MRI Spinal Column

Cervical Spine

The cervical spine shows a normal degree of lordosis with normal width of the bony spinal canal.

The vertebral bodies are normal in their number, shape, and interrelationships.

The atlantodental distance is normal. The articulating vertebral end plates present smooth margins. The intervertebral disk spaces are of normal height.

The intervertebral disks do not project past the posterior surface of the vertebral bodies in any imaged segment.

The spinal cord, including the craniocervical junction, displays normal position, configuration, width, and internal structure. The bone marrow of the vertebral bodies appears normal.

The prevertebral and paravertebral soft tissues show no abnormalities. Interpretation

The cervical spine appears normal.

Checklist

Position

Bony spinal canal

Vertebral bodies

Normal cervical lordosis (no hypolordosis or hy-

perlordosis, no kyphotic deformity)

No segmental malalignment

Normal position of the dens (see below)

Width (see below)

Smooth margins

Number (seven)

Shape (square except for the dens) Position (straight alignment of posterior margins, no steps) End plates

— Continuous margins (no discontinuities)

— Smooth contours

— No circumscribed depression

— No marginal osteophytes

Intervertebral disk space

Spinal cord

Nerve roots

Neuroforamina

Facet joints

Spinous processes

Soft tissues

Width (see below)

Normal signal characteristics: moderate to slightly hyperintense T2-weighted intensity (not hypointense to other disks) No disk protrusion past posterior surface of adjacent vertebral bodies Configuration Width

Signal characteristics

No circumscribed change in signal intensity No circumscribed narrowing or expansion Course

Passage through the neuroforamina Dural tube:

— No circumscribed narrowing or expansion

— Perimedullary contents of fluid signal intensity

Configuration Width

No hypertrophy of uncovertebral joints

Shape

Position

Contours (smooth, continuous)

No hypertrophy

Vertebral arches intact

No shortening of pedicles

Shape

Position

Size

Bony structure

Fat-equivalent signal intensity of bone marrow No circumscribed hypointense or hyperintense areas

Symmetrically arranged on both sides of the vertebral bodies and spinous processes No masses

Prevertebral soft-tissue structures (especially the pharynx and thyroid gland; no masses)

Important Data

1

Atlantodental distance:

a Sagittal plane: approx. 1-3 mm (up to 5 mm in children)

b Coronal and axial planes: dens is centered

2

Craniovertebral angle (angle formed by the basilar line and

the posterior tangent to C2):

• Normal range of 150° (flexion) to 180° (extension) (spinal

compression occurs at less than 150°)

3

Chamberlain's line (line connecting the posterior border of

the hard palate with the posterior rim of the foramen

magnum):

• Tip of the dens should project no more than 1 mm ±

6.6 mm above the line

4

Retropharyngeal space:

• Up to 7 mm (at level of C2)

5

Width of spinal cord:

• Sagittal > 6-7 mm

6

Sagittal diameter:

• C1 > 21 mm

• C2 > 20 mm

• C3 > 17 mm

• C4-C7 = 14 mm

7

Height of intervertebral disk spaces:

• C2<C3<C4<C5<C6 > C7

8

Retrotracheal space:

• Up to 22 mm (at level of C6)

9

Anteroposterior diameter of preodontoid space:

• <2 mm

10

Width of spinal canal:

• Transverse diameter at level of pedicles > 20-21 mm

T2-weighted midsagittal image
T2-weighted sagittal image
1b

Coronal image

Coronal image

Axia! image at the !eve! of the dens
Axial image at the level of the dens
Axial image at the level of the laminae

Thoracic Spine

The thoracic spine shows a normal degree of kyphosis with a normal width of the bony spinal canal.

The vertebral bodies are normal in their number, shape, and interrelationships. The articulating vertebral end plates present smooth margins. The intervertebral disk spaces are of normal height, and the disks do not project past the posterior surface of the vertebral bodies in any segment.

The spinal cord displays normal course, configuration, width, and internal structure.

The bone marrow of the vertebral bodies appears normal.

