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