Lecture-4-a_NeuroImaging.pptx
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Transcript Lecture-4-a_NeuroImaging.pptx
Looking into the Nervous System
RM Clemmons, DVM, PhD, CVA, CVFT
Associate Professor of Neurology & Neurosurgery
University of Florida
Gainesville, FL 32608
http://Dog2Doc.com
Radiography
Myelography
CT
MRI
2.5 year old M
Great Dane
Always clumsy
Progressive
quadriparesis
over last few
months
Neurologic Exam
Slight root
signature in left
foreleg
Hyperactivity of all
four legs
Crossed Extensor
responses in the
rear legs
CP deficits in all 4
legs
Localization of Lesion
D
IVDD
A
Wobbler’s Disease
M
Cervical Spinal Cord
N
N
I
I
I
T
T
V
Spinal Cord Tumor
Myelitis
GME
• Problem List
1. Quadriparesis
Differential Dx
? 1. IVDD
2. Wobbler’s Disease
3. Inf/Inflam
4. Neoplasia
Diagnostic Approach
?
Treatment
?
MDB
CBC
Chemistry Profile
UA
Chest & Abdominal
Radiographs
Abdominal Ultrasound
Neurologic Tests
EMG
CSF Analysis
Cisternal
Titers
MRI
Client Education
SPECIMEN: CSF – AO
Color/Transparency:
Protein mg/dL
RBC/μL
WBC/μL
colorless/clear
16
16
4
A 30 cell differential count yielded the following:
1 Neutrophils
15 Lymphocytes
14 Mononuclear phagocytes
Two cytospin preparations are stained and microscopically examined. The
slides are of adequate staining and preservation of cellular detail with scant
hemodilution present against a colorless background that contains occasional
squamous epithelial contaminants. Approximately equal numbers of small,
weel-differentiated lymphocytes and variably reactive mononuclear
phagocytes are the predominant cell types.
No infectious agents or neoplastic cells are identified.
Interpretation: Normal CSF.
3DX - Negative for Dirofilaria immitis antigen, Borrelia
burgdorferi and Ehrlichia canis antibody.
RMS - Negative for Rickettsia rickettsii IgG AB by IFA: Titer
<64
BLM - Negative for Blastomyces by AGID.
DIS - CDV
IgG AB: 50
IgM AB: Negative
CRC - Negative for Cryptococcus antigen by latex agglutination
test
TO1 – Toxoplasma
IgG AB: Negative
IgM AB: Negative
NEO - Negative for Neospora caninurn IgG AB by IFA: Titer
<50
Needle EMG normal with a few
fibrillation potentials at C5-6
NCV 55 m/sec
F wave present
RNS- -nondecremental
SEP- -normal
O’Malley
Syringomyelia
Consider surgical option?
May continue to progress
Use antioxidants & occasional alternate-day
steroids
Reassess as needed
Machine settings
Time
Milliampers
KVp
Electrons from the cathode bombard the
spinning anode to produce X-rays
Tungsten anode
Photons spread in a fan effect with a “heel”
effect
6 year old FS Burnese
Mountain Dog
2 weeks history of
progressive exercise
intolerance &
weakness
Now cannot rise
S
Neurologic Exam
Progressive
weakness on
exercise
Reflexes intact
No CP deficits
Palpebral response
fatigues on
repeated stimulation
S
Localization of Lesion
D
A
M
Diffuse Neuromuscular
junctional disorder
N
N
I
I
Perineoplastic
Encephalomyelitis
Myasthenia
I
T
T
O
V
Chronic OP Toxicity
• Problem List
1. Generalized
weakness
2. Exercise Intolerance
3. Palpebral Fatigue
Differential Dx
? 1. Inf/Inflam
2. Neoplasia
3. Toxicity
Diagnostic Approach
?
Treatment
?
