent. Part position Sagittal plane is parallel to IR. Recumbent In lateral recumbent position, spine is aligned parallel to center of Bucky with arms anterior to body. Radiolucent sponges may be used to elevate waist and/or hip to keep spine level (Fig. 15.53). Knees are flexed. A pad between knees helps keep pelvis lateral and maintain lateral position of spine. Upright Feet are shoulder-width apart with equal weight bearing, and torso is stabilized against upright IR holder. Arms are crossed over chest with hands supported on shoulders. Alternatively, arms may be supported out of radiation field by having patient grasp a pole (Fig. 15.54). Central ray Perpendicular to center of IR through L4, in midaxillary line at level of iliac crest. Tip Place a strip of lead or a lead rubber mask behind the patient so that its margin is aligned with the shadow of the patient’s back in the collimator light. This absorbs scatter and improves visualization of the spinous processes. Patient instruction Do not move. Suspend breathing on expiration. (Respiratory phase is particularly important on the lateral projection. If exposed on inspiration, the posterior lung fields will superimpose the body of L1.) Structures seen All five lumbar vertebrae and superior half of sacrum, including intervertebral foramina, spinous processes and profile of the bodies, and intervertebral disk spaces (Fig. 15.55).

Answer 29

SID 40 inches minimum Body position Standing or recumbent. Part position Sagittal plane is aligned at angle of 45 degrees to IR. Recumbent From supine position, patient is rotated 45 degrees toward side being radiographed (Fig. 15.56). Position may be supported by a large 45-degree-angle radiolucent sponge. Take care that the entire spine is rotated the same amount so there is no torsion (twist) of spine. Upright From AP position, patient is rotated 45 degrees toward side being radiographed. Feet are shoulder-width apart bearing equal weight, and torso is stabilized against upright IR holder (Fig. 15.57). Central ray Perpendicular to center of IR through L3. Central ray enters at point 2 inches medial to anterior superior iliac spine (ASIS) farthest from IR and 1.5 inches superior to iliac crest. Patient instruction Do not move. Suspend breathing on expiration. Structures seen All five lumbar vertebrae and upper portion of sacrum, including zygapophyseal joints and pars interarticularis on the side nearest the IR (Fig. 15.58).

Answer 30

SID 40 inches minimum Body position As for routine lateral lumbar projection, with care taken that spine is parallel to IR (Fig. 15.59). Central ray Directed perpendicular to center of IR through lumbosacral joint. This centering point is 2 inches posterior to ASIS and 1.5 inches inferior to iliac crest on coronal line midway between ASIS and posterior prominence of sacrum. When spine cannot be supported, angle 5 degrees caudad for males and 8 degrees caudad for females. Patient instruction Do not move. Suspend breathing on expiration. Structures seen The lower one or two lumbar vertebrae, the upper sacrum, and an open lumbosacral junction (Fig. 15.60).

Answer 31

SID 40 inches minimum Body position Supine, as for AP recumbent lumbar spine, with knees flexed and supported. Central ray Angled 30 degrees cephalad for males and 35 degrees cephalad for females. It is directed to center of IR through lumbosacral junction (Fig. 15.61). Central ray enters in midline, 1 inch inferior to the ASIS (Fig. 15.62). Structures seen Open lumbosacral junction, sacral alae, and SI joints (Fig. 15.63).

Answer 32

the AP oblique projections. The AP axial projection of the lumbosacral junction and the SI joints may also be included.

Answer 33

SID 40 inches minimum Body position Recumbent. Part position AP obliques (RPO, LPO positions) From supine position, body is rotated so that coronal plane is aligned at angle of 25 to 30 degrees to IR (Fig. 15.64). The side of interest is elevated, furthest from IR (Fig. 15.65). Position may be supported by radiolucent sponge under hip and lumbar area of elevated side. Take care the entire spine is rotated the same amount so that there is no torsion of spine. PA obliques (RAO, LAO positions) From prone position, body is rotated so that coronal plane is aligned at angle of 25 to 30 degrees to IR. Side of interest is nearest the IR. This position may be supported by radiolucent sponge under hip and abdomen area on opposite side. Take care the entire spine is rotated the same amount so that there is no torsion of spine. Central ray AP obliques Perpendicular to center of IR through point 1 inch medial to ASIS farthest from IR. PA obliques Perpendicular to center of IR through point 1 inch medial to ASIS nearest the IR. Patient instruction Do not move. Suspend breathing on expiration. Structures seen AP obliques SI joint farthest from IR (Fig. 15.66). PA obliques SI joint nearest IR.

Answer 34

the AP axial and lateral projections.

Answer 35

SID 40 inches minimum Body position Recumbent or supine. Part position Midsagittal plane is perpendicular to IR and centered to it. Knees are flexed and supported with a bolster, if needed. Central ray Angled 15 degrees cephalad to enter body at midline, 1 inch inferior to the ASIS (Fig. 15.67). Patient instruction Stop breathing. Do not move. Structures seen Entire sacrum and SI articulations (Fig. 15.68).

Answer 36

SID 40 inches minimum Body position Recumbent. Part position Sagittal plane is parallel to IR. Recumbent Spine is aligned parallel to center of Bucky with arms anterior to body. Radiolucent sponges may be used to elevate waist and/or hips to keep spine level (Fig. 15.69). Knees are flexed. A pad between knees helps maintain lateral position of pelvis and spine. Central ray Perpendicular to center of IR through center of sacrum. Central ray enters at point 3.5 inches posterior to ASIS (Fig. 15.70). Tip Place a strip of lead or a lead rubber mask behind the patient so that its margin is aligned with the shadow of the patient’s back in the collimator light. This absorbs backscatter and improves contrast resolution of the sacrum image. Patient instruction Do not move. Suspend breathing on expiration. Structures seen Entire sacrum and lumbosacral junction (Fig. 15.71). Coccyx is sometimes seen.

