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FANNP 24TH NATIONAL NNP SYMPOSIUM: CLINICAL UPDATE AND REVIEW
A11b
From Polaroid to Digital Photography:
How to Interpret Neuroimaging
Michael D. Weiss, MD
Associate Professor
Department of Pediatrics, Division of Neonatology
University of Florida, Gainesville, FL
The speaker has signed a disclosure form and indicated he has no significant financial interest or relationship with the companies or the
manufacturer(s) of any commercial product and/or service that will be discussed as part of this presentation.
Session Summary
This session will provide an overview of neuroimaging. Bedside cranial ultrasound will be covered in both
the term and preterm neonate. MRI will be reviewed pertaining to HIE and term corrected. The optimal
timing of imaging will be discussed, as well as the outcome data which can be obtained.
Session Objectives
Upon completion of this presentation, the participant will be able to:
 understand an overview of IVHs;
 identify the two major staging systems for IVHs;
 compare the advantages and disadvantages of CT scans;
 understand the basics of MRI;
 explain cases as examples of abnormal MRIs.
References
Gano, D., Chau, V., Poskitt, K.J., Hill A, et al. (2013). Evolution of pattern of injury and quantitative MRI on days 1 and 3 in
term newborns with hypoxic-ischemic encephalopathy. Pediatric Research, 74(1): 82-87.
Miglioretti, D.L., Johnson, E., Williams, A., Greenlee, R.T, et al. The use of computed tomography in pediatrics and the
associated radiation exposure and estimated cancer risk. JAMA Pediatrics, 167(8): 700-7.
Rutherford, M.A. (2002). MRI of the Neonatal Brain (4th ed.). W.B. Saunders.
van Laerhoven, H., de Haan, T.R., Offringa, M., Post, B. & van der Lee, J.H. (2013). Prognostic tests in term neonates with
hypoxic-ischemic encephalopathy: A systematic review. Pediatrics, 131(1): 88-98.
Volpe, J.J. (2001). Neurology of the newborn. Philadelphia, PA: W.B. Saunders.
Volpe, J.J. (2009). Brain injury in premature infants: A complex amalgam of destructive and developmental disturbances.
Lancet Neurology, 8(1): 110-24.
Session Outline
See presentation handout on the following pages.
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FANNP 24TH NATIONAL NNP SYMPOSIUM: CLINICAL UPDATE AND REVIEW
Disclosure Statements
From Polaroid to Digital
Photography: How to interpret
neuroimaging
Michael D. Weiss, M.D.
University of Florida
Department of Pediatrics
Division of Neonatology
• I have no relevant financial relationships to
disclose or conflicts of interest to resolve.
• I will not discuss any unapproved or offoff
label, experimental or investigational use of
a product, drug or device.
I am Not a Neuroradiologist
Head US- Polaroids
IVH
Neuropathology- Anatomy
• Germinal Matrix
Neuropathology
A11b: HOW TO INTERPRET NEUROIMAGING
– Ventrolateral to lateral ventricle
– Site of neuronal precursors
between 10-20
10 20 weeks of gestation
– Third trimester becomes site of
glial precursors
– Many thin-walled vessels
– 2.5 mm at 24 weeks
– 1.4 mm at 32 weeks
– Involuted by 36 weeks
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FANNP 24TH NATIONAL NNP SYMPOSIUM: CLINICAL UPDATE AND REVIEW
Neuropathology- Anatomy
Pathogenesis
Pathogenesis
Pathogenesis
• Intravascular Factors
–
–
–
–
–
Fluctuating cerebral blood flow
Increases in cerebral blood flow
Increases in cerebral venous pressures
Decreases in cerebral blood flow
Platelet and coagulation disturbances
• Vascular Factors
– Tenuous Capillary integrity
– Vulnerability of matrix capillaries to HI injury
• Extravascular Factors
– Deficient vascular support
– Fibrinolytic activity
