spine

1. HOW TO READ SPINE MRI
QM

3. BASIC
• T1 images weighted toward fat
• T2 images weighted toward water
• Dark on T1- and bright on T2-weighted images 
Water, cerebrospinal fluid, acute hemorrhage,
soft tissue tumors
• Other tissues showing similar intensity on both
T1- and T2-weighted images:
– Dark: cortical bone, rapid flowing blood, fibrous tissue
– Gray: muscle and hyaline cartilage
– Bright: fatty tissue, nerves, slow flowing
(venous)blood, bone marrow
Imaging and special studies, Miller review of orthopaedic

6. MID-SAGITAL
How do you tell
which sagittal
image represents
the true mid-
sagittal cut?
Simply scroll
through the
images until you
find the one that
has the largest
looking spinal
canal

7. PARA-SAGITAL
you start to see the
traversing nerve
roots show up (red
arrows)
the horizontal dimensions of
the vertebral canal get
progressively smaller. In fact,
once you hit the beginning of
the intervertebral foramen
(a.k.a. neuroforamen) zone
(as we will see below) you
can no longer see any
vertebral canal.

8. The parasagittal region is very important for
looking for potential pain generators. For
example, lumbar disc herniations typically
occur in the paracentral zone and are
visualized on para sagittal cuts.
Symptomatic facet joint cysts are also typically
found in the paracentral zone, only they are
found more posteriorly positioned as compared
to a disc herniation.

9. para-sagittal zone / lateral recess that
demonstrates a moderate-sized disc
herniation (red arrows)
If you look closely, you can also see the
herniation touching one of the traversing
nerve roots and even pushing it a little bit
off course (green arrow). This is sometimes
called "tenting."

10. FORAMINAL-SAGITAL
he foraminal-sagittal region, which is
typically represented by only one slice,
demonstrates some new anatomy that
includes the exiting nerve roots (and
sometimes even their accompanying blood
vessels).
Figure 4 is a foraminal-sagittal cut that
demonstrates the boundaries of the right
neural foramen (pink circle) quite nicely:
The roof and floor are created by the
pedicles (P) (the strongest part of the
vertebra) of the vertebra above and below,
respectively. The posterior boundary is
created by the superior articular process of
the vertebra below, and the anterior
boundary is created by the disc and
vertebral body (VB)

11. AXIAL

13. Figure 5 is a real disc-level T2-weighted axial MRI image in which I have outlined the
disc, (white) the thecal sac, (green) and the posterior arch (yellow). I have also
colored the left neural foramen red and marked the right side of the image.
*It is important to note that all MRI and CT axial images, whether they be on disk or
film, are reversed with regard to sidedness—anything on the right of the image is in
reality on the left. This is because we are really looking up from beneath the slice and
not down from above.

15. The Inspection Algorithm
1.Inspect the Disc
2.Inspect the Neural Foramina
and Thecal Sac
3.Inspect the Posterior Arch

16. Inspect the Disc
• Prominent/bulging?
Focal herniation?
• Central? Paracentral?
Far lateral?
• Annulus tear? 
hyperintensity

17. Inspect the Neural Foramina and
Thecal Sac
• Foramen open or stenosis?
• By what structure?
narrowed anteriorly by
osteoarthritic thickening of the
posterolateral vertebral body, by
a posterolateral disc herniation,
or by a bulging disc
narrowed posteriorly by
osteoarthritic thickening of the
superior articular process

18. Inspect the Neural Foramina and
Thecal Sac
Normally the thecal sac
should be symmetrically
shaped into a shield-like
configuration (figure 7)
with the lumbar nerve
roots visible and lined-up
along its periphery

19. Inspect the Posterior Arch
• Although CT is the gold
standard for detecting
fractures of the posterior
arch, sometimes they are
still visible on MRI.
• Therefore, carefully
inspect the posterior arch
for signs of cortical
disruption (breaks in the
outlines of the wishbone)

20. Quiz
• T1/T2?
• Disc/ bony Level?
• Disc? Prominent/bulg? Focal stenosis (central, paracentral,
far lateral)?
• Neural foraminal? Thecal sac? Narrowed anteriorly or
posteriorly? By what structure?
• Posterior arch? Lig flavum thickening? Fracture? Facet
conditions?

21. Quiz
• T1/T2?
• Disc/ bony Level?
• Disc?
• Neural foraminal? Thecal sac?
• Posterior arch?

22. Quiz
• T1/T2?
• Disc/ bony Level?
• Disc?
• Neural foraminal? Thecal sac?
• Posterior arch?

23. • It is a T1-weighted image. You should have
also noted that the posterior arch is abnormal.
Specifically, ligamentum flavum (LF) (which is
usually barely seen) has greatly hypertrophied
(second) and has compressed the
posterolateral corners of the thecal sac. so
what is this condition called? Central stenosis.

24. Quiz
• T1/T2?
• Disc/ bony Level?
• Disc?
• Neural foraminal? Thecal sac?
• Posterior arch? Lig flavum
thickening? Fracture? Slip of
facet joint?

