Ch. 9 Lumbar Spine, Sacrum, and Coccyx Workbook Flashcards
a portion of the lamina located between the superior and inferior articular processes is called this
pars interarticularis
the superior and inferior vertebral notches join together to form this
intervertebral foramina
which radiographic position best demonstrates the intervertebral foramina of the lumbar spine
lateral position
what does the oblique position of the lumbar spine best demonstrate
zygapophyseal joints
the small foramina found in the sacrum are called what
pelvic sacral foramina
the anterior and superior aspect of the sacrum that forms the posterior wall of the pelvic inlet is called this
promontory
what is another term for the sacral horns
cornua
the sacroiliac joints lie at an oblique angle of what to the coronal plane
30 degrees
formal term for tailbone
coccyx
what is the name of the superior broad aspect of the coccyx
base
what type of joint is the zygapophyseal joint
diarthrodial, synovial - plane (gliding)
what type of joint is the intervertebral joint
amphiarthrodial, cartilaginous - symphysis
what is demonstrated in the LPO lumbar position
left zygapophyseal joint
what is demonstrated in the RAO lumbar position
left zygapophyseal joint
what is demonstrated in the lateral lumbar position
intervertebral foramina
what is demonstrated in the RPO lumbar position
right zygapophyseal joints
what is demonstrated in the LAO lumbar position
right zygapophyseal joints
what is the degree of obliquity required for a projection of the T12-L1 level
50 degrees
what is the degree of obliquity required for a projection of the L5-S1 level
30 degrees
what is the obliquity required for a general lumbar spine
45 degrees
what level is ASIS at
S1-S2
what level is the xiphoid process at
T9-T10
what level is the lower costal margin at
L2-L3
what level is iliac crest at
L4-L5
what level is the prominence of the greater trochanter at
symphysis pubis
should gonadal shielding always be used for male and female patients
no - just always males, only females if it doesn’t obscure anatomy
what position opens up the intervertebral joint spaces better
PA
how should the knees and hips be positioned for a recumbent AP projection of the lumbar spine
they should be flexed
when positioning an obese patient, the iliac crest is typically at the level of this
inferior margin of the flexed elbow
what imaging modality would be used to see osteoporosis
bone densitometry
what imaging modality would be used to see soft tissues of the lumbar spine
MRI
what imaging modality would be used to see structures within the subarachnoid space
MRI and/or myelography
what imaging modality would be used to see inflammatory conditions such as paget disease
nuclear medicine
what imaging modality would be used to see compression fractures of the lumbar spine
CT
this is lateral curvature of the vertebral column
scoliosis
this is a fracture of the vertebral body caused by hyperflexion force
chance fracture
this is a congenital defect in which the posterior elements of the vertebrae fail to unite
spina bifida
most common at the L4-L5 level and may result in sciatica
herniated nucleus pulposus
forward displacement of one vertebra onto another vertebra
spondylolisthesis
inflammatory condition that is most common in males in their 30s
ankylosing spondylitis
dissolution and separation of the pars interarticularis
spondylolysis
a type of fracture that rarely causes neurologic deficits
compression fracture
with a 14x17 IR where is CR for an AP and lateral lumbar spine
iliac crest
which two structures can be evaluated to determine whether rotation is present on a radiograph of an AP projection of the lumbar spine
- SI joints equidistant to spine
- spinous process midline to vertebral column
how much rotation is required to visualize the zygapophyseal joints properly at the L5-S1 level
30 degree
which specific set of zygapophyseal joints is demonstrated with an LAO position
right
this is the eye of the scottie dog, and it should be near the center of the vertebral body on a correctly oblique lumbar spine position
pedicle
what positioning error has been committed if the pedicle is projected too far posterior with a 45 oblique position of the lumbar spine
over rotated
which position or projection of the lumbar spine series best demonstrates a possible compression fracture
lateral
a patient with a wide pelvis and narrow thorax may require this on the lateral position for the lumbar spine
5-8 degree caudal angle
how should the spine of a patient with scoliosis be positioned for a lateral position of the lumbar spine
convex side down, closer to IR
why should the knees and hips be flexed for a recumbent AP lumbar spine projection
less curvature of the spine and opens up the intervertebral joint spaces
how much female ovarian dose is a PA lumbar v. an AP lumbar
25-30%
where is CR for a lateral L5-S1 projection of the lumbar spine
1.5” below crest and 2” posterior to ASIS
what is the amount and direction of CR angulation required for an AP axial L5-S1 projection on a male
30 degrees cephalic
a scoliosis series frequently includes these for comparison
erect and recumbent
what must the lower margin of the IR for the scoliosis series include
1-2” below iliac crest
a PA projection for scoliosis series produces how much less dose to the breasts as compared with the AP projection
1/10 the dose
what produces a more uniform density along the vertebral column for an AP/PA scoliosis projection
compensating filter