– Postnatal decrease in tissue pressure
Pathogenesis
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FANNP 24TH NATIONAL NNP SYMPOSIUM: CLINICAL UPDATE AND REVIEW
Pathogenesis
Pathogenesis
Pathogenesis
Ventilated premature infant with respiratory distress syndrome
Decreases in
CBF
Fluctuating
CBF
Increases in
CBF
Increases in
cerebral venous
pressure
Ventilated premature infant with respiratory distress syndrome
Decreases in
CBF
Fluctuating
CBF
Endothelial injury
Neurology of the Newborn. Volpe, Page 537
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Increases in
CBF
Increases in
cerebral venous
pressure
Vulnerable germinal matrix
Neurology of the Newborn. Volpe, Page 537
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FANNP 24TH NATIONAL NNP SYMPOSIUM: CLINICAL UPDATE AND REVIEW
Pathogenesis
Pathogenesis
Ventilated premature infant with respiratory distress syndrome
Decreases in
CBF
Fluctuating
CBF
Endothelial injury
Increases in
cerebral venous
pressure
Increases in
CBF
Ventilated premature infant with respiratory distress syndrome
Decreases in
CBF
Fluctuating
CBF
Endothelial injury
Vulnerable germinal matrix
Increases in
cerebral venous
pressure
Increases in
CBF
Vulnerable germinal matrix
Capillary rupture
Capillary rupture
Intravascular
platelet-capillary
and/or coagulation
disturbances
Extravascular:
Fibrinolytic activity
IVH
Neurology of the Newborn. Volpe, Page 537
Neurology of the Newborn. Volpe, Page 537
Pathogenesis
Classification--Papille
–
–
–
–
Grade I:
Grade II:
Grade III:
Grade IV:
Germinal matrix
Intraventricular, no dilation
Intraventricular with dilation
Intraventricular,
Intraparenchymal
Neurology of the Newborn. Volpe, Page 537
Classification--Volpe
Why Difference in Classifications?
• Grade IV is not just a bad grade III
• Theory 1: Venous Infarction
–P
Pressure from
f
IVH iimpedes
d bl
bloodd flow
fl through
th
h
venous system, causing hypoperfusion of the
area, and infarction
• Theory 2: Blood in the ventricle releases
vasoactive compounds impedes blood flow,
leading to infarction
Neurology of the Newborn. Volpe, Page 541
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FANNP 24TH NATIONAL NNP SYMPOSIUM: CLINICAL UPDATE AND REVIEW
Axial
Coronal
Sagittal
Classification-Anatomy
Classification-Anatomy
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Classification-Anatomy
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FANNP 24TH NATIONAL NNP SYMPOSIUM: CLINICAL UPDATE AND REVIEW
Coronal
Classification-Grade I
Classification-Grade I
Classification-Grade II
Classification-Grade II
Sagittal
Sagittal
Classification-Grade III
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Classification-Grade III
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FANNP 24TH NATIONAL NNP SYMPOSIUM: CLINICAL UPDATE AND REVIEW
Classification-Grade III
Classification-IPE
CBF- Measurement
Classification-IPE
Classification-IPE
Resistive Index
Fetal and neonatal physiology. Polin, Fox, and Abman- Page 1747
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FANNP 24TH NATIONAL NNP SYMPOSIUM: CLINICAL UPDATE AND REVIEW
PHH
CT Scan- 35mm Photography
CT or not to CT
• Advantages– Very rapid test
– Very good at detecting blood
– Better visualization of brain structures than
HUS
• Disadvantage
– May triple the risk of brain tumors
MRI- High Resolution Digital
MRI
Images
MRI of the Neonatal Brain
Mar A.
Mary
A Rutherford
R therford
http://www.mrineonatalbrain.com/
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FANNP 24TH NATIONAL NNP SYMPOSIUM: CLINICAL UPDATE AND REVIEW
MRI- Basics
MRI- Basics
• Relies on protons of Hydrogen to produce
an image.
