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RadioLoGY

lecture

جامعة بغداد

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كلية الطب

SPINE

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م بتكم

MUSTAFA laith

Dr Laith

Spine

Radiology 15

Prof Laith

Spine

 MRI is the imaging modality of choice for detection of spinal

pathology

 X ray is still important particularly in spinal trauma.The intervertebral

discs appear radiolucent on X ray

 CT is useful in detection of the site of fracture & presence of

intraspinal bone fragment or detection of the presence of foreign
bodies (particularly if metallic )where MRI is contraindicated

 Radionuclide bone scan may be used in case of suspected spinal

metastases

 On MRI T1 weighted image , the fat within the bone marrow of the

vertebral body appears bright while the CSF & intervertebral discs
appear of low signal .On T2 sequence the CSF & intervertebral disc
appear bright

SIGNS OF ABNORMALITY

Disc space narrowing

1-the  discs  spaces  are  normally  of  the  same  height  at  all  levels  in  the
cervical & thoracic spine ,  in the lumbar spines the disc spaces increase
slightly in height going  down the spine  except for the  disc space at  the
lumbosacral junction which is usually narrower than the disc above it
2-MRI  on  sagittal  section  clearly  shows  the  height  of  the  disc  &  any
alteration in the signal intensity suggesting pathology
3- Narrowing of the disc space occurs in degenerative disease & in disc
infection

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Radiology 15

Prof Laith

Collapse of the vertebral body

Collapse is loss of height of vertebral body best appreciated on lateral
plain X ray & sagittal MRI section .The causes of collapse are:

a) Metastases & myeloma: bone destruction or replacement of the

normal signal of the bone marrow is well appreciated on MRI. The
pedicle may be destroyed with metastases but the disc space is
usually normal

b) Infection :the disc space is usually narrowed or obliterated , with

destruction of the adjacent bone next to the affescted disc but the
pedicles usually intact .Alteration of the signal intensity of the disc
& the vertebral body due to inflammatory oedema seen on MRI

c) Osteoporosis & osteomalacia: generalized reduction in bone

density  , normal or slight increase in the height of the disc space ,
intact  pedicles  &  normal  signal  intensity  of  the  vertebral  body  on
MRI

d) Trauma: compression fracture of the vertebral body occurs due to

forward flexion of the spine causing wedging of the vertebral body.
The  superior  surface  is  usually  concave  ,  the  discs  are  normal  or
may be impacted in into the fractured bone, associated fractures of
the  pedicle  &  neural  arch  may  be  seen  but  otherwise  the  bone  &
disc signal intensity are normal

e) Eosinophilic granuloma: complete collapse of one or more of the

vertebral bodies in children or young adults with Langerhan`s
histiocytosis .Flattening of the vertebral body resulting in vertebra
plana. Normal pedicles & adjacent disc spaces seen

Pedicles abnormality

1- On plain film the pedicles are best assessed on the frontal view except

in the cervical spine where the oblique view is necessary

2- Destruction of one or more pedicle is fairly reliable sign of metastases

Spine

Radiology 15

Prof Laith

3- Flattening & widening of the distance between the two pedicles

occurs with tumors arising within the spinal canal e.g. meningioma or
neurofibroma

Dense vertebra

1- this sign is seen on X ray & CT
2- single or multiple vertebrae are affected
3- Common causes are :

a) Metastases : from breast or prostate carcinoma
b) Malignant lymphoma
c) Paget`s disease : increase in overall size of the veretbra in this

condition help to make differentiation from metastases , in addition
there is coarse trabeculation

d) Haemangioma : gives characteristic vertical striation in a vertebra

that is of normal size

Lysis within vertebra

1- seen on X ray or CT scan

2- commonest causes

a) Metastases : from bronchus , kidney
b) Multiple myeloma
c) Malignant lymphoma (occasionally )
d) Infection : lysis involve one or two adjacent vertebral bodies &

adjacent disc space is almost invariably narrowed

Paravertebral shadow

1- Easily appreciated on MRI & CT
2- The thoracic spine is the easiest site to recognize such swelling on

plain film as they assume a characteristic fusiform

3- Swelling in the lumbar region have to be very large if they are to

displace the psoas outlines & be recognized on the plain film

Spine

Radiology 15

Prof Laith

4- Anterior swelling in the cervical region can be recognized by forward

displacement of the parapharyngeal air shadow

5- Paravertebral soft tissue swelling occur with infection , malignant

neoplasm & hematoma following trauma .Specific diagnostic signs
often present in such cases in the adjacent bones

