Transcript CT(computerized tomography)

Next Generation CAT System
Non-scanning CT (computerized tomography)
CT(computerized tomography) creates 3D views of what is inside
General medical imaging technique to look inside of a patient’ body
Standard CT system
Background
Motivation
 CT machines take much time(15~20min) and real-time operation is a
challenging issue.
 A huge system has been required for scanning mechanism since the
first invention.
The first inventor of CT, Hounsfield
(Nobel Prize winner, 1979)
Hounsfield’s sketch
CT Development History
No scan
th
Compact
Safe
5 ?
14stth
2:ndLinear
spiral
3:rdMultiple
: Fan-beam
CT
& rotational
orscanning
helical
CT CT
CT
CT
Concept for Non-scanning CT
Concept of future wearable CT
machines
A sketch of a next generation CT
for next Nobel Prize
Comparison between current and conceptual CTs
State-of-the-art CT
(Aquilion ONE )
Toshiba Medical System, 2006
Conceptual diagram of ascan-free CT
For real-time 3D reconstruction
Related Technique
Shield Field Imaging (Douglas Lanman, Ramesh Raskar et al. [2008] )
 Shadow-based 3D reconstruction by a single shot image
 Limitation : impossibility to local concave and backside shapes
A single shot image
Shield Field system
3D Reconstruction
Decoupling to multi-view images
Related Technique
Tomographic Reconstruction of Transparent Objects
( Borislav Trifonov et al. [2006] )
3D reconstruction of a transparent object by tomography
using 72~360 captured images
 Limitation : Requirement of moving system and many captured images
Capturing System
A glass object
One of 360 images Reconstruction Result
Experimental System
6~16 LEDs and a translucent object are used here.
Canon EOS 450D
(12M pixels)
Schematic diagram of system
150x100 pinhole array
(pinhole diameter of 428 microns)
Actual system
Non-scanning CT based on light field capturing
3D Reconstruction of transparent objects using visible
light with a single shot photo
 Limitation : 3D reconstruction in low resolution because decoupled multiview images are in low resolution, 80x80
A single shot photo
Single shot CT for a
translucent object
3D shape Reconstruction
Decoupling to multi-view images
Decoupling Process
A Single shot LF image
Decoupled multi-view images
Decoding process of a coded 4D light field image
Background Elimination
Elimination of background

Reference Images
3D Reconstruction by ART
Volume Reconstruction by ART
(Algebraic Reconstruction Technique)
5 multi-view Images
Experimental Results
Multi-view images(resolution is 100x200)
3D reconstruction results