P
MDB
CBC
Chemistry Profile
UA
Chest & Abdominal
Radiographs
Abdominal Ultrasound
Bile Acids
Cholinesterase
Ammonia level
Neurologic Tests
EEG
CSF Analysis
Cisternal
Titers
MRI
P
Client Education
O
O
O
O
Myasthenia titer (anti-Ach-receptor antibody)
6.8
Normal < 0.06
O
Myasthenia Gravis (with Thymic Mass)
A
The prognosis is guarded to poor
May resolve in 3-6 months or continue for
life
Treat
Surgery
Steroids
Mestinon (anti-Achesterase)
Consider CAVM & TCVM approaches to
augment or instead of Western therapy
P
Iodinated contrast agent
Iohexol – single use 20ml bottles
Tentative doses
0.3 ml/kg if close to the lesion
0.45 ml/kg if distant from the lesion
Post myelography seizure possibility
Slices the patient in axial slices hence the CAT
Hounsfield or CT units
+1000 = densest bone
0 = water
-1000 = air
Windows may be chosen
One slice at a time vs. spiral
Hyperdense
Hypodense
Contrast
• Mineral
• Hemmorhage
• Fibrous/densely
cellular tissue
• Fluid
• Edema
• CSF
• Fat
• Chronic
hemorrhage
• Disruption of
BBB
• Falx
• Vascular
Bone and acute hemorrhage
3-D reconstruction and spatial resolution
+/-speed
$$$
Limitations of detail
Beam hardening
Iodinated contrast with potential for reaction
Anesthesia or sedation required
4 year old FS
Standard Poodle
4-5 day history of
posterior paresis
Jumped off 15
foot cliff 2 days
before signs
S
S
Localization of Lesion
D
IVDD
A
M
TL Spinal Cord
N
N
I
I
Spinal Tumor
Myelitis
GME
I
T
T
O
V
Fx/Dislocation
• Problem List
1. Posterior Paresis
2. Back Pain
Differential Dx
? 1. IVDD
2. Inf/Inflam
3. Trauma
4. Neoplasia
Diagnostic Approach
?
Treatment
?
P
MDB
CBC
Chemistry Profile
UA
Chest & Abdominal
Radiographs
Abdominal Ultrasound
Neurologic Tests
CSF Analysis
Cisternal
Titers
MRI/CT Scan
P
Client Education
O
O
O
O
O
SPECIMEN: CSF – AO
Color/Transparency:
Protein mg/dL
RBC/μL
WBC/μL
colorless/clear
26
46
4
A 30 cell differential count yielded the following:
1 Neutrophils
15 Lymphocytes
14 Mononuclear phagocytes
Two cytospin preparations are stained and microscopically examined. The
slides are of adequate staining and preservation of cellular detail with scant
hemodilution present against a colorless background that contains occasional
squamous epithelial contaminants. Approximately equal numbers of small,
well-differentiated lymphocytes and variably reactive mononuclear phagocytes
are the predominant cell types.
No infectious agents or neoplastic cells are identified.
O
Interpretation: Normal CSF.
3DX - Negative for Dirofilaria immitis antigen, Borrelia
burgdorferi and Ehrlichia canis antibody.
RMS - Negative for Rickettsia rickettsii IgG AB by IFA: Titer
<64
BLM - Negative for Blastomyces by AGID.
