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Anatomický obraz
melanomablue
Positron Emission Tomography
MR Scan (or CT)
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n
4DPET_sm 4D-PET-CT_sm melanomablue os_neuro1 article_image
MR, CT
Anatomie
funkce
PET/CT
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Funkční obrazení
Glucose + Isotope (e+)
Injection(~2-5mCi)
Scan (15-30 minutes)
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Co je PET?
•Isotope production CYCLOTRONS
•Tracer production CHEMISTRY SYSTEMS
•Imaging SCANNER
RW3qtrRsmall
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Fyzikální princip
n
b+
b-
~1-3mm
511KeV
511KeV
• Pozitronová dráha 1-3 mm před
annihilací (závisí na energii)
• Zachování energie a momentu
- 511 keV fotony a
• Simultánní detekce dvou 511KeV fotonů �
- výsledek je přímka a současný přichod
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n
img005
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n
img008
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n
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Projection Data Collection
R
PMT
PMT
COINCIDENCE
PROCESSING
DETECTOR
RING
Processing
Electronics
Processing
Electronics
Coincidence
Processor
Data Sorting,
Histogram
Image Recon
Computer
Images
Basic Principles
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DetectorRing RW3qtrRsmall
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ex_ani
PET Image
My Objective è New and better detector design using GEANT4
è Better information to Physicians
è Better patient care and treatment
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lobe
Intra-pulmonary lesion
PET-CT fusion localizes
PET-CT
trauma-r
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nPrvní srdce má mykardální infarkt. Šipky ukazují poškozené oblasti (‘smrt tkáně).
nDruhé srdce je normální
Příklad : Myokardiální nekrózy
heart
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nPrvní obraz ukazuje maligní nádor, který nebyl diagnostikován běžnými zobrazovacími technikami.
(CT, MRI, mammogram)
nDruhý obraz již bohužel meta postižení.
Příklad: rakovina prsu
cancer
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Fyzikální princip
n
b+
b-
~1-3mm
511KeV
511KeV
• Simultánní detekce dvou 511KeV fotonů �
img004 RW3qtrRsmall DetectorRing
18F FDG ( 18F labeled fluorodeoxyglukoza )
PET/CT
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n
A6MED69 PET-CT2
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Žaludek karcinom
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Pankreas - karcinom
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Activity
A = DN/Dt [s-1]
A - activity
DN - mean number of radioactive decays
Dt - time interval
1 s-1 = 1 Bq (Becquerel)
1 Ci (Curie) = 3.7 x 1010 Bq
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Dose
D = De/Dm [J.kg-1]
D - dose
De - mean energy deposited by ionizing radiation to given material
Dm - mass of material
1 J.kg-1 = 1 Gy (Gray)
1 rad = 0.01 Gy
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Basic principles of radiosurgery
The first prototype of the Leksell Gamma Knife was installed in 1968 at Sophiahemmet in Stockholm,
Sweden.
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Diagram for the decay of 60Co nucleus
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Photon depth dose curves
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Basic principle of radiosurgery
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Dose profiles for the Leksell gamma knife
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Physical and technical principles
Radiation source: gamma rays from 60Co
No. of sources: 201
Collimators: 4, 8, 14, 18, mm
Stereotactic target localization: preferably MRI, CT not necessary, angiography
Leksell gamma knife
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Physical and technical principles
Leksell gamma knife
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Physical and technical principles
Leksell gamma knife
6-LGK_modelC
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Physical and technical principles
Leksell gamma knife
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Physical and technical principles
Leksell gamma knife
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Physical and technical principles
Leksell gamma knife
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P7020717 P7020718 P7020716 P7020719
Physical and technical principles
Leksell gamma knife
4 mm
8 mm
14 mm
18 mm
14 mm
14 mm
8 mm
8 mm
8 mm
8 mm
4 mm
4 mm
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Physical and technical principles
Leksell gamma knife
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Physical and technical principles
Linac radiosurgery or radiotherapy (BrainLAB system)
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Physical and technical principles
Linac radiosurgery or radiotherapy (BrainLAB system)
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Physical and technical principles
Linac radiosurgery or radiotherapy (BrainLAB system)
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Physical and technical principles
Linac radiosurgery or radiotherapy (BrainLAB system)
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Clinical applications-acoustic neuroma
3 years after LGK irradiation
during LGK irradiation
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Clinical applications-metastasis
6 years after LGK irradiation
during LGK irradiation
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