The prevertebral and paravertebral soft tissues show no abnormalities.

Interpretation

The thoracic spine appears normal.

Checklist

Position

Bony spinal canal

Vertebral bodies

Intervertebral disk space

Spinal cord

Thoracic kyphosis (see below) No segmental malalignment Width (see below) Smooth margins Number (12) Shape (square)

Position (straight alignment of posterior margins, no step) End plates

— Continuous margins

— No circumscribed depression

— Smooth contours, no marginal osteophytes Width (see below)

Normal signal characteristics: moderate to slightly hyperintense T2-weighted signal intensity (not hypointense to other disks); "nuclear cleft" signifies an adult disk No disk protrusion past posterior surface of adjacent vertebral bodies Configuration Width

Signal characteristics

Nerve roots Dural sack

Neuroforamina Facet joints

Spinous processes

Soft tissues

Aorta

No circumscribed signal changes

No circumscribed narrowing or expansion

Course

Passage through the neuroforamina

Shape

Width

No circumscribed narrowing or expansion

Contents of fluid intensity

Configuration

Width

Shape

Position

Contours (smooth, continuous)

No hypertrophy

Vertebral arches intact

Pars interarticularis intact

No cleft anomalies

No shortening of pedicles

Shape

Position

Size

Bony structure

Fat-equivalent signal intensity of bone marrow No circumscribed hypointense or hyperintense areas

Symmetrically arranged on both sides of the vertebral bodies and spinous processes No masses

Prevertebral soft-tissue structures

Important Data

1 Kyphotic angle (of Stagnara):

• Angle formed by a line parallel to the vertebral end plates of T3 and T11 = 25°

Width of spinal canal:

2 Transverse diameter at level of pedicles:

3 Sagittal diameter:

4 Width of intervertebral disk spaces:

T2-weighted midsagittal image
Axial image at the level of the laminae
Coronal image

Lumbar Spine

The lumbar spine shows a smooth lordotic curve with a normal promontory angle. The bony spinal canal displays normal width. The vertebral bodies are normal in their number, shape, and interrelationships. The articulating vertebral end plates present smooth margins. The intervertebral disk spaces are of normal height, and the disks do not project past the posterior surface of the vertebral bodies in any segment.

The conus medullaris terminates normally at the L1 level and divides into its filaments.

The dural tube appears normal in its lumbar portion and evaluable sacral portion.

The bone marrow of the vertebral bodies appears normal. The imaged soft tissues show no abnormalities.

Interpretation

The lumbar spine appears normal.

Checklist

Position

Bony spinal canal

Vertebral bodies

Intervertebral disk space

Lumbar lordosis (see below) Lumbosacral angle (see below) No segmental malalignment Width (see below) Smooth margins Number (five) Shape (square)

Position (straight alignment of posterior margins, no step) End plates

— Continuous margins

— No circumscribed depression

— Smooth contours

— No marginal osteophytes Width (see below)

Normal signal characteristics: moderate to slightly hyperintense T2-weighted signal intensity (not hypointense to other disks); "nuclear cleft" signifies an adult disk

Conus medullaris

Nerve roots

Bony portions of vertebral bodies

No disk protrusion past posterior surface of adjacent vertebral bodies (posterior disk contours on axial images: concave at L1-L4, straight at L4/5, slightly convex at L5/S1) Configuration Width

No circumscribed narrowing or expansion Position (terminates at approximately the L1 level)

Normal division into filaments Signal characteristics Filaments:

— Course (sweeping, not straight; no posterior adhesions)

— No circumscribed mass Course

Passage through neuroforamina Dural sac:

— No circumscribed narrowing or expansion

— Contents of fluid intensity Neuroforamina:

— Configuration

— Contours (smooth, continuous)

— No hypertrophy of facet joints Vertebral arches intact

Pars interarticularis intact No cleft anomalies

— No shortening of pedicles

— Spinous processes:

— Bony structure

Fat-equivalent signal intensity of bone marrow

— No circumscribed hypointense or hyper-intense areas

Soft tissues

Aorta, iliac vessels

Symmetrically arranged on both sides of the vertebral bodies and spinous processes Prevertebral soft-tissue structures No masses

