This document discusses an MRI of the lower spine. It begins with an overview of spine anatomy, including the different regions of the spine. It then discusses common spine injuries and diseases that MRI is used to evaluate. The document outlines the main indications for lumbar spine MRI and principles of how the scans work, including different weightings used to highlight fat, water, and other tissues. It describes techniques like fat suppression and imaging planes used to best view structures of interest.

1. LOWER SPINE MRI
‫שי‬ ‫גל‬
‫רפואית‬ ‫הנדסה‬
MRI‫ברפואה‬ ‫לדימות‬

2. THINGS WE’LL TALK ABOUT
 Spine Anatomy
 Spine Injuries/Diseases
 MRI Indications
 Lumbar Spine MRI Principles
 No More Time…

3. SPINE ANATOMY
 8 Cervical
 12 Thoracic
 5 Lumbar
 Sacrum + Coccyx

4. SPINE ANATOMY
The aorta and vena cava
Separating around the level of
the L3/L4 disc space
Aorta
Vena cava
Iliac arteries
Iliac veins
Midsacral vessels

5. SPINE ANATOMY
 Lumbar Spine Anatomy

6. SPINE INJURIES/DISEASES

7. MRI INDICATIONS

8. MRI INDICATIONS
MRI‫פחות‬
‫בדימות‬ ‫יעיל‬
‫פגיעות‬ ‫של‬
‫אנטומיות‬

9. RI PRINCIPLESMPINESUMBARL
 T1- when contrast is dependent on differences
in longitudinal magnetic relaxation times
values between various tissues the image is
called “T1-weighted”.
 T2- when contrast is mostly determined by
differences in transverse magnetic relaxation
values the image is called “T2-weighted”.

10. RI PRINCIPLESMPINESUMBARL
 T1: T1-weighting is mainly used to produce a
“fat image”.

11. RI PRINCIPLESMPINESUMBARL
 T2- bright signal intensity of water (CSF,
nucleus pulposus) is mainly seen in images
with T2-weighting, therefor known as “water
images”.

12. RI PRINCIPLESMPINESUMBARL
 FastSpinEcho vs. ConventionalSpinEcho in T2-
• in a CSE sequence epidural fat & bone marrow fat have low
signal intensity, while FSE produces a much higher fat
signal.
• In FSE T2-weighted images epidural and foraminal fat may
be almost in the same intense as CSF.
• FSE T2-W images provide “water contrast” as well as “fat
contrast”.

13. RI PRINCIPLESMPINESUMBARL
Cont.
• Difficult to see degenerative changes/
metastases/ osteomyelitis (bone infection)
symptoms.
• Alternative option for “water image” is to use a
T2* -weighted gradient-echo (GRE) sequence
(but mostly for cervical area).

14. RI PRINCIPLESMPINESUMBARL
 How to reduce fat from our picture-
• Short TI inversion recovery (STIR).
• Spectral fat suppression by pre-saturation (SPIR).

15. RI PRINCIPLESMPINESUMBARL
 Imaging Planes-
generally, in sectional imaging, anatomic surfaces/
structures are best imaged in a plane which lies
perpendicular to the surface of interest.
• Sagittal: Images in this plane are best for demonstrating
disc herniations, mid-sagittal diameter of the spinal canal,
increase or decrease in sagittal diameter of the spinal
canal.
axial

16. RI PRINCIPLESMPINESUMBARL
• Axial: extent of a disc abnormality, lateral recesses of the spinal
canal are best studied in the axial plane, The foramen and its
contents can be studied in axial images (less well than in the
sagittal plane).
• Coronal: This imaging plane is used only rarely in diagnosis of
degenerative disease. Some spinal deformities such as
scoliosis or hemivertebra are imaged best in the coronal plane.

17. RI PRINCIPLESMPINESUMBARL
Fat areas
Fat, vascular,
infected areas
Liquid areas
Summary

18. Bye Bye