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2 Introduction
• Requirements of modern neurosurgery
– Maximum removal while preserving neurological function
– Precise spatial visualization, localization
– Information beyond structure: blood supply, function
Multimodal imaging in neurosurgical planning – Neuronavigation and „augmented reality”
reality
Trepanatio
Modern neurosurgery
Modern? Neurosurgery
5 The main indications of
neurosurgery and planning
• Most common indications
• Tumors
– Meningeoma
– Metastasis
– Glioma (low-grade, high-grade), PCBL
– Pediatric tumors (medulloblastoma, PNET)
• AVM
• Cortical dysplasia, degeneratio
• Epilepsy surgery
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Multimodal imaging for neurosurgery
7 What clinicians should ask
Anatomy
• Location of craniotomy? Conventional MRI
Tumor localization (Gd!)
• Tumor localization, cortical eloquent areas
Vessels
• Vessels structure
DTI,
• Eloquent areas Eloquent t t
El t tracts tractography
– White matter fibers
Function, laterality fMRI
– Functional domains
• Function laterality (speech, movement) Tumor metabolism
PET, MR
spectroscopy
• Tumor characterization Stereotactic
CT
• Post operative imaging + controll planning
Localization Neuronavigation systems
Introduction
9 Basics of multimodal imaging 10 MRI sequences
Multimodal • Conventional MRI sequences to display anatomy:
• T1-weighted / post-Gd (vessels) or TOF time of flight
– Parallel / fused display of different imaging
• T2-weighted / flair
modalities • Segmentation of cortical structure, vasculature
– Their benefits multiply • Segmentation of lesion / tumor
– New information • Segmentation of markers
– Image processing
• Spatial alignment
• Standard space
• Normalization
Information from Information from
11 conventional MR images 12 conventional MR images
• Skin, muscles, skin markers for neurosurgery • Vessels: (1) Contrast MRI (2) TOF
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Information from Diffusion information:
13 conventional MR images 14 DTI and fibertracking
• Cortex
• tumor
• Displaying white matter tracts
• Tumor adjacent tracts
• Diffusion mapping
• Characterizing pathologies
Diffusion information: Diffusion information:
15 DTI and fibertracking 16 DTI and fibertracking
• Térbeli illesztés, regisztráció • Fibertracking: the method to display brain
• Tenzorterek regisztrációja a strukturális felvételekhez (CT,MRI)
tracts in vivo by MRI
• Representation: line / tubes / probabilities
–
• Eredmény: kevesebb torzítás, pontosabb térbeli leképzés, koordináta
rendszer.
Diffusion information: Diffusion information:
17 DTI and fibertracking 18 DTI and fibertracking
• Segmenting and localizing main structures of the WM (pl. tr. cortico-
spinalis, FLS, cc)
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Diffusion information:
19 DTI and fibertracking
• DTI acquisitions are distorted
• DTI has to be aligned with the T1-weighted brain image
• .
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Bevezetés
40 A multimodális képalkotás alapjai
Bevezetés Bevezetés
41 A multimodális képalkotás alapjai 42 A multimodális képalkotás alapjai
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Bevezetés Bevezetés
43 A multimodális képalkotás alapjai 44 A multimodális képalkotás alapjai
Bevezetés Bevezetés
45 A multimodális képalkotás alapjai 46 A multimodális képalkotás alapjai
Bevezetés Bevezetés
47 A multimodális képalkotás alapjai 48 A multimodális képalkotás alapjai
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Bevezetés Bevezetés
49 A multimodális képalkotás alapjai 50 A multimodális képalkotás alapjai
Second step: the actual fMRI acquisition
51 Functional MRI
T2*-weighted images
• Image contrast relates to neuronal activity
• Low spatial resolution (3x3x5 mm)
• One volume of the brain is acquired in 2 seconds!
• We acquire many volumes in time (4D), ie. 150
• Repeated scanning
…
first volume
(2 sec to acquire)
Paradigm and block design
Functional images
fMRI ROI
54 fMRI
~2 sec signal Time
(% change Course
• fMRI also distorts, image alignment necessary
– To patients anatomical (T1) images
Time Tasks – To standard neuroimaging spaces / atlases:
– Talairach atlas /MNI atlas
Statistical
activation map
on T1 image
Time
Region of interest ~ 5 minutes
kijelölés (ROI)
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Lesion in left precentral gyrus. Question:
CST?