Answer 37

the AP axial and lateral projections.

Answer 38

SID 40 inches minimum Body position Recumbent. Part position Coronal plane is parallel to IR with patient facing tube. Midsagittal plane is centered to midline of Bucky. When patient is supine, knees are flexed and supported with a bolster, if needed. Central ray Angled 10 degrees caudad to enter body in midline, 1 inch inferior to the ASIS (Fig. 15.72). Patient instruction Do not move. Structures seen Entire coccyx and distal portion of sacrum (Fig. 15.73).

Answer 39

SID 40 inches minimum Body position Recumbent. Part position Sagittal plane is parallel to IR. When patient is recumbent, knees are flexed and may be separated by a sponge or cushion (Fig. 15.74). Central ray Perpendicular to center of IR through center of coccyx. Central ray enters at point 2 inches inferior to ASIS level and 3.5 inches posterior to ASIS. Tip Place a strip of lead or a lead rubber mask behind the patient so that its margin is aligned to the shadow of the patient’s back in the collimator light. This absorbs backscatter and improves contrast resolution of the coccyx image. Patient instruction Do not move. Structures seen Entire coccyx and distal portion of sacrum (Fig. 15.75).

Answer 40

SID 60 inches minimum Position Upright as for standing PA lumbar spine projection. Height of grid and IR is adjusted to include area from top of patient’s ears to level of greater trochanters (Fig. 15.76). Head is positioned as for AP axial projection of upper cervical spine, with neck extended slightly to allow for angulation of diverging x-ray beam at upper extreme of exposure field. Central ray Aligned perpendicular to center of IR, entering at midline approximately at level of xiphoid process. Patient instruction Stop breathing. Do not move. Structures seen Portion of mandible, entire spine, portion of pelvis (Figs. 15.77 and 15.78). Compensating filter The wide range of body part thicknesses and tissue densities in the thoracic and abdominal areas necessitates the use of specially designed compensating filters to create a more uniform radiographic brightness throughout the entire spine.

Answer 41

SID 60 inches minimum Position Same as for upright lateral projection of thoracic spine. Shoulders are rounded anteriorly and arms are extended anterior to body and supported (Fig. 15.79). Patient instruction Stop breathing. Do not move. Structures seen Portion of mandible and skull, entire spine, portion of pelvis (Fig. 15.80). Compensating filter The wide range of body part thicknesses and tissue densities in the thoracic and abdominal areas necessitates the use of specially designed compensating filters to create a more uniform radiographic density (brightness) throughout the entire spine.

Answer 42

Sometimes one or both spinous processes of L5 become fused to the sacrum

Answer 43

Usually spina bifida is relatively insignificant and produces no symptoms,

Answer 44

Less commonly, the defect may be quite large, leaving the spinal cord unprotected;

Answer 45

In bones weakened by disease processes, fractures may occur with little or no trauma.

Answer 46

are often seen in elderly women (Fig. 15.86).

Answer 47

refers to fixation or fusion of vertebrae.

Answer 48

has the suffix -itis, which you may recall indicates inflammation. This term is often applied specifically to tuberculous disease of the vertebrae, which is also called Pott disease. Spondylitis is also seen with rheumatoid arthritis.

Answer 49

refers to the breakdown of the structure of the bone. This occurs with osteoporosis, with some metastatic lesions, and with other conditions that cause atrophy and bony destruction.

Answer 50

refers to the anterior displacement of one vertebra on another (Fig. 15.90). It occurs most commonly at the lumbosacral joint and is usually caused by a defect or a fracture of the pars interarticularis or of the pedicle.

Answer 51

is the term for a congenital fissure (split or cleft) in the neural arch.

Answer 52

With advancing age and repeated minor traumas to the spine, the disks tend to degenerate. The nucleus may dry out and become atrophied, which causes narrowing of the disk space. Without adequate cushioning, the joint becomes inflamed, and the surrounding bony structures show the characteristic signs of degeneration: sclerotic (hardened), irregular bone margins with hypertrophic lipping and spurring. This condition is called degenerative disk disease (DDD) and is usually associated with osteoarthritis.

Answer 53

is the condition often called, in lay terms, a slipped disk. The annulus fibrosus ruptures, and the nucleus is forced into the area posterior to the disk space (Fig. 15.92). The displaced nucleus causes pressure on the spinal cord and/or the nerve roots in this area.

Answer 54

Disk herniation may cause acute pain, chronic discomfort, or recurrent painful episodes involving the site of the herniation. There may also be pain, numbness, or altered sensation in areas remote from the spine.

Answer 55

Myelography, discography, computed tomography, and magnetic resonance imaging studies (Fig. 15.93) may be used to identify disk pathology.

Answer 56

pain along the path of the sciatic nerve in the buttock, posterior thigh, and leg. It is caused by nerve irritation in the lumbar region. Damage to nerve roots may cause weakness or paralysis. The function or control of organs may be affected as well.

Answer 57

narrowing of the intervertebral foramina

Answer 58

7 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 4 coccygeal.

Answer 59

an anterior body, a posterior vertebral arch, two lateral projections called transverse processes, and a posterior projection called the spinous process.