PET Activities at UiO NFR Review 16.04.2009 E. Bolle* *erlend.bolle@fys.uio.no

Outline PET intro AxialPET Beyond AxialPET Concept Implementation Results Beyond AxialPET Continuation Financing Partners

Positron Emission Tomography Medical technique for imaging functional processes in the body Show areas with high metabolic activity (cancer) Inject biologically active molecules tagged with radioactive tracers -> F-18, C-11, O-15….. Detects pair of 511keV gammas (LOR) Reconstruct 2D/3D images

Axial PET A Novel PET Detector Concept with Full 3D Reconstruction AX-PET* collaboration * INFN Bari, Ohio State University, CERN, University of Michigan, University of Oslo, INFN Roma, University of Valencia, PSI Villigen, ETH Zurich

Challenge Measure DOI (Depth Of Interaction) No depth of interaction information → Parallax error! Solution: Measure interaction point in 3 dimensions Parallax error: Increase with distance from center of FOV

Axial PET Geometry

Axial PET Concept LYSO gives x-y + energy WLS derive axial (z) position Readout on one end of WLS and LYSO. Reflector on opposite end Light below angle of total reflection escapes LYSO → absorbed at one side by WLS Light transport relies on internal reflection → Polished and crack-free surface Resolution along the three dimensions can be tuned varying LYSO/WLS dimensions https://twiki.cern.ch/twiki/bin/view/AXIALPET/WebHome

Main Components LYSO 1.19x3.22mm2 MPPC 3x3mm2 MPPC WLS

Demonstrator 2 LYSO matrices of 8x6 crystals 312 WLS 3×3mm2 MPPC for LYSO 1.19×3.22mm2 MPPC for WLS Mechanics for support and cooling (water) Readout electronics on bottom WLS LYSO 3x3mm2 MPPC 1.19x3.22mm2 MPPC

Simulation & Image Reconstruction Simulation studies are done to optimize demonstrator and improve understanding Geant4 and Gate simulation software Dedicated image reconstruction software is under development to optimize image quality with the new geometry

Results 2 layers assembled Acquired with a 22-Na source Data from 2 layers of LYSO Dato from one layer of WLS

Status All components tested show satisfying performance for an AxialPET Parts for 2 modules Demonstrator with two detector being assembled: Electronics is developed Mechanics is produced All components procured First results in 2009 One almost assembled

Beyond AxialPET……

Funding Partners Approved a 4 year PET research program through FRITEK FRITEK is a NFR-program Financing for equipment, travel and 2 positions for the project period 1 Ph.D. (3 years) 1 Researcher (3 years) Equipment should cover what’s needed to build a complete animal PET scanner Funding until end 2012 Radiumhospitalet MRI machine available and one of the few human PET scanners in Norway Small Animal Unit Part of Faculty of Medicine Already have an animal PET scanner AxialPET INFN Bari, Ohio State University, CERN, University of Michigan, University of Oslo, INFN Roma, University of Valencia, PSI Villigen, ETH Zurich

Schedule 2009 2010 2011 2012 Simulation Image Reconstruction Prototype Studies Fix Geometry Image Reconstruction Scanner Implementation Phantom Studies Scanner Implementation Phantom Studies Pre-clinical Tests Pre-clinical Studies

+ Goals Build a small animal PET system with 3D event reconstruction World class system performance MRI compatibility +

Ultimate Goal (a) Dynamically acquired PET images from a C57BL/6 mouse injected with [11C]-d-threo-methylphenidate show a specific dopamine transporter binding in the striatum (S) and nonspecific uptake in the Harderian glands (H). (b) Brain morphology is revealed from the magnetic resonance images simultaneously acquired using a 3D TSE sequence. (c) The fused images show enhanced tracer uptake, matching the morphology of the striatum in the magnetic resonance data. (d) Time-activity curves (TACs), derived from the PET data simultaneously acquired during MRI, allow further analysis such as kinetic modeling to determine the dopamine transporter binding potential. The clear separation of the striatum and cerebellum (Cb) curve indicates more specific tracer binding in the striatum than in the cerebellum. Both TACs include unbound tracer. Scale bars, 1 cm.

People and Publications Involved: S.Stapnes, E.Bolle, O.Rohne, O.Dorholt, P.Nordahl and J.I.Buskenes Publications 2008: IEEE MIC 2008: proceedings of the IEEE NSS MIC conference, Dresden (Germany) IPRD 2008: proceedings of the IPRD08 conference, Siena (Italy) NDIP 2008: proceedings of the NDIP08 conference, Aix-les-Bains SORMA (WEST) 2008: proceedings of the 2008 SORMA WEST conference