• http://www.youtube.com/watch?v=pGcZvS
http://www youtube com/watch?v=pGcZvS
G805Y
MRI- Basics
MRI- Basics
MRI- Basics
MRI- Basics
•
•
•
•
•
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T1 Basics
T2 Basics
DWI B
Basics
i
ADC Map
SWI Basics
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FANNP 24TH NATIONAL NNP SYMPOSIUM: CLINICAL UPDATE AND REVIEW
The Normal MRI
• We don’t image normal newborns
• Th
The following
f ll i slides
lid are a normall brain
b i
MRI
Normal Brain MRI
–
–
–
–
T1
T1
T2
Higher T1 signal in
perirolandic cortex and
corticospinal WM tracts
Darker signal in
myelinated WM
T1
39 week gestation
CDH
Apgar 1 minute: 8
Apgar 5 minutes: 9
T2
PLIC light on T1 and dark on T2
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High T1 signal in PLIC
T1
T2
Low T2 signal in PLIC
Heterogeneous WM signal
T2
High signal in globus palidus
and dorsal putamen and
ventrolateral thalami
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FANNP 24TH NATIONAL NNP SYMPOSIUM: CLINICAL UPDATE AND REVIEW
T1
T2
Diffusion-weighted images
B=0
B=1000
Myelinated corticospinal tract
What to look for on MRI for
babies with HIE
• Axial T1-weighted images
– Bright signal from increased intracellular Ca++
• Axial T2-weighted images
– Blurring of GW differentiation from increased
intracellular water in the cortex
– Bright signal in WM
• Diffusion-weighted images
– Restricted diffusion
• MR Spectroscopy
ADC map
Dark signal in
ventrolateral thalamus
results from low signal
on B=0
Notice gray-white
differentiation on
B=0
Case 1
•
•
•
•
•
•
36 weeks gestation
Fetal heart rate 60 at routine check-up
E
Emergent
t C-section
C
ti
Chest compressions, intubated
Apgar 1,3,4
Was cooled
– Lactate peak
Day 4
Injury to the basal
ganglia and
thalamus
T1
B=0
T2
B=1000
Day 47
High T1 signal
in basal
ganglia and
th l
thalamus
from
f
intracellular
calcium shift
and necrosis
ADC
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FANNP 24TH NATIONAL NNP SYMPOSIUM: CLINICAL UPDATE AND REVIEW
Case 2
•
•
•
•
Day 6
39 weeks gestation
C-section after failed vacuum suction
A
Apgars
00,3,5
35
Was cooled
Basal
Ganglia
normal
T1
T2
B=100
B
100
0
Diffusionweighted images
show injury in the
watershed cortex
and white matter
Day 5
Case 3
•
•
•
•
•
•
•
Case 3: Severe HIE
38 weeks
Ut i rupture
Uterine
t
Emergent C-section
Apgar 1, 3, 5
Seizures
Was cooled
B=0
B=1000
ADC
Day 5
Abnormal high
signal
throughout the
WM on T2
Blurring of GW
differentiation
more evident
on B=0 than
conventional
T2-weighted
images
T2
T1
Cortical pattern of
injury,
sensory cortex
parietal lobe
Blurry T2
White matter injury
Abnormal
Normal
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FANNP 24TH NATIONAL NNP SYMPOSIUM: CLINICAL UPDATE AND REVIEW
Abnormal T1
Normal T1
DWI – diffuse BG and WS pattern
Restricted diffusion in perirolandic cortex, basal
ganglia, thalami, cortical and WM watershed
zones
High T1 signal in putamen, insular cortex
Day 23
Case 4
•
•
•
•
•
•
High T1 signal from
calcium shift
Low WM signal from
necrosis
Day 2
35 weeks
Cocaine exposure in utero
S t
Spontaneous
vaginal
i l delivery
d li
Severe birth asphyxia
Apgar 0,0,0
Died on day 16
Day 15
Cortical volume loss
T2 Dark=blood
Normal
Comparison
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FANNP 24TH NATIONAL NNP SYMPOSIUM: CLINICAL UPDATE AND REVIEW
Day 3
Case 5
Increased signal T1
Restricted Diffusion
Motor Cortex
• 38 weeks
• C-section for fetal distress
Case 6
Day 49
•
•
•
•
•
40 weeks
C-section for fetal distress
A
Apgar
000
0,0,0
Seizures
Died on day 3
White matter and cortical loss with blood products and necrosis
Day 2
Day 2
Deep WM and
watershed injury
WM should
be ggray
y on T2
Lower in
Basal Ganglia
g
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FANNP 24TH NATIONAL NNP SYMPOSIUM: CLINICAL UPDATE AND REVIEW
Diffuse cortical
injury
Posterior limb
of internal
capsule
Case 7
• 38 weeks gestation
• Meconium aspiration
• Apgars
A
11,1,3
13
Day 3
MRS- basics
Optimizing MRI
• 3 critical sequences
– Axial T1
– Axial T2
– Diffusion-weighted
Diff i
i h d
Time of scan = 10
minutes
• B=0, B=1000, ADC
•
•
•
•
4mm slice thickness
1mm skip
FOV=160mm
3 averages if baby is holding still (otherwise 2)
– Sedation is not required
Timing of MRI
MRI- Preemies
• MRI findings evolve over time as injury
from excitotoxicity and oxidative stress
combine with injury from inflammation and
changes from repair.
• Image at 4 days and/or 7-10 days.
• Over the first few days, lactate peak on
MRS changes, peaking at about 5 days.
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