What are the indications for MRI & CT: Disc lesions Post-operative spine(after surgery) Tumors Any degenerative disease Trauma Congenital abnormalities of the spine  

Preparations for CT & MRI: 1-Fasting for 4-6 hours 2-Contrast material Urographin ,telebrix 1-2 mg/kg Administration of contrast: Yes: In post-operative lumbar spine, inflammatory disorders& neoplastic lesions. No: disc lesions, trauma. Anesthesia Used with children & uncooperative patients.

Patient position: Is usually supine, sometimes side lying, & rarely prone.   How to see: Scanogram: primitive picture to detect the site of lumbar spine  

CT screening: Computed tomography (CT): . Axial slides 2-4 mm. . Usual scanning. . Axial slides 2-4 mm. 2 mm in cervical spine / 4 mm in lumbar spine Has bone & soft tissue window.  CT screening: . Whole segment of the spine 5 mm in cervical spine, 8 mm in lumbar spine. . Selective Scanning Every 3 mm especially in trauma, also in cervical disc lesions.  N.B: If I want to see one vertebra e.g. L3 I have to take 1 vertebra above (L2 )& 1 below (L4).

Soft tissue & bone window. CT Myelography: Is considered as intrathecal contrast injection with L- puncture needle. We have 2 windows Soft tissue & bone window. What are the structures I should evaluate in CT of lumbar spine: Lumbar spinal canal diameter normally 13 mm. Disc lesions. Others. facet, sacroiliac joints & paravertebral soft tissue.

Soft &bone window (CT) Lumbar

1. Lumbar spinal canal diameter: Spinal canal is bony structure, so we see it in bone window. The spinal canal must be closed (at the level of pedicles). We measure the AP diameter.  Types of canal stenosis: 1-Relative: 11-12 mm & this doesn’t need operation but it needs operation if there’s disc. 2- Absolute: 8 -10 mm & it must be operated.  

Disc lesions: We detect it in soft tissue window. Posterior border of the disc is more important as it has relation to the disc. The normal posterior border of the disc is CONCAVE. The abnormal is STRAIGHT OR CONVEX.

N.B: . Normally due to overload ,the disc of L5-S1 is CONVEX & the abnormal is also convex, so to judge if it’s normal or no look at the next slide if: the posterior border of the disc is convex so it is ABNORMAL. . The angle of inclination in L5-S1 is more than 30 & the device accept up till 30 only so part of the slide will contain bone & part will contain disc.

Normal CT Lumbar

Disc bulge(CT axial)

MRI – LUMBAR SPINEM NERVE ROOTS FORAMEN AXIAL VIEW

Manifestations of arthritis in any joint:  (Spondylosis in spine and osteoarthritis of other joints) Osteophytic lipping. Narrow joint space. Subarticular bone sclerosis Sub cortical pseudo cystic changes. Intra articular air.(vaccum phenomena)

Vacuum phenomena

CT of cervical spine

We have 2 types of joints: Neurocentral joint: Is the articulation between one vertebra above & one vertebra below which makes the shape of the body of the vertebral end plate . Facet joint: Is the articulation between the inferior lip of the transverse process of one vertebra above with the superior lip of the transverse process of the vertebra below, it’s called Hamburger’s Sandwich.  Arthritis of the neurocentral or facet joint gives the same manifestations of nerve compression due to disc lesion.

Cervical disc in CT: We see it in soft tissue window .The disc in cervical spine is very narrow so every slide will contain both disc & bone, therefore there isn’t a slide of pure disc, So we choose the slide which contain more disc for assessment. . All posterior edges of cervical spine are normally convex. . See if there’s disc substance protruded than the bone. . Normal spinal cord picture is kidney shaped.  

Difference between cervical & lumbar spine in CT Item Cervical Lumbar Slide Width 2 mm 4mm Neurocentral joint Present Absent Spinal canal diameter No diameters, but assessed by vision  the spinal cord is kidney shaped & surrounded by C.S.F. 13 mm Posterior edge of disc Is usually convex All lumbar discs are concave except L5-S1 is normally convex or flat.

HNP with nn root impingement HNP with nn root impingement. Sx radicular (radiating) pain down extremity. Signs= hyporeflexia, weakness, atrophy.

HNP without nerve root impingement HNP without nerve root impingement. Sx localized back pain since disc has pain fibers.

Bulging (Herniated) Disc can cause Radiculalgia (pain down arm/leg), Radiculopathy (weakness, atrophy, hyporeflexia).

Stages of disc pathology (4 stages) Intervertebral Disc Diagnoses: Degenerative Disc Disease (Pre-Existing) Prolapse = Herniated Extruded/Sequestered Require Surgery

CT of the spine

CT axial bone& soft tissue widow

CT machine

MRI CT plain x-Ray

C2-3 INTERVERTEBRAL DISC CT– CERVICAL SPINE C2-3 INTERVERTEBRAL DISC FORAMEN DISC FORAMEN FACET JOINT FACET JOINT SPINOUS PROCESS AXIAL SAGITTAL

CT- CERVICAL SPINE C-1 SECTION ARCH OF C-1 DENS BASE OF SKULL MASTOID AXIAL SAGITTAL

CT- LUMBAR SPINE POST MYELOGRAM DISC SPINOUS PROCESS

CT– CERVICAL SPINE C- 3 SECTION PEDICLE PEDICLE LAMINA AXIAL SAGITTAL

CT-- CERVICAL SPINE C-2 SECTION C-2 BODY DEGENERATED C6-7 C-2 SPINOUS PROCESS AXIAL SAGITTAL

CT axial CT sagittal

CT- LUMBAR SPINE POST MYELOGRAM Axial PEDICLE PEDICLE NERVE ROOTS

Posterior arch #(CT)

Burst # (CT) axial

sagittal CT

CT axial section (base of the skull)

CT- LUMBAR SPINE POST MYELOGRAM FORAMEN FORAMEN

CT of cervical spine(sagittal)

CT axial

CT of cervical spine (axial)

CT sagittal

CT sagittal tear drop # dislocation Tear drop # dislocation(plain)

CT-LUMBAR SPINE POST MYELOGRAM THECAL SAC LAMINA LAMINA

CT- LUMBAR SPINE POST MYELOGRAM FACET JOINTS

CT- LUMBAR SPINE POST MYELOGRAM PEDICLE PEDICLE NERVE ROOTS