METASTASES /MYELOMA

 MRI is the most accurate test for demonstrating metastases ,

myeloma or lymphoma .The tumor appear hypointense on T1,
hyperintense on T2 with variable enhancement after contrast injection

 Metastases are shown as areas of lysis , sclerosis or mixed on plain

film often with involvement of the pedicle .Collapse of one or more
vertebra may occur

 Myeloma shown as well defined lytic areas in the vertebral bodies ,

the pedicle is often not involved .Collapse of the vertebra is particular
feature in MM

 The intervertebral disc is usually preserved in both metastases & MM

INFECTION

 The common infecting organism are M. tuberculosis & S. aureus
 The hall mark of the condition is destruction of the intervertebral disc

& adjacent vertebral bodies

 Early stage: narrowing of the disc space & erosion of the adjoining

surface of the vertebral bodies

 Later bone destruction occurs , sometimes causing collapse with sharp

angulation known as the gibbus

 Paravertebral abscess usually present
 In Tuberculous spondylitis the lesion is purely lytic with large

paravertebral shadow that may calcify eventually

Spine

Radiology 15

Prof Laith

 In pyogenic infection bone destruction & sclerosis occur with small

paravertebral shadows

 Bony ankylosis (fusion of the vertebral body across the obliterated

disc space ) occurs with healing

 CT shows the bone destruction & paravertebral shadows to best

advantage

 MRI shows the disc space narrowing alteration in signal intensity of

the spine & presence of paravertebral shadow

 FNA or needle biopsy used to identify the infecting organism

SPINAL TRAUMA

 Plain film is the initial investigation in trauma to the spine , points to

be assessed are : (a) fracture of the vertebral bodies , pedicles , lamina
& spinous processes (b)alignment of the fractures (c) alignment of the
articular facets & vertebral bodies

 The spine is divided in three columns on the lateral view : (1)anterior

column (injuries are considered stable as they do not endanger the
spinal cord ), middle & posterior (unstable injuries )

 CT is very helpful in major trauma to the spine as it shows fractures

of  the  posterior  elements,  dislocation  resulting  in  unstable  spine  ,
bone fragments displaced in the spinal canal (burst fracture )that may
need  surgical  removal  .The  disadvantage  is  that    CT    is  inferior  to
MRI in showing the state of spinal cord

 MRI is excellent in showing the hemorrhage & contusion of the

spinal cord in these patients

Spine

Radiology 15

Prof Laith

Degenerative Disc Disease (Spondylosis)

 Definition: degeneration of the intervertebral disc .It occurs

maximally in the lower cervical & lower lumbar spines

 The degenerate disc may herniated into the surrounding tissue , may

press on the nerve roots or spinal cord resulting in pain &/or
neurological deficit

 The degenerate disc stimulate the formation of osteophytes which

together with thickening of the soft tissue may press upon the spinal
cord or nerve roots, the image is further complicated by OA changes
affecting the apophyseal joints

Plain Radiograph in Spondylosis

 There is poor correlation between plain radiograph findings & the

severity of symptoms or neurological deficit .The aim of requesting
plain radiograph is to exclude other disease processes

 Signs of spondylosis : a)disc space narrowing, b)sclerosis &

osteophytes  formation  at  the  adjoining  surfaces  of  the  vertebral
bodies  .Osteophytes  at  the  posterior  aspect  of  the  vertebral  body
narrow  the  spinal  canal  &  may    encroach  on  the  exit  foramina
resulting in compression of the nerve roots .In  the cervical spine the
oblique view is the best to shows osteophytes near the exit foramen

 Schmorl`s nodes are indentations into the end plates of the vertebral

bodies due to protrusion of the disc material , these are not part of
disc degeneration & are of no clinical significance

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Radiology 15

Prof Laith

MRI In Spondylosis

 Degeneration of the disc seen as loss of normal signal intensity on T2

sequence due to dehydration , the disc later lose height & may bulge

 Facet joint arthropathy :this is another feature of degenerative spinal

disease .Inflammation of the joint results in joint hypertrophy & may
cause compression of the nerve roots at the exit foramina

 Osteophytes pressing on the cord in cervical region can result in

ischemic changes & eventually cord atrophy , this best shown on
sagittal T2 weighted sequence

 End plate changes :a)type I : early , low signal on T1 , high signal on

T2  from  vascularized  fibrous  tissue  ,  b)type  II  :  high  signal  on  T1  ,
isointense on T2 from local fatty replacement of the marrow  & c)type
III in advanced stage , low SI on both T1 & T2 due to sclerosis

