Tomografia komputerowa B. Augustyniak. Tomografia komputerowa – CT 3D.

Tomografia komputerowa

B. Augustyniak

Tomografia komputerowa – CT 3D

CT - 3D

CT - aparatura

Siemens Somatom Plus 4 Power / Expert

http://www.siemensmedicalparts.com/xraytubes.htm#ct

Siemens Somatom AR.xx

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

http://www-leti.cea.fr/commun/AR-2002/04-medical%20imaging/04-1-chabbal.pdf

- X-Ray converter : scintillator or photoconductor

- Active aSi:H readout matrix

- External readout Amplifiers/multiplexers and lines drivers

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

http://www-leti.cea.fr/commun/AR-2002/04-medical%20imaging/04-1-chabbal.pdf

- Vapour grown

- Tl doped for green emission

- Columnar structure

- Large area 43cm x 43 cm

- Thickness ~ 500 - 600µm

- X-ray Absorption : 80 % at

60keV

CT – zasada rejestracji i rekonstrukcji

CT - tworzenie obrazu 3D

Obrazy CT 2D - głowa

•ACUTE EPIDURAL HEMATOMA•Subdural Hematoma, Acute on Chronic

http://www.mdchoice.com/xray/ctscan/Ct.asp

Obrazy CT 2D - głowa (2)

•AREA OF DEEP WHITE MATTER EDEMA WITHIN RIGHT PARIETO-

FRONTAL REGION

•OCCIPITAL BONE FRACTURE

http://www.mdchoice.com/xray/ctscan/Ct.asp

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)

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

http://www.mdchoice.com/xray/ctscan/Ct.asp

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

http://www.microphotonics.com/skymto.html#applications

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

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

http://www.toshiba-itc.com/cat/en/ref/prod02_samp.html

Przekrój opornika (D – 10 mm)

mikro CT – obrazy kolorowe

Tracking ExamplesTracking Examples

S. Park; http://www.ices.utexas.edu/~smpark/PED/PED2nd.ppt

CD 3D - przykładYXLON International X-Ray GmbH,

D.Shlösser, R. Rowecki

CT – zalety i wady

• Wyznacza b. dokładnie strukturę PRZESTRZENNĄ a przy stosunkowo małym natężeniu jest to ‘metoda bezpieczna’ w badaniu obiektów biologicznych

Zalety

Wady

• Długotrwała ekspozycja (?) – możliwe obrazy obiektów NIERUCHOMYCH