Next Generation CAT System

Non-scanning CT (computerized tomogra-phy)

Standard CT system

CT(computerized tomography) creates 3D views of what is in-side

General medical imaging technique to look inside of a patient’ body

Background

· CT machines take much time(15~20min) and real-time opera-tion is a challenging issue.· A huge system has been required for scanning mechanism since the first invention.

Motivation

Hounsfield’s sketchThe first inventor of CT,

Hounsfield(Nobel Prize winner, 1979)

CT Development History

1st : Linear & rotational CT

2nd : Multiple scanning CT

3rd : Fan-beam CT

4th: spiral CT or helical CT

5th ?No scanCompact

Safe

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, 2006Conceptual 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

Decoupling to multi-view im-ages

3D ReconstructionShield Field system

Related TechniqueTomographic Reconstruction of Transparent Ob-jects ( Borislav Trifonov et al. [2006] )

A glass object

·3D reconstruction of a transparent object by tomography using 72~360 captured images Limitation : Requirement of moving system and many captured images

One of 360 imagesReconstruction Result

Capturing System

Experimental System

Schematic diagram of sys-tem

6~16 LEDs and a translucent object are used here.

150x100 pinhole array (pinhole diameter of 428 mi-

crons)Actual system

Canon EOS 450D(12M pixels)

Non-scanning CT based on light field captur-ing3D Reconstruction of transparent objects using visible light with a single shot photo

· Limitation : 3D reconstruction in low resolution because decoupled multi-view images are in low resolution, 80x80

A single shot photo

3D shape Reconstruction

Decoupling to multi-view im-ages

Single shot CT for a translucent object

Decoupling Process

Decoding process of a coded 4D light field image

A Single shot LF image Decoupled multi-view images

Background Elimination

Elimination of background

Reference Images

3D Reconstruction by ART

Volume Reconstruction by ART(Algebraic Reconstruction Technique)

5 multi-view Images

Experimental Results

3D reconstruction results Multi-view images(resolution is 100x200)