L-Spine, Sacrum, and Coccyx Self Test Questions

Question 1

Compared with the spinous processes of the C- and T- spine, the lumbar spinous processes are:

Answer 1

larger and more blunt

Question 2

The anterior/superior ridge of the upper sacrum is called the:

Answer 2

promontory

Question 3

Each SI joint opens obliquely _____ degrees posteriorly

Answer 3

30

Question 4

The angle of the midlumbar spine zygapophyseal joints in relation to the midsagittal plane is:

Answer 4

30-50°

Question 5

Where is the pars interarticularis found?

Answer 5

between the superior and inferior articular processes

Question 6

The Z joints of the lumbar spine are classified as _________, as joints with ______________ type of joint movement.

Answer 6

synovial; plane (gliding)

Question 7

The ear and front leg of the Scottie dog make up the ______ joint, best seen in the oblique position.

Answer 7

Z

Question 8

Which of the following topographic landmarks corresponds to the L2-L3 level?

xiphoid process
lower costal margin
iliac crest
ASIS

Answer 8

lower costal margin

Question 9

It is possible to shield females for an AP projection of the sacrum or coccyx if the gonadal shields are correctly placed.

Answer 9

false

Question 10

Why should the knees and hips be flexed for a recumbent AP projection of the lumbar spine?

Answer 10

reduces lumbar curvature (lordosis)

Question 11

A lead mat or masking for lateral positions of the lumbar spine should not be used with digital imaging.

Answer 11

false

Question 12

Anterior wedging and loss of vertebral body height are characteristic of:

Answer 12

compression fracture

Question 13

Which of the following conditions is often diagnosed by prenatal ultrasound?

scoliosis
spina bifida
spondylolisthesis
spodylosis

Answer 13

spina bifida

Question 14

Ankylosing spondylitis usually requires an increase in manual exposure factors.

Answer 14

false

Question 15

Where is the CR centered for an AP projection of the lumbar spine with a 11- x 14-inch IR?

Answer 15

L3

Question 16

Which set of Z joints of the lumbar spine is best demonstrated with an LAO position?

Answer 16

right

Question 17

How much rotation of the spine is required to demonstrate the Z joint space between L1-L2?

Answer 17

50°

Question 18

Describe the body build that might require CR angulation to open the intervertebral joint spaces with a lateral projection of the lumbar spine, even if the pt has some support under the waist.

Answer 18

pt w/ wider pelvis and narrow thorax

Question 19

What type of CR angulation should be used for the lateral L5-S1 projection if the waist is not supported?

Answer 19

5-8° caudad

Question 20

For the lateral L5-S1 projection the CR is parallel to the ___________ plane.

Answer 20

interiliac

Question 21

Where is the CR centered for an AP axial projection for L5-S1?

Question 22

A kVp of 90-100 can be used for a lateral L5-S1 projection when using a digital imaging system.

Answer 22

true

Question 23

Which projection or method is designed to demonstrate the degree of scoliosis deformity between the primary and compensatory curves as part of a scoliosis study?

Answer 23

AP/PA series - Ferguson method

Question 24

What projections are designed to measure mobility of the vertebral column at the site of a spinal fusion?

Answer 24

hyperextension/hyperflexion lateral

Question 25

Where is the CR centered for an AP projection of the sacrum?

Answer 25

2 in. superior to pubic symphysis

Question 26

What two things can be done to reduce the high amounts of scatter reaching the IR during a lateral projection of the sacrum and coccyx?

Answer 26

close collimation and lead mat

Question 27

Why should a single lateral projection of the sacrum and coccyx be performed rather than the separate laterals of the sacrum and coccyx?

Answer 27

decrease gonadal dose

Question 28

The pelvis must remain as stationary as possible when positioning for the hyperextension and hyperflexion projections.

Answer 28

true

Question 29

A radiograph of an AP projection of the lumbar spine shows the SI joints are not equidistant from the spine. The right ala of the sacrum appears wider, and the right SI joint is more open than the left. Which specific positioning error is evident on this radiograph?

Answer 29

rotation to right

Question 30

A radiograph of an LPO projection of the lumbar spine shows the downside pedicles are projected toward the posterior aspect of the vertebral bodies. What must be done to correct this error?

Answer 30

ensure no rotation of spine an be sure pt is at 45°

Question 31

An AP projection of the sacrum shows that the sacrum is foreshortened and the foramina are not open. What positioning error may have led to this radiograph outcome?

Answer 31

CR alignment

Question 32

A patient with a possible compression fracture of L3 enters the emergency room. Which projection(s) of the lumbar spine best demonstrate(s) the extent of this injury?

Answer 32

AP and lateral

Question 33

A pt with a clinical history of spondylolisthesis of the L5-S1 region comes to the radiology dpt. What basic and special projections should be included in this study?

Answer 33

R and L oblique l-spine rotated 30°
AP lateral L5-S1
“spot”???????????????????????????

Question 34

A study of the SI joints demonstrates that the joints are not open and the upper iliac wings are nearly superimposing the joints. The tech performed 35° RPO and LPO positions with a perp. CR. What can be done during the repeat exposure to open the joints?

Answer 34

ensure a 25-30° oblique of pt