Transcript Tomografia komputerowa to jest TO

Tomografia komputerowa
B. Augustyniak
Tomografia komputerowa – CT 3D
CT - 3D
CT - aparatura
Siemens Somatom Plus 4 Power /
Expert
Siemens Somatom AR.xx
http://www.siemensmedicalparts.com/xraytubes.htm#ct
Detektory X (1)
• The replacement of the medical radiographic film has been
the main driver, during the last decade for large area X-ray
detectors development
• Several Flat Panel X-Ray detectors (FXD) are now available,
all of them using Amorphous Silicon Technology, for digital
radiography system
• FXD for dynamic imaging ( 30 fps) of the heart have been
recently introduced
http://www-leti.cea.fr/commun/AR-2002/04-medical%20imaging/04-1-chabbal.pdf
Detektory X (2) – wymagania
http://www-leti.cea.fr/commun/AR-2002/04-medical%20imaging/04-1-chabbal.pdf
Detektory X (3) budowa
- X-Ray converter : scintillator or photoconductor
- Active aSi:H readout matrix
- External readout Amplifiers/multiplexers and lines drivers
http://www-leti.cea.fr/commun/AR-2002/04-medical%20imaging/04-1-chabbal.pdf
Detektory X (4) budowa
Two designs are currently used
http://www-leti.cea.fr/commun/AR-2002/04-medical%20imaging/04-1-chabbal.pdf
Detektory X (5) budowa
Thallium doped Cesium Iodine (CsI) screen
- Vapour grown
- Tl doped for green
emission
- Columnar structure
- Large area 43cm x 43 cm
- Thickness ~ 500 - 600µm
- X-ray Absorption : 80 % at
60keV
http://www-leti.cea.fr/commun/AR-2002/04-medical%20imaging/04-1-chabbal.pdf
CT – zasada rejestracji i rekonstrukcji
CT - tworzenie obrazu 3D
Obrazy CT 2D - głowa
•Subdural Hematoma, Acute on
Chronic
http://www.mdchoice.com/xray/ctscan/Ct.asp
•ACUTE EPIDURAL HEMATOMA
Obrazy CT 2D - głowa (2)
•OCCIPITAL BONE FRACTURE
http://www.mdchoice.com/xray/ctscan/Ct.asp
•AREA OF DEEP WHITE MATTER
EDEMA WITHIN RIGHT PARIETOFRONTAL REGION
Obrazy CT 2D - środek
TYPE A AORTIC DISSECTION
The areas marked T demonstrate
flow within the true lumen of a
aortic dissection which involves
both the ascending as well as
descending portions of the arch
on this examination. The areas
marked F correspond to the false
lumen
http://www.mdchoice.com/xray/ctscan/Ct.asp
Obrazy CT 2D środek (2)
http://www.mdchoice.com/xray/
ctscan/Ct.asp
The axial CT scan examination of the lower chest done without the use of
intravenous contrast shows a loculated left pleural effusion with air
demonstrated within its confines which indicate an infected pleural space or the
presence of a bronchopleural fistula. The arrow points to an area where there is
communication between the pleural effusion and the extrapleural space, notably
in this case the musculature of the lateral chest wall. This is radiologically
compatible with a fistula communication between the possibly infected pleural
fluid and the extrapleural space and represents an empyema neccesitans
Najnowsze osiągnięcia CT
1) mikro – CT
2) kolorowanie obrazu CT
http://www.toshiba-itc.com/cat/en/prod02.html
http://www.toshiba-itc.com/cat/en/prod02.html
Mikro-CT
The Micro CT technique can be for a wide variety of samples
producing detailed structural images of objects as diverse as
bone, composite fibers, electronic components, seeds,
diamonds and wood.
The instrumentation comprises a finely focused sealed X-ray
tube, a precision sample manipulator, an X-ray CCD camera
and a Dual Pentium workstation with tomography software
running under WindowsXP.
There are four versions of the 1172 Micro CT instrumentation
depending on your choice of energy level (80Kv or 100 Kv
and camera resolution (10 Mega-pixel or 1.3 Mega-pixel)
http://www.microphotonics.com/skymto.html#applications
Mikro-CT
-aparatura
http://www.microphotonics.com/skymto.html
Mikro-CT
-aparatura
http://www.microphotonics.com/skymto.html
Mikro-CT
• Two 130 kV ultra-high resolution microfocus x-ray systems
(with integrated high voltage power supply and controller)
• Focal spot size as low as 7 microns
• Two 100/50 mm dual-field image intensifiers
• Two 1600 x 1200 x 30 frames/sec CCD cameras
• Dual Xeon® workstation with high capacity disk array
• Precision rotating gantry and a precision specimen positioner
• Computer-configurable source-to-image distance geometries
• High-speed data and power slip ring for continuous rotation
http://www.bio-imaging.com/medproduct.asp?p=36
Smallest detail
detectability
10 Mpixel Camera ~ 1um
1.3 Mpixel Camera ~2um
X-ray source
sealed microfocus X-ray tube, air cooled,
>10000h lifetime
spot size
<8um@8W , 20-80kV, 0-100uA spot size
X ray detector
10 Megapixel
(4000x2300) 12-bit digital cooled CCD with
fibre optic coupling to scintillator (50mm field of
view)
Maximum object
size for
reconstruction
35mm in diameter for standard scan, 68mm in
diameter for scan with camera offset (twice
longer)
Reconstruction time 6.8 sec per cross section 1024x1024 pixels
(float point cone-beam reconstruction, 0.9
deg./step)
Radiation safety
<1uSv/h at any point of the instrument surface
http://www.microphotonics.com/skymto.html#applications
Mikro-CT -przykłady
Kolano myszy
http://www.skyscan.be/next/home.htm
Wnętrze kości
http://www.microphotonics.com/skymto.html#applications
Mikro-CT –przykład cd
Shadow X-ray Image
Cross section of a capacitor
3D Reconstruction of capacitor
http://www.microphotonics.com/skymto.html#applications
Mikro – CT przykłady
Przekrój ołówka
Przekrój opornika (D – 10 mm)
http://www.toshiba-itc.com/cat/en/ref/prod02_samp.html
mikro CT – obrazy kolorowe
S. Park; http://www.ices.utexas.edu/~smpark/PED/PED2nd.ppt
CD 3D - przykład
YXLON International X-Ray GmbH,
D.Shlösser, R. Rowecki
CT – zalety i wady
Zalety
• Wyznacza b. dokładnie strukturę PRZESTRZENNĄ a
przy stosunkowo małym natężeniu jest to ‘metoda
bezpieczna’ w badaniu obiektów biologicznych
Wady
• Długotrwała ekspozycja (?) – możliwe obrazy
obiektów NIERUCHOMYCH