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Contents
Principle of PET Measurement.
– PET: Positron Emission Tomography

Teleradiology for Remote Quantitative
Analysis of PET

Static and Dynamic Scans.
– Qualitative and Quantitative Analysis.

Number of PET imaging systems and Experts.
Teleradiology System.
Proposed System.
Summary.

Mika Naganawa
Image Processing Laboratory
October 28, 2004

COE presentation, October 28, 2004

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Principle of PET Measurement

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Principle of PET Measurement

Tomographic image of a distribution of radioactive
pharmaceutical.

Example of pharmaceutical.

glucoseradioactive
pharmaceutical

gamma rayβ + decaygamma
rayradioactive isotope

cancer cell

COE presentation, October 28, 2004

normal cell

COE presentation, October 28, 2004

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Static and Dynamic PET Scans
Static PET scans

Dynamic PET scans
Serial arterial blood sampling

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Qualitative Analysis
PET images are VISUALLY analyzed by looking for
local differences in uptake in the regions imaged.
– Non-producible and subjective evaluation.
X-ray CT
MRI

PET

0.3 1
Qualitative analysis(Visual inspection)

Quantitative analysis(Compartment model)

COE presentation, October 28, 2004

Spatial reso

4lution[mm]8COE presentation, October 28, 2004

1Oct. 28, 2004

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Quantitative Analysis

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Quantitative Analysis

Physiological parameters are calculated based onmathematical model.

Mathematical Model– Physiological parameters are estimated voxel-by-voxel or
ROI-by-ROI.

Cerebral metabolic
rate of glucose

Clinical Image
K1

k3

k2

Activity

CMRGluEstimations
Time
COE presentation, October 28, 2004

COE presentation, October 28, 2004

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Quantitative Analysis

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Qualitative and Quantitative analysis

Mathematical Model

Qualitative analysis.

Clinical Image

Activity– Take less time.
– Subjective and non-reproducible evaluation.
– Skillful doctors.
Parameter Estimate
Estimate
Parameter

K11k22k33

Quantitative analysis.

0.1
0.2
0.1
0.03
0.07

– Much computation time.
– More objective.
– Relies less on doctor’s judgments.
– Serial arterial blood sampling.
– Skillful doctors and modelers.

Time250,000 voxels
20sec/voxel

Calculation time: 5~6 days

COE presentation, October 28, 2004

COE presentation, October 28, 2004

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Number of PET and Experts
72 Institutions (at Oct. 8, 2004).
Approximately 100 imaging systems of PET

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Teleradiology SystemDoctor-net, Hospi-net.
Image
Image archiveand storage
Static PET scannetwork
ReportDiagnostic
workstation

Number of medical specialists
COE presentation, October 28, 2004

Remote Medical Facility

Diagnostic
workstation

Reading

Expert Medical Site

COE presentation, October 28, 20042Oct. 28, 2004

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Practical issues

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Proposed System (Proposal)

Omission of arterial blood sampling
using statistical separation.
Reduction of computation timeusing clustering analysis.

Construction of Database
Dynamic
ImagesDynamic PET scans
With or without blood sampling

Estimation

Diagnostic
workstation

Remote Medical Facility
COE presentation, October 28, 2004

Data archiveand Storage

network
ReportParametricimages

Diagnostic
workstation
Blood curve estimation
Quantitative analysis

Expert Medical Site

COE presentation, October 28, 2004

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Summary
Quantitative analysis will provide more objective
interpretation of PET images, however it requires muchcomputation time and serial arterial blood sampling.
Radiologists and modelers are very small in number.
Teleradiography system for quantitative analysis of PET
images is proposed.

COE presentation, October 28, 2004

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