SNM99SimultaneousPET_SPECT

1
Kinetic Modeling
Edward Di Bella Dmitri Riabkov Harshali
Bal Sathya Vijayakumar
2
Outline
Introduction to kinetic modeling Challenges 1.
Formulation/selection of physiological model 2.
Obtaining accurate input functions 3. Noise
issues - optimal data groupings 4. Noise issues -
optimal reconstruction, non-linear optimization,
use of constraints Applications
3
Introduction

• Examples of tracer kinetics
• Intravascular (99mTc-albumin, MS-325)
• Extracellular (gadolinium-DTPA)
• Intracellular (99mTc-Sestamibi, 99mTc-Teboroxime)
• More complex uptake and washout characteristics,
• including changes of state, binding (18FDG)

4
Semi-quantitative Models

• Area under curve
• Upslope
• Percent Enhancement

5
Two Compartments

Tissue - Interstitial (ve)
k
capillary
Vascular - plasma
Vascular - red blood cells
E extraction, F flow, t time volume
of extravascular space
6
Axial concentration gradient

Tissue
capillary
Vascular - plasma (Cp)
Vascular - red blood cells (Hct)
7
Model with capillary transit time
8
Canine Study (LAD occlusion)
9
Myocardial Perfusion with Contrast MRI
Region number
(e)
(d)
10
Infarct - volume of distribution changes

Tissue - ve
Vascular - plasma (Cp)
Vascular - red blood cells
Normal
Infarct
11
Myocardial viability
12
MRI and PET Viability

• (Upper panels) Non-viable apical region shown
  with FDG-PET, left, and contrast enhanced MRI,
  right. (Lower panels) Non-viable inferoposterior
  region shown with FDG-PET, left, and contrast
  enhanced MRI, right. Arrows indicate regions of
  non-viability.

13
Input Function - challenges

• MRI
• Saturation
• Flow effects

• Dynamic PET and SPECT
• Blood binding
• Temporal sampling rate
• Solution Blind estimation of kinetic parameters

14
Static SPECT
Dynamic SPECT
20-30s
90-100s
490-500s
290-300s
15
(No Transcript)
16
(No Transcript)
17
(No Transcript)
18
SUMMARY

• Kinetic modeling is a very useful approach with
  many applications
• Numerous important and interesting research
  areas
• Acquisition
• Automated robust processing
• Input function
• Modeling
• Visualization and use of parametric images