Important Data

1

Width of intervertebral disk space and height of lumbar in

tervertebral disks:

• 8-12 mm

• Increases from L1 to L4/5

• Usually decreases at L5/S1, but may be the same as or

greater than L4/5

2

Lordosis (static axis):

• Plumb line from center of L3 should intersect S1

3

Lumbosacral angle (Sl/horizontal plane) = 26-57°

4

Width of spinal canal: sagittal diameter:

• 16-18 mm (simple formula: not less than 15 mm; 11-

15 mm = relative stenosis, less than 10 mm = absolute ste-

nosis)

S

Width of spinal canal: transverse diameter (at level of

pedicles):

• L1-L4: >20-21 mm

• L5: >24 mm

S Jones-Thomson ratio (= AxB/CxD):

• Between 1/2 and 1/4.5 = normal (denominator > 4.5 = spinal

stenosis)

7

Lateral recess (sagittal diameter):

• > 4-5 mm

8

Ligamenta flava:

• Width < 6 mm

T2-weighted axial image at level of pars interarticularis
T1-weighted axial image at level of neuroforamina
Coronal image

Sacroiliac Joints

The sacroiliac joints are normally shaped with normal development of the sacrum and iliac wings and a normal-appearing lumbosacral junction. The joint space is of normal width on both sides. The joint contours are smooth and sharply defined.

The subchondral bone marrow appears normal. There are no marginal osteophytes.

The sacrum and iliac wings also contain normal bone marrow and present smooth, intact cortical boundaries. The sacral neuroforamina are of normal width.

The nerve filaments shows a normal course and diameter, and the width of the sacral spinal canal is normal.

The muscles and the imaged organs of the lesser pelvis show no abnormalities.

Interpretation

The sacroiliac joints appear normal.

Checklist

— Articular surfaces converge posteriorly

— Bilateral symmetry

— Cortical thickness (uniform)

— No steps or discontinuities

— No marginal osteophytes

— Uniform normal width (see below)

— No circumscribed narrowing or expansion

— No obliteration (ankylosis)

— No unilateral increase in joint fluid

— No signal voids within the joint space (air, calcifications)

— No marginal osteophytes (caution: the ileum normally contains areas of hyperostosis)

— Normal thickness of articular cartilage (see below)

— No abnormal contrast enhancement

— No thickening of joint capsule

• Subchondral region:

— Homogeneous, fat-equivalent signal intensity of bone marrow

— No erosive or destructive changes

— No increase in T2-weighted signal intensity (e.g., circumscribed due to cysts or patchy due to bone-marrow edema)

— No decrease in T1-weighted or T2-weighted signal intensity (e.g., sclerosis on the sacral side or fatty infiltration of the periarticular bone marrow)

Sacrum • Anatomy (four vertebral bodies, four neuro-

foramina)

• Symmetry (lateral sacral mass)

• Width and arrangement of neuroforamina

• Bone marrow signal (fat-equivalent, no marrow-replacing process)

• Dural tube (width, no circumscribed narrowing or expansion)

• Filaments have normal size and arrangement, and are not fused together; no posterior adhesions

• Sacral plexus (course, width) Iliac wings • Shape

• Cortical thickness (continuous and uniform; no steps or discontinuities)

• Bone marrow signal (fat-equivalent, no marrow-replacing process)

• Symphysis and femoral heads Lumbar spine • Position:

— Lumbar lordosis (sagittal survey image)

• Lumbosacral angle (see below)

• Vertebral bodies (shape, margins, bone-marrow signal)

• Height of intervertebral disk spaces

• Intervertebral disks

• Neuroforamina

— Origin and course

• Vertebral arches intact

• Spinous processes

• Coccyx (shape, structure, position—see below) Soft tissues • Muscles (especially the iliac, psoas, gluteals, and intrinsic back muscles)

• Fat and intra-abdominal structures (e.g., sigmoid colon and rectum, bladder, prostate or uterus and ovaries)

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