Right hand activation (finger-tapping test)
Forrás: Katona P., DEOEC Forrás: Katona P., Jakab A. DEOEC
Summary – multimodality in
neurosurgery
• Locate anatomy
• Locate vessels
• Locate eloquent (neighbouring) areas
•LLocate white matter t t
t hit tt tracts Case 1
1.
• Locate functional domains
• Plan treatment
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Focal cortical dysplasias Dysplasia - Dysgenesis
•Cortical dysplasia is a congenital abnormality where the
neurons in an area of the brain failed to migrate in the • Greenfield’s Neuropathology – Dysplasia
proper formation in utero. of cerebral cortex
•Occasionally neuronswill develop that are larger than – Agyria
normal in certain areas.
•This causes the signals sent through the neurons in these – Pachygiria
areas to misfire, which sends an incorrect signal. It is – Polymicrogyria
commonly found near the cerebral cortex and is associated
with seizures.
– Heterotopia
•Cortical dysplasia is estimated to be present in 1 in 2,500 – Focal cortical dysplasia (FCD)
newborns, making it one of the most common cortical
malformations.
• Neuronal migration disorder
Palmini A, Najm I, Avanzini G, et al. Terminology and classification of the
J Neurol Neurosurg Psychiatry. 1971 August; 34(4): 369–387. cortical dysplasias. Neurology 2004;62(6 suppl 3):S2–S8.
Abnormal proliferation
FCD Type I
Focal cortical dysplasia
• Abnormal cells anywhere from the ventricular
wall to the cortex
• Broadened gyrus, slightly irregular sulcus
• Non enhancing
• Adjacent cortex slightly thickened
• Temporal localisation is common
• Marked by slightly broadened sulcus
• Hasznos a kontrollok során a fokozott figyelem,
mert a korral egyértelmübbé válhat
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67 Case 1. 68 Case 1.
Infant, generalized epileptic seizures. CT negative. Background: focal
cortical dysplasia
Case 2
2.
Case 2.
Pontine gliomas
•Brain stem tumors account for 10 percent of pediatric brain
tumors. The peak incidence is between ages 5 and 10.
Pontine Gliomas - The patients' symptoms often improve
dramatically during or after six weeks of irradiation.
Unfortunately, problems usually recur after six to nine
months, and progress rapidly. Survival past 12 to 14 months
is uncommon, and new approaches to treating these
tumors are urgently needed.
Midbrain/Medullary Gliomas - With the use of radiation
therapy, these patients often to well. Long-term survival
ranges from 65 to 90 percent for brain stem tumors that
arise from the midbrain or medulla. 3 yr, F, ICP signs, cerebellum – tonsillar herniation
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Jobb oldali nézet
Jobb oldali nézet
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Elülső nézet felülnézet
jobb Bal
jobb Bal
sin
jug ICA
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Hátsó nézet a IV.
agykamra felől
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Glioblastoma multiforme
•Glioblastoma multiforme (GBM) is the most common and
most aggressive malignant primary brain tumor in humans,
involving glial cells and accounting for 52% of all functional
tissue brain tumor cases and 20% of all intracranial tumors.
Despite being the most prevalent form of primary brain
Case 3. tumor, GBM incidence is only 2–3 cases per 100,000
, y p ,
people in Europe and North America. According to
the WHO classification of the tumors of the central nervous
system, the standard name for this brain tumor is
"glioblastoma"; it presents two variants: giant cell
glioblastoma and gliosarcoma.
•Treatment can involve chemotherapy, radiation,
radiosurgery, corticosteroids, antiangiogenic therapy,
surgery[1] and experimental approaches such as gene
transfer.[2]
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ICE
T
ICE
T ICE
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T
T
T T
Case 4
4.
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Low grade gliomas
Gliomas are named according to the specific type of cell they share histological
features with, but not necessarily originate from. The main types of gliomas are:
Ependymomas — ependymal cells.