DIS - CDV
IgG AB: 50
IgM AB: Negative
CRC - Negative for Cryptococcus antigen by latex agglutination
test
TO1 – Toxoplasma
IgG AB: Negative
IgM AB: Negative
NEO - Negative for Neospora caninurn IgG AB by IFA: Titer
<50
O
Spinal Cord Concussion
A
The prognosis is good
Should continue to improve over 3 months
Treat
PEG
NSAIDS
Consider CAVM & TCVM approaches to augment
or instead of Western therapy
P
Normal Brain
Does not use x-rays
A strong magnetic field causes uniform
alignment of hydrogen protons
Relaxation of these protons emits radio
frequencies
Different tissues will emit signals of different
intensity during the relaxation phase
By changing the spin to echo times, TR
(repetition time) and TE (echo time) one may
visualize different structures
NMR phenomena
described in 1946
First human image
1977
Veterinary specific
units 2000
Magnet
Gradient Coils
RF Coil
Ancillaries
Table
Computer
Image processor
T1 weighted
Short TR
Short TE
T2 weighted
Long TR
Long TE
Proton density
Long TR
Short TE
T1
Less Mobile=Short relax
Mucinous fluids
Normal tissue
Abnormal Cells
Free Water
More mobile=Long relax
T2
Edema
Cellularity
Gliosis
Neoplasia
Inflammation
Congestion
De-myelination
GM>WM
Fat (gitter cells)
Hemmorhage (MetHb)
Protein binding (mucin,
cortical laminar
necrosis)
Melanin
Free Radicals
Paramagnetic agents
WM>GM
T2 Weighted
FLAIR
T1-W
T2-W
PD
• Good Anatomy
• Contrast Enhancement
• Juicy Pathology
• Vary contrast of anatomy
• “Free Sequence”
FLAIR
• Solid vs. Cystic
• Conspicuity
• Periventricular
GRE
• Paramagentic
• Blood, mineral
• MRA
STIR
• Differ fat from pathology
• Conspicuity
• FATSAT/SPIR for post contrast
Soft tissue neoplasia
Tissue inflammation
Vascular infarction
or anomalies
Neural degeneration
IVD protrusions
Defined as accumulation of CSF in the brain
associated with concurrent loss of white and/or
gray matter
Congenital
Outflow obstruction
De Novo
Brain disappears
DV
LAT
T2-horizontal
T1-coronal
T1-sagittal (lateral)
T1-sagittal (midline)
L
R
L
L
13 year old DSH
Brainstem Cyst
Severe
quadriparesis with
depression
4 weeks post-
operative
T1 with Contrast (gadolinium)
Skull Fracture with hemorrhage
& edema
Epidural
Intraventricular
Subdural
Intraparenchymal
Subarachnoid
Vasogenic
Cytotoxic
Interstitial
MRI showing swelling & edema of optic nerve (arrows)
Unilateral muscle
atrophy
Chronic in nature
Evident on CT or
MRI scans
Contrast MRI shows enlarged
CNV (arrows) with muscle atrophy
on affected side
T2 weighted
images assess
hydration of IVD
nucleus
T1 weighted
images look for
soft tissue
changes
SIGNALMENT: Canine: 4 year old, MC Dachschund
PRIMARY COMPLAINT: Posterior paralysis
HISTORY: The dog lives in an urban area. He was taken for
daily walks in the park. One week ago, he showed mild back
pain. Two days ago, the dog was found in the current
condition.
NEUROLOGIC EXAMINATION: The dog is BAR (bright, alert
and responsive). There were no cranial nerve deficits and the
forelegs were normal. There was no evidence of movement in
the rear legs. The dog is incontinent and there is no deep
pain. Reflexes in the rear legs were present and hyperactive.
The panniculus response is absent below L3 and there is
hyperpathia at L2.
4 year old,
Dachschund
Posterior Paralysis
Back Pain at L2
Rear leg paralysis
without deep pain
Neurofibrosarcoma
GRE nulling
Rounded/Mass
Like
Tumor (variable
Contrast)
GRE WNL
Abscess (ring
Enhance)
Wedge Shaped
(Mass Effect w/o
Mass)
Territorial Infarct
(poor Contrast
enhance)
Cyst (No enhance
Symmetric
Metabolic
Solitary
CNS
Lesion
Hematoma
Multifocal
Inflammation
Asymmetric
2nd Neoplasia
Vascular
Inflammation
Neoplasia
Metabolic
• Assymetric
• Multifocal>Focal
• Classic
Distributions
• Mass Effect
• Asymmetric
• Focal>Multifocal
• Classic
Distributions
signal changes
and
enhancement
• Mass Effect
• Symmetric
• Focal
• Classic
Distributions
• Cortex
• White matter
• Deep Grey
bodies
• No Mass Effect
Vascular
•
•
•
•
•
Asymmetric
Focal>Multifocal
Intra-axial
No Mass Effect
Classic
Distributions
• Lacunar vs.
territorial
fMRI (functional
MRI)
Baseline
Mannitol
Vascular evaluation
MRS (MR
spectroscopy)
DTI (diffusion
tensor imaging)
Mn Infusion
EA GB34