25. • The presence of a fairly hyperintense (white)
flattened teepee-like defect in the disc
(remember, this should be black), which is
indicative of a massive bilateral annular tear
within the annulus

26. NEXT
…

27. The evaluation of an MRI study steps :
1. Determination of which conventional and specialized MRI pulse
sequences are available for review
2. Evaluation of T2-weighted images for recognition of areas of
increased T2-weighted signal that are not expected or physiologic
3. Evaluation of T1-weighted images for improved detection of
anatomic detail and correlation of the alteration in local and
regional anatomy on the T1-weighted images with areas of
increased signal intensity on the T2-weighted images
4. Evaluation of specialized MRI pulse sequences that may be
specific to the region or disease process that is being evaluated
5. Correlation of the above imaging information with the patient’s
history, physical examination, and laboratory

28. WHAT THINGS TO EVALUATE
• Alignment
• Bone
• Ligaments
• Intervertebral Discs
• CSF
• Spinal Cord
• Roots and Foramina
• Extraspinal tissue

29. 1. Alignment

33. 2. Bone
• Vertebral body fracture
• Posterior element fracture
• Destruction due to infection or tumor
• Edema
• Degenerative change

36. 3. Ligaments
• Normal ligaments should have low signal
intensity on all pulse sequences

38. 4. Intervertebral disc
• The outer annulus  hypointense on T2-
weighted images
• The inner annulus (fibrocartilage and a high
proportion of type II collagen) and nucleus
pulposus (proteoglycan matrix and type II
collagen)  hyperintense on T2-weighted
images and hypointense on T1-weighted
images

41. • Disc herniations also classified by the location as
the following:
– Central (compression of the medial portion of the
spinal cord)
– Posterolateral (compression of the lateral portion of
spinal cord and nerve root)
– Lateral (compression of the nerve root only)

43. 5. CSF
• CSF  low signal intensity on T1-weighted
images and high signal intensity on T2-
weighted images
• T2-weighted images provide a myelographic
appearance that allows for the detection of
spinal stenosis

45. 6. Spinal Cord
• Sagittal T2-weighted images provide a
myelographic effect that allows for the
evaluation of spinal cord morphology and the
presence of extrinsic compression

46. Spinal Stenosis
• The term spinal stenosis describes the
compression of the neural elements in the spinal
canal, lateral recesses, or neural foramina

47. • Foraminal stenosis may be caused by a disc
herniation or uncovertebral or facet joint
hypertrophy.
• Central canal stenosis is most often caused by:
– Disc bulge or herniation
– Uncovertebral joint osteophyte formation
– Ligamentum fl avum hypertrophy
– Facet arthrosis
– Thickening, calcifi cation, or
– ossification of the posterior longitudinal ligament
or other structures

48. 7. Roots and Foramina
• The nerve roots have intermediate signal
intensity and are surrounded by high signal
intensity fat on T1-weighted images and by
high signal intensity CSF on T2- weighted
images.

50. Other Pathologic Conditions
• Tumors
Spine tumors are categorized by their
anatomic location
• Extradural
• Intradural–extramedullary
• Intramedullary

52. CERVICAL SPINE
• Sagittal Images
The T1-weighted and T2-weighted sagittal
images should be reviewed first to evaluate
the spinal anatomy

54. CERVICAL SPINE
• Axial Images
Cervical spine anatomy and anatomic
pathology are well visualized on axial T1-
weighted images;
T2-weighted images have good CSF-to-cord
contrast which allows evaluation of spinal cord
or nerve root compression

56. THORACIC SPINE
• The anatomic structures in the thoracic spine
are unique in that the ribs form two additional
articulations with the vertebrae:
– the costocentral joint (between the vertebral body
and the rib head) and
– the costotransverse joint (between the transverse
process and proximal rib).

57. LUMBAR SPINE
• Sagittal Images
The T1-weighted images are best used for
shows the full profile of the sacrum and most
of the lumbar vertebral bodies, spinal cord,
and cauda equina
The bright signal from CSF on T2-weighted
images provides a myelographic eff ect

58. LUMBAR SPINE
• Axial Images
the degree of contribution of the three
primary contributors to spinal stenosis (disc
pathology, facet arthropathy, and ligamentum
flavum hypertrophy) should be noted

60. case
• A 38-year-old male presents with a three month
history of low back pain and right leg pain that
has failed to improve with nonoperative
modalities including selective nerve root
corticosteroid injections. Leg pain and
paresthesias are localized to his buttock, lateral
and posterior calf, and the dorsal aspect of his
foot. On strength testing, he is graded a 4/5 for
plantar-flexion and 4+/5 to ankle dorsiflexion. On
flexion and extension radiographs there is no
evidence of spondylolisthesis

62. • Figures A and B show the axial and sagittal
sequences of a T2-weighted MRI of the lower
lumbar spine. A large L5/S1 para-central disc
herniation is seen that has migrated cephalad

63. THANK YOU