LOWER SPINE MRI
גל שי הנדסה רפואית
MRI לדימות ברפואה
THINGS WE’LL TALK ABOUT
Spine Anatomy
Spine Injuries/Diseases
MRI Indications
Lumbar Spine MRI Principles
No More Time…
SPINE ANATOMY
8 Cervical
12 Thoracic
5 Lumbar
Sacrum + Coccyx
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
SPINE ANATOMY
Lumbar Spine Anatomy
SPINE INJURIES/DISEASES
MRI INDICATIONS
MRI INDICATIONS
MRI פחות
יעיל בדימות
של פגיעות
אנטומיות
RI PRINCIPLES MPINE SUMBAR L
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”.
RI PRINCIPLES MPINE SUMBAR L
T1: T1-weighting is mainly used to produce a
“fat image”.
RI PRINCIPLES MPINE SUMBAR L
T2- bright signal intensity of water (CSF,
nucleus pulposus) is mainly seen in images
with T2-weighting, therefor known as “water
images”.
RI PRINCIPLES MPINE SUMBAR L
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”.
RI PRINCIPLES MPINE SUMBAR L
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).
RI PRINCIPLES MPINE SUMBAR L
How to reduce fat from our picture-
• Short TI inversion recovery (STIR).
• Spectral fat suppression by pre-saturation (SPIR).
RI PRINCIPLES MPINE SUMBAR L
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
RI PRINCIPLES MPINE SUMBAR L
• 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.
RI PRINCIPLES MPINE SUMBAR L
Fat areas
Fat, vascular,
infected areas
Liquid areas
Summary
Bye Bye
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