Lecture

MRI Spine

Bone marrow changes:

1 -Type I: edema2 -Type II: fatty ( white in T1)

3 -Type III: bone sclerosis (like bone cortex black in T1 & T2)

Degenerative marrow changes:If bony end plate is white in T1 fatty [as it 's not seen in T2]If bony end plate is black sclerosis

1- edema : due to compression by disc (ant) & ligamentum flava (post)

2- early myelomalacia : reversible if edema is treated3- late myelomalacia : irreversible if edema isn't treated

N.B.Both early & late myelomalacia produce focal area (white

stain) of low signal in T1 & high signal in T2 so we differentiate by clinical pressure, by history & duration of illness

If it's recent edemaNot so far early myelomalaciaFar late myelomalaciaIf there is local lesion in spinal cord without compression

another pathology

Paravertebral soft tissue shadows

.Hemorrhage, bone fragments

.Abcesses( inflammatory disorders)

.Tumor (neoplastic extra osseous mass)

Contrast administration ;DTPA

o We use it to differentiate between postoperative

scar tissue & residual or recurrent disc lesions

o If it gains dye (becomes white in colour) scar

tissue

o If it doesn't gain dye disc lesion

o If part gains dye & part doesn't gain so there's

both disc & scar tissue

o We use it to differentiate between postoperative

scar tissue & residual or recurrent disc lesions

o If it gains dye (becomes white in colour) scar

tissue

o If it doesn't gain dye disc lesion

o If part gains dye & part doesn't gain so there's

both disc & scar tissue

Indications of contrastIndications of contrast

1 -To detect site of operation

2 -To detect degree of thecal

decompression

3 -To detect post operative complications

•Post operative cervical surgery: There's no contrast administration in cervical spine

as the aggressiveness of scar tissue formation in cervical spine is not as in lumbar spine after.surgical interference

.N.B Contrast administration from 2 month to 20 years

& not after that as scar tissue becomes mature.contrast doesn't appear

•Post operative cervical surgery:There's no contrast administration in cervical spine

as the aggressiveness of scar tissue formation in cervical spine is not as in lumbar spine after surgical interference.

N.B.Contrast administration from 2 month to 20 years

not after that as scar tissue becomes mature & contrast doesn't appear.

Types of surgery

1- spinolaminectomy

2-hemi laminectomy

(pore in the lamina & suction of the disc)

3-laminar fenestration minimally invasive ( the

lamina of the above vertebra which is removed)

Post operative complications:

1 - Scar tissue / disc lesions (scar tissue(enhances

2 -Disc space infection3 - Arachnoiditis (adhesion between cauda

(equina nerve rootsN.B.

Perineural scar: scar formation around rootswhich become compressed 

1 -Scar tissue / disc lesions (scar tissue enhances)

2 -Disc space infection3 -Arachnoiditis (adhesion between cauda

equina nerve roots)N.B.

Perineural scar: scar formation around roots which become compressed 

Differential diagnosis between nerve root & recurrent disc:

After contrast administration if we see a black point on one side look at the contra lateral side

if there's also another black point so this is a nerve root

&if there's not present so this is recurrent discN.B.

Usually the nerve root at site of scar tissue is thick due to compression which leads to swelling

Arachnoiditis:It's diagnosed in axial T2 image never to be diagnosed in

sagittal image As nerve roots are black & C.S.F. is whitePseudo cord sign:All nerve roots become adhesive to each other & appear

as a cord in the cauda equine level (after L1-L2)Empty thecal sac sign:Nerve roots become attached at the edges of the thecal

sacDisc space infection:Hyperemia, fluid, pus, edges of the vertebrae are filled with water In T2

appears white & in T1 appears black

Comparison between degenerated disc and disc space infection

Degenerated disc Disc space infection

. Disc is black in T1& T2

. Presence of osteophytes with bone marrow changes.

disc is white in T2 but black in T1

. sclerotic only