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OPTIMISING PET/CT AND SPECT/CT INVESTIGATIONS.
THE MADEIRA PROJECT.
Helena Uusijärvi, Marie Sydoff, Marcus Söderberg, Sigrid Leide-Svegborn and Sören Mattsson
Department of Medical Radiation Physics, Lund University, Malmö, Sweden
MINIMIZING ACTIVITY AND DOSE WITH ENHANCED IMAGE QUALITY BY RADIOPHARMACEUTICAL ADMINISTRATION
Assessment of clinical dataMalmö
Development of PET magnifier probeLjubljana, Valencia and Michigan
Physics-based image processingMunich, Göttingen and Malmö
Biokinetic and dosimetric modellingMalmö, Milan and Munich
ASSESSMENT OF CLINICAL DATA
Malmö
Collect biokinetic data
Send raw data from PET/CT to Munich
Reconstruction and noise reduction
Send CT data to Munich
Voxel phantoms
DEVELOPMENT OF PET MAGNIFIER PROBE
Ljubljana, Valencia and Michigan
Improve the spatial resolution
Improve detector efficiency
By Marko Mikuz
PHYSICS-BASED IMAGING PROCESSING
Munich, Göttingen and Malmö
Develop reconstruction algorithms
Noise reduction
Compare reconstruction algorithms
Speed
Resolution
Noise
Artefacts
BIOKINETIC AND DOSIMETRIC MODELLING
Malmö, Milan and Munich
Biokinetic
18F-methylcholine – Prostate cancer
123I-ioflupane (DaTSCAN) – Parkinson’s disease
Organ/patient doses
Optimal time scheme
MADEIRA IN MALMÖ
Biokinetics
Time scheme between injection and acquisition
Activity quantification
Reconstruction process
Respiratory gating
BIOKINETICS, 18F-METHYLCHOLINE
8 h4 h1 h0 h
PET/CT
PET PETPET
Blood BloodBloodBlood
Urine Urine Urine
T½,phys = 110 min
BIOKINETICS, 123I-IOFLUPANE
24 h3 h1 h0 h
SPECT/CT
SPECT SPECTSPECT
Blood BloodBloodBlood
Urine Urine Urine
T½,phys = 13 h
BIOKINETIC
ROI around organs with activity uptake
Blood/urine – gamma counter
Compartment model
ACTIVITY QUANTIFICATION
Verify values given by the camera
Counts
Activity
Activity per volume
SUV (Standardised Uptake Value)
ROI shape
Spillover effects
Attenuation correction
Reconstruction methods
TIME OPTIMISATION
123I-ioflupane
24 h3 h1 h0 h
SPECT/CT
SPECT SPECTSPECT
T½,phys = 13 h
RECONSTRUCTION PROCESS
SPECTFiltered Back Projection (FBP)Ordered Subset Expectation Maximization (OSEM)Flash 3DReSPECT
FBP OSEM Flash 3D
FBP VS FLASH 3D
FLASH 3D – 5 VS 30 ITERATIONS
RESPIRATORY GATING
Minimize respiratory motion artefacts
Improve small lesion detectability
Improve small lesion localisation
Improve accuracy of SUV (Standardised Uptake
Value)
RESPIRATORY GATING18F-FDG – tumours in lung region
NON-GATEDSUV = 3.9
RESPIRATORY GATEDSUV = 6.0
