Prof. Stefaan Vandenberghe Enrico Clementel MEDISIP Prof. Stefaan Vandenberghe Enrico Clementel

NEUROLOGY EEG MR NEUROLOGY UROLOGY NUCLEAR MEDICINE ONCOLOGY NEUROLOGY Spike detection NEUROLOGY EEG Artefact removal Dipole localisation MR Reconstruction Spectroscopy Diffusion imaging NEUROLOGY UROLOGY NUCLEAR MEDICINE Reconstruction Hardware Simulations ONCOLOGY NEUROLOGY CARDIOLOGY steven.staelens@ugent.be – Medical Genetics meeting – 4/7/2007

Related expertise for this project build up in other projects steven.staelens@ugent.be – Medical Genetics meeting – 4/7/2007

Monte Carlo simulations Medisip-UGent: OpenGate collaboratie ( > 30 universities), simulation code based on GEANT4 Accurate simulation source, object, PET/SPECT system Belang Development of new prototypes Study of image degrading effects steven.staelens@ugent.be – Medical Genetics meeting – 4/7/2007

Monte Carlo simulations: Image reconstruction The final main track is image reconstruction. We provide state-of-the-art image reconstruction packages for SPECT and PET. Mainly also using Monte Carlo simulated system matrices. This is important for quantification, dosimetry, and radionuclide therapy. stefaan.vandenberge@ugent.be – MIT – 8/10/2007 steven.staelens@ugent.be – Medical Genetics meeting – 4/7/2007 5 5

Hyperimage: simulation of PET/MR test systems Build-up of a PET system based on modular detector approach of WP1 PET-Detector simulation System design and development PET-compatible animal and whole body RF coils and RF shielding Minimization of the interference between the two modalities, to facilitate simultaneous image acquisition

Hyperimage: Novel Algorithms for Motion and Attenuation Correction Improvement of the PET image quality by using concurrently acquired MR image data for patient motion correction Integration of motion correction with the acquisition of complementary functional information from PET and MR Investigation of robust PET attenuation correction methods based on MR data Development of data analysis and visualization for multidimensional PET/MR data

PET systems with better image quality DT = 500 ps ~ 7.5 cm DT = 4 ns non-TOF TOF CT steven.staelens@ugent.be – Medical Genetics meeting – 4/7/2007

Commercial system (collaboration with Karp/Surti UPENN) PET scanner LYSO : 4 x 4 x 22 mm3 28,338 crystals, 420 PMTs 70-cm bore, 18-cm axial FOV CT scanner Brilliance 16-slice Philips Gemini TF Energy resolution: 11.5% fwhm, Timing resolution: 585 ps NEMA NU-2 Spatial resolution: 4.8 mm at 1cm Sensitivity: 6.6 cps/kBq Scatter fraction at 440 keV: 27% for 20-cm x 70-cm Peak NEC: 125 kcps @ 0.42mCi/ml

Fast reconstruction with SSRB-TOF this term adds a TOF based correction to Single Slice ReBinning (SSRB) FORE-TOF also possible: Michel Defrise, PMB 2005

20 mm spheres 10 mm spheres SSRB-TOF (424 ps) 3D listmode SSRB-TOF 1. Introduction 2. TOF-PET 3. TOF reconstruction 4. Image quality gain 5. Conclusions SSRB-TOF 20 mm spheres SSRB 10 mm spheres 3D listmode SSRB-TOF SSRB 25 cm

SSRB-TOF:axial resolution loss 1. Introduction 2. TOF-PET 3. TOF reconstruction 4. Image quality gain 5. Conclusions

determine position in histoprojection Mashing Mashing = Reducing number of projection angles by combining close LORs 1. Introduction 2. TOF-PET 3. TOF reconstruction 4. Image quality gain 5. Conclusions TOF-Mashing makes use of the most likely point to determine position in histoprojection *Fast reconstruction of 3D TOF PET data by axial rebinning and transverse mashing S.Vandenberghe et al., Phys. Med. Biol. 51 No 6 2006, 1603-1621

Filtered Backprojection of PET-data Mashing 20 angles Filtered Backprojection of PET-data 40 angles 1. Introduction 2. TOF-PET 3. TOF reconstruction 4. Image quality gain 5. Conclusions Confidence Weighted Backprojection of TOF PET 300 ps = 45 mm 5 angles 8 angles 3 angles

kernel truncation (used for speedup recon)

steven.staelens@ugent.be – Medical Genetics meeting – 4/7/2007

TOF resolution depends on countrate ! Clinical range Measurements Ugent-UCL

Correct TOF resolution needed for correct recon ! Phantom Simulations Ugent, presented at IEEE MIC 2007

steven.staelens@ugent.be – Medical Genetics meeting – 4/7/2007

Proposal of Ugent tasks in Envision Simulations of best geometry (limited angle or axially tilted) Corrections in software (time offsets, poster Enrico Clementel) Reconstruction of limited angle data (system matrix based) Physics PhD candidate from US interested for Envision steven.staelens@ugent.be – Medical Genetics meeting – 4/7/2007