MRI In Disc Herniation

 Disc protrusion can vary from small central bulge of little clinical

significance to larger posterolateral or far lateral herniation of disc
material .The herniated disc can migrate a considerable distance &
may become detached from the parent disc (sequestrated disc )

 The commonest sites for disc herniation are the three lower cervical

discs & lower lumbar discs

 MRI in sagittal section with selective axial sections on the levels of

interest can clearly show the state of disc & spinal cord

 One third of demonstrable disc herniation is asymptomatic , therefore

the criteria for surgery should be clear cut evidence of compression
of the clinically affected nerve root

 Cervical disc herniation can press on the nerve root sheath or may

compress  the  spinal  cord  .These  changes  can  be  aggravated  by
hypertrophy  of  the  spinal  ligaments  ,  facet  joint  arthritis  &
osteophytes formation

Spine

Radiology 15

Prof Laith

 Lumbar disc herniation occurs most commonly at the levels L4-5,

L5-S1.They  are  directly  visualized  as  small  focal  projections  that
points  towards  the  neural  foramen  .Loss  of  visualization  of  the  fat
surrounding the nerve root sheath is helpful indication of nerve root
compression

 MRI is useful for patients who continued to have symptoms after

surgery for disc herniation .Post operative scarring shows higher
signal in comparison to recurrent disc & shows enhancement after
contrast in contrast to recurrent disc

CT In Disc Herniation

 CT for disc herniation has been largely replaced by MRI
 On CT the disc is of lower density than the adjacent bone , the

content  of  the  dural    sac  are  all  of  the  same  density  .The  nerve  root
sheath  are  seen  as  circular  dots  adjacent  to  the  dural  sac  surrounded
by fat within the spinal canal

Spinal Stenosis

 congenital spinal stenosis can give rise to cord or nerve roots

compression especially when spondylotic changes supervene

 MRI is the ideal method to show the shape & size of the spine

Ankylosing Spondylitis



The sacroiliac joints & the spine are principally affected



Sacroiliac joints involvement precede the spine



The earliest radiological sign is fuzziness of the SI joint margin

which progress to frank erosion & later obliteration of the joint space

Spine

Radiology 15

Prof Laith



The spinal ligaments ossify forming vertically oriented bony bridges

between  the  vertebral  bodied  .The  apophyseal  joints  &
costotransverse  joints  become  fused  .In  advance  stage  the  whole
spine becomes a solid block of bone forming what is called bamboo
spine

Spina Bifida

 Incomplete closure of the vertebra canal usually in the lumbosascral

region , may be associated with protrusion of the spinal cord
(meningomyelocele ) or its membranes (meningocele).

 There is absent of the lamina of several vertebra with increased

interpedicular distance

 CT& MRI are useful to verify the condition & to assess any

associated abnormalities

 US can provide antenatal diagnosis
 Spina bifida occulta is a condition in which no external abnormality is

present & no neurological deficit but failure of the two laminae to
fuse , this occur at any level commonly the lumbosacral region

Spondylolisthesis

 Definition : forward slipping of the one vertebral body over the one

below it , occurring most commonly at the lumbosacral junction &
between L4 & L5 vertebral bodies

 Cause : defect at the pars interarticularis (junction of the superior &

inferior articular facet of the same vertebra ) secondary to stress
fracture

 Minor slipping can occur without defect in the pars interarticularis if

there is degenerative disc disease with osteoarthritis of the
apophyseal joints

 Oblique & lateral views are used to visualize the defect

Spine

Radiology 15

Prof Laith

 Radionuclide scanning shows increase uptake at the site of defect

before X ray abnormality is seen

 Spondylolysis : defect of the pars interarticularis without slipping

Spinal Cord Compression

MRI is the modality of choice to show the cause, level & extent of spinal
cord compression

 Causes :

1. extradural lesions : metastases , spinal tuberculosis , cervical

disc  herniation  (lumbar  discs  are  too  low  to  compress  the
spinal  cord  ),  bone  &    soft  tissue  reactions  that  accompany
spondylosis

2. intradural extramedullary lesions i.e. lesions within the dura

but outside the spinal cord as neurofibroma or meningioma

3. intramedullary lesions as spinal cord tumors or hemorrhage

into the spinal cord

Intrinsic Disorders of the Spinal Cord

MRI  is  excellent  in  demonstrating  conditions  that  expand  the  cord  e.g.
syringomyelia  ,  hematoma  ,  tumors  or  those  condition  that  do  not  cause
expansion as demyelination plaque of multiple sclerosis

 Contrast enhanced MRI is required in multiple sclerosis to assess the

activity of the disease as enhancement indicates currently active
disease

End of Lecture 15