spine ch 23 Flashcards
what is the study of choice for most diseases of spine
MRI because of
- its ability to visualize and detect abnormaities in soft tissues, such as bone marrow, the cpinal cord, and the intervertebral disks;
- its ability to display images in any plane
- and the lack of radiation
Components of almost every vertebra
Almost every vertebra has a
- body composed of inner cancelous bone and marrow and
- posterior elements made of compact dense bone consisting of the pedicles, laminae, facets, transverse processes and a spinous process.
what vertebrae are rectangular in shape
from the level of c3-L5
what type of joint are facet joints? (superior and inferior articular processes joint)
true synovial joint
Where are two ovoid pedicles not visible?
at the level L5 because of lordosis of the lumbar spine
Relative height of the disk space varies in each aprt of the spine. How is it in : - cervical spine - thoracic spine - lumbar spine
- In the cervical spine, the disk spaces are about equal to each other in height.
- In the thoracic spine, they are usually slightly decreased in size from the cervical spine, but equal in height to each other
- In the lumbar spine, the disk paces progressively increase in height with each successive interspace, except for L5-S1, which can be equal to or slightly less than the height of L4-L5
What structure does “Scottie dog” represent
oblique view of lumbar spine: ear: superior art facet leg : inferior art facet nose- transverse process neck: pars interarticularis
Where does spinal cord end
spinal cord extends from the medulla oblongata to the level of L1-L2, ending as the conus medullaris
how are spinal nerves named
- from c1-c7, they exit above the vertebrae that they are named after
- C8 nerve exits between the 7th cranial and 1st thoracic vertebrae
- remaining nerves exit below their respectively numbered vertebrae.
On T1-weighted saggital MRI images of the spine, the vertebral bodies, containgin bone marrow will be of ____ signal intensity, the disks will be ____ in signal intensity.
vertebral bodies - high signal intensity = bright
disks - low signal intensity dark
On conventional T2 weighted images, the vertebral body will be _____ compared to disks.
CSF will appear ____.
on T2, vertebral bodies will be slighlty brighter than disks.
CSF will be bright
Cortical bone is ____ on all sequences.
dark
List some of the causes of back pain
- herniation of an intervertebral disk
- degenerative disk disease
- osteoarthritis of facet joints
- diffuse idiopathic skeletal hyperostosis (DISH)
- compression fractures of the spine
- spinal stenosis
In the lumbar region, disk herniation may lead to ___ and ___, whereas herniation of a cervical disk may produce ___ and ____.
lumbar : back pain and sciatica
cervical : radiculopathy and myelopathy
study of choice for evaluating herniated disk is?
MRI
In the cervical spines disk herniations occur most frequently at what levels?
C4-C5, C5, C6 and C6-C7
Majority of disk herniation occur at what levels?
at the lower three lumbar disk levels, L3-L4, L4-L5, L5-S1
What will lead to disk material bulging?
- Degeneration of the outer annular fibers of the disk or
2. trauma that leads to an interruption in those fibers
What study is useful in differentiating persistent or recurrent disk herniation from scar formation?
gadolinium-enhanced MRI studies of the spine
when the annular fibers rupture, the nucelus pulposus may herniate (usually _____ /direction) through ______.
when the annular fibers rupture, the nucelus pulposus may herniate (usually posterolaterally) through weakend area of the posterior longitudinal ligament. .
Degenerative disk disease leads to
progressive loss of the height of the intervertebral disk space
what is vacuum-disk phemoneon?
It is a late sign of degenerative disk.
Desiccation of the disk leads to release of nitrogen from tissue surrounding the disk resulting in the appereance of air density in the disk space.
How do degenerative disks look like on MRI
There is a decrease in water content of the nucleus pulposus that results in a lower signal intensity of the disk on T2 weighted images
How does degenerative disk disease look on conventional radiographs?
There is disk space narrowing and also changes in the vertebral bodies themselves.
Endplates of contiguous vertebral bodies become eburnated or sclerotic
- there is degeneration of outer annulus fibrosus which leads to the production of larger marginal osteophytes
Osteophytes at the uncovertebral joints are frequently associated with both ___ and ___
degenerative disk disease and osteophytes of the facet joints
What two diseases frequently occur together?
degenerative disk disease and facet arthritis
Facet arthritis is easier to visualize on ___ and actual nerve compression is easier to visualize on ___.
Facet arthritis - CT
nerve compression - MRI
DISH usually affects __ over the age of __
men; 50
DISH can occur anywhere in the spine, bu most often affects the ____
lower thoracis and/or lower cervical spine
what imaging would we use to diagnose DISH
conventional radiographs
how is DISH manifested
DISH is manifested by thick bridging or flowing calcification/ossification of the anterior or posterior longitudinal ligaments.
Compression fractures are sometimes first noticed because of ______ or ______
kyphosis or loss of overall body height
the study of choice for compression fractures of spine is
conventional radiograph
Osteoporotic compression fractures usually involve ___ and ___ aspects of the vertebral bodies.
anterior and superior aspects; they spare posterior body
what is wedge-shaped deformity
compression pattern (result of difference in height between anterior and posterior apsects in excess of 3mm) that leads to accentuation of the normal hyphosis in the thoracic spine
what is spinal stenosis
spinal stenosis refers to narrowing of the spinal canal or the neural foramina secondary to soft-tissue or bony abnormalities
what are soft-tissue abnomralities that can lead to spinal stenosis
hyperthrophy of ligamentum flavum, bulging disk(s) and OPLL
what are bony abnormalities that can lead to spinal stenosis
congenitally narrow spinal canal, osteophytes, facet osteoarthirtis , spondylolisthesis
at what regions is spinal stenosis most common
in the cervical and lumbar areas
what is neurogenic claudication
intermittent pain and paresthesias radiating down the leg worsend by standing or walking and relieved by flexing the spine or y lying supine or squatting
what is the study of choice for spinal stenosis
MRI
Where are bone metastases to be expected
Because of the rich blood supply in the posterior portion of vertebral bodies, hematogenous metastatic deposits to that part of the spine ar ecommon, expecially from lung and breast carcinoma.
In the spine, metastases may lead to ___ (type of fracture)
compression fractures
Multiple myeloma (most common primary malignancy of the bone) produce what type of lesion?
almost totally lytic lesions
One of the hallmarks of multiple myeloma is ____, so that myeloma may be associated with ____ and ____.
osteoporosis
associated with diffuse spinal osteoporosis and multiple compression fractures.
What is the screening study of choice for the detection of spinal metastases?
Tc-99m
neoplastic infiltration on T1 and T2 imaging
With neoplastic infiltration of the bone marrow, there is a decrease in the normally high signal of the vertebra on T1 weighted images and there is usually a high signal on T2 images.
What is diskitis?
Diskitis is an infection of the disk and is almost always associated with osteomyelitis of the adjecent vertebrae.
- it almost always spreads hematogenously from infection in another organ
PResenting symptoms of diskitis.
back pain and tenderness
What is ankylosing spondylitis
a chronic and progressive arthritis characterized by inflammation and eventual fusion of the sacroiliac joints
what is the hallmark of ankylosing spondylitis
sacroilitis
What is syndesmophyte
in ankylosing spondylitis, in the spine, there is ossification of the outer fibers of the annulus fibrosis producing thin bony bridges joining the corners of one vertebra to another, acelled syndesmophytes
what is bamboo-spine
progressive syndesmophyte production connecting adjacent certebral bodies produces a bamboo-spine