which side of the spine should be elevated for the second exposure for the AP/PA projection (Ferguson method) scoliosis series
elevate side with the convexity
for the Ferguson method, the elevated foot must be raised a minimum of how much
3-4” (8-10 cm)
during the AP/PA right and left bending projections of the lumbar spine, this serves as a fulcrum during positioning
pelvis
which projection should be taken to evaluate flexibility following spinal fusion surgery
hyperextension and hyperflexion lateral projections
what is the recommended kVp range for lateral hyperflexion and hyperextension positions of the spine for a digital imaging system
80-95
how much CR angulation is required for an AP projection of the sacrum for a typical male pateint
15 degrees cephalic
where is the CR centered for an AP axial projection of the sacrum
2” superior to pubic symphysis
if a patient cannot lie on his back for the AP sacrum because it is too painful, what alternate projection can be taken to achieve a similar view of the sacrum
PA sacrum with a 15 degree caudal angle
where is the CR centered for an AP projection of the coccyx
2” above pubic symphysis
how much is the CR angled for the AP axial coccyx projection
10 degrees caudal
can the AP projection of the sacrum and coccyx be taken as 1 single projection to decrease gonadal dose
no - just the lateral can
patients should be asked to empty the urinary bladder before performing which projection of the vertebral column
AP of sacrum and coccyx
in addition to good collimation, what should be done to minimize scatter radiation on a lateral lumbar spine or lateral sacrum and coccyx radiograph
place a lead mat/masking behind patient on table
which SI joint is visualized with an RPO position
left
how much rotation of the body is required for oblique positions of the SI joints
25-30 degrees
what type of CR angulation is recommended for the AP axial projection of the SI joints on a female patient
35 degrees cephalad
where is the CR centered for an oblique projection of the SI joints
1” medial to upside ASIS
a radiograph of an AP projection of the lumbar spine shows the spinous processes are not midline to the vertebral column and distortion of the vertebral bodies is present. What positioning error is present
rotation of the spine
a radiograph of an LPO projection of the lumbar spine shows the pedicles and zygapophyseal joints are projected over the anterior portion of the vertebral bodies. what positioning error is present
under rotation
a radiograph of a lateral projection of a female lumbar spine shows the mid- to lower intervertebral joints spaces are not open. the tech supported the mid section of the spine with sponges to straighten the spine. what else can be done to open the joint spaces during the repeat exposure
angle 5-8 degrees caudad
a radiograph of a lateral L5-S1 projection shows the joint space is not open. the tech did support the middle aspect of the spine with a sponge. what else can the tech do to open up the joint space during the repeat exposure
angle 5-8 degrees caudad or place additional support beneath spine
a radiograph of an AP axial projection of the coccyx shows the distal tip is superimposed over the symphysis pubis. what must the tech do to eliminate this problem during the repeat exposure
increase CR angle
a radiograph of an oblique position of the lumbar spine shows the pedicle and zygapophyseal joint are posterior in relation to the vertebral body. what modification of the position must be made during repeat image
over rotation
a patient comes to the radiology department for a follow-up study for a compression fracture of L3. the radiologist requests that collimated projections be taken of L3. what specific projections and centering would provide a quality study of L3
AP and lateral collimated to L3, centered about 2” above iliac crest
a young female patients comes in for a scoliosis series, how can you limit their dose delivered
- shoot PA rather than AP
- use breast shields
- use high kVp and low mAs
a patient with an injury to the coccyx enters the ER. Patient complains that lying on their back is too painful, what else can be done to get the AP image
PA angled 10 cephalic instead of caudal
a patient with a clinical history of spondylolisthesis at the L5-S1 level comes in. what lumbar spine position is most diagnostic in demonstrating the extent of this condition
lateral L5-S1
a positioning series for SI joints is performed on a patient. the resultant radiographs do not demonstrate the inferior portion of the joints. what can be done to demonstrate this aspect
angle 15-20 degrees cephalic
a patient comes to the radiology department for a lumbar series. He has clinical history of advanced spondylolysis. what projection of the lumbar spine series will best demonstrate this condition
obliques best demonstrate it
a patient comes to the radiology department with a clinical history of HNP/ what imaging modalities provide the most diagnostic study for this condition
MRI
a patient comes to the radiology department for a lumbar spine study following spinal fusion surgery. her surgeon wants a study to assess mobility of the spine at the fusion site. which radiographic positions provide this
hyperextension and hyperflexion lateral positions
a patients comes to the radiology department for a lumbar spine series. she has a clinical history of severe kyphosis. how should the lumbar spine series be modified for this patient
routine lumbar in an erect position