Astrocytomas — astrocytes (glioblastoma multiforme is the most common
astrocytoma).
Oligodendrogliomas — oligodendrocytes.
Case 5
5. Mixed gliomas, such as oligoastrocytomas, contain cells from different types of
glia.
g , g y , yp
Gliomas are further categorized according to their grade, which is determined
by pathologic evaluation of the tumor.
Low-grade gliomas [WHO grade II] are well-differentiated (not anaplastic);
these are not benign but still portend a better prognosis for the patient.
High-grade [WHO grade III-IV] gliomas are undifferentiated or anaplastic; these
are malignant and carry a worse prognosis.
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VISUALIZATION OF STRUCTURE
Recidive tumor, 2 foci, purple and magenta
Markers on the skin
removed temporal lobe parts
Case 6
6.
OPTIC RADIATION
CORTICOSPINAL TRACT
VISUALIZATION OF FIBERS
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AVMs Diagnosis by angiography
•Arteriovenous malformation or AVM is an abnormal connection
between veins and arteries, usually congenital. This pathology is widely known because of its
occurrence in the central nervous system, but can appear in any location. An arteriovenous
malformation is a vascular anomaly. It is a RASopathy. The Spetzler-Martin grading system
developed at the Barrow Neurological Institute is utilized by neurosurgeons to determine
operative versus nonoperative management when approaching these lesions.
Diagnosis by angiography Diagnosis by MRI (T1 and T2-w)
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Case 7. – large GBM
Treatment: d b lki
T debulking
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C11 methionine – MRI – DTI
fusions
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PET imaging PET imaging
• fdsfsd • FDG: F-18 fluorodeoxyglucose positron
emission tomography (FDG-PET)
– Glucose metabolism, perfusion
– Necrosis: no FDG
• C11 – methionine
– Membrane turnover
– Cellular metabolism, tumor activity
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FDG – MRI – DTI fusions
215 Stereotaxic neurosurgery 216 Planning for Gamma Knife
• Modalities:
– CT: 1x1x1 mm voxel size with FRAME
– MRI:
• 3DT1 (anatomy, vessels)
• T2 (pathology, oedema, tumor etc.)
• FIESTA: acoustic neurinomas
– DTI
– Multimodal image fusions for planning
DE OEC Gamma Radiosurgery Centre
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Műtéti tervezés CT – 3DT1 MR regisztráció (gammakés)
Jelszó: multimodalitás!
Sztereotaxia / sugársebészet (gammakés)
Anatómiai kép: 3DT1, de CT, mint koordináta rendszer
és geometriai referencia
g
3DT1 MR – CT
MRI – DTI
- Automatic (maximalisation relative entropy)
CT – DTI / PET / fMRI - Manual correction (with internal „landmarks”)
To this time, manual correction was necessary in 60% of
the cases
- Optimalised automatic registration
CT és T2-súlyozott MR fúziója CT - TOF
1,2x1,2x1,2 mm
0,7x0,7x0,7 mm 190 slices
40-60 slices 6 mins
4 mins Contrast agent
Képregisztrációk (gammakés) Képregisztrációk
(3DT1 + DTI)
T1-CT Fiesta-CT TOF-CT
2008: approx. 50 patients
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Képregisztrációk (CT + DTI)
Case 8
8.
CT + ADC map CT + colorized FA map
Acoustic neurinomas Acoustic neurinomas
•A vestibular schwannoma, often called an acoustic neuroma,[1] is
a benign primary intracranial tumor of the myelin-forming cells of the vestibulocochlear
nerve(CN VIII).[2] The term "vestibular schwannoma" involves the vestibular portion of
the 8th cranial nerve[3] and arises from Schwann cells, which are responsible for
themyelin sheath in the peripheral nervous system. Approximately 3,000 cases are
diagnosed each year in the United States with a prevalence of about 1 in 100,000
worldwide. It comprises 5-10% of all intracranial neoplasms in adults. Incidence peaks in
the fifth and sixth decades and both sexes are affected equally.
28 éves nő 28 éves nő
Acousticus neurinoma Acousticus neurinoma
Gamma Sugársebészeti Központ Gamma Sugársebészeti Központ
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Thank you for your attention!
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