Goals of this presentation

Transcription

1 Transferring HEP Innovative concepts of electronics, trigger and DAQ Architecture for future large experiments to state of the art applications in medical imaging. P. Le Dû DEC_2010 1

2 Goals of this presentation A flavor of valorisation of Particle Physics R&D common to the medical imaging field Can we use what we are developping for future experiments in another field? This is not a competition with the medical imaging industry but a realistic demonstration of beyond the State of the Art technologies Illustrate using the example of Clinical imaging for tumor cancer Diagnostic :Whole: body Positron Emission Tomography Therapy :Real Time dosimetry in hadrontherapy My experiences of NA3 (SPS),OPAL(LEP),SDC (SSC),ATLAS (LHC), DO (FNAL),ILC DEC_2010 2

3 About PET DEC_2010 3

4 Positron Emission Tomography principle A Fonctional imaging using molecular tracers with doped beta + emitters The most common 18 F => 18 FDG fluoro-deoxy-glucose Annihilation positron with an electron Emission of two 511 kev photons back to back Sign the degree of activity of an organ hungry of glucose ---> show abnormal glucose metabolism like cancer tumour cells Colon cancer spots DEC_2010 4

5 Source of errors in the source Random coincidences Random True 25% Compton scatter Dector in coincidences Energy window around 511keV Time window few ns Scatter Signal : true concidences Background: Compton + Random Efficiency 0,01 (1 photon / 100) DEC_2010 5

6 Evolution of PET C-PET Philips First Steps Townsend & Jeavons First mouse imaging with 18 F 2007 Biograph PET + X ray-ct DEC_2010 6

7 HEP & PET Similarities and differences Calorimeter HEP CMS PET Camera Biomedical Imaging Similarities Geometry and granularity Detector (Crystals & scintillator) Sensor (PM,APD) Electronics:Fast (40 MHz), compact Data volume (Gbit/s) Differences Energy range (10GeV-511keV) No synchronisation --> free running electronics Multiple vertices Event Rate 10 MHz 28,700 ph/mev ER = 10.1% Energy (kev) DEC_ Counts

8 Common Areas Material for photon detection Standard :Crystal: Possible alternatives: LXenon, MG-RPC s,sampling calorim. Photon detectors Standard : PMT ---> MAPMT, MCP Semiconductor : APD --> SiPM/MPPC Front end electronics & signal treatment Fast, integrated, low noise, low power, self trigger Digital filtering and signal analysis --> TOF Trigger & DAQ Pipeline and parallel read-out, Real Time selection and treatment High bandwidth networks Computing Reconstruction, simulation & modelling DEC_2010 8

9 Counting rate estimate Every 10 ns 100 MHz 5,5 Every 100 ns 1,5 x 20 0,08 x 100 DEC_2010 9

10 Minute PET/CT The Physician Dream Combined whole-body PET/CT or PET/MR.. PET Courtesy of D.Townsend Less dose Less movment correction Screaning capability MDCT PET PET CT PET/MR PET Insert with Semiconductor photodetectors (S.R. Cherry, 2006) Magnet PET PET Magnet PET MR DEC_

11 The Challenge Whole-Body High-Resolution minute PET Very large number of channels (20 80 cm FOV) ~ 300 k channels (2x2 mm2 pixels) High trigger rate ~ 10 MHz (10 mci, 20% sensitivity) High data rate ~ 10 Gbyte/s (1 kbyte event size) Large number of events Looks like ~ 10 9 events (10 6 voxels, 1000 events/voxel) Large data volume per image ~ 1000 Gbytes (list mode) Real Time analysis Simultaneous merging of multimodality data CT- MRI DEC_

12 Back to PET DEC_

13 Next Time-of-Flight in medical PET c = 30 cmt/ns 500 ps timing resolution 7,5 cm localization Can localize source along line of flight. Time of flight information reduces noise in images. But LOR ---> list mode δt (ps) Δd (cm) SNR* Objective : < 100 ps Timing Resolution (global) (30-50 psec for the electronics) Conventional * SNR gain for 40 cm phantom = SNR TOF / SNR non-tof Conventional 300 ps Simulation of liver cancer DEC_

14 Gemini TF Advantage of TOF LYSO 4 x 4 x 22 mm 3 (LYSO) 3D only (no septa) Brilliance 16 CT 70 cm port 18 cm axial FOV 585 ps timing Courtesy Joel Karp PhD, University of Pennsylvania Non-TOF TOF 60 s scan duration Rectal carcinoma, with metastases located in the mesentery and bilateral iliac chains more clearly seen with TOF. 114 kg; BMI = mci; 2 hr pi 3min/bed position Non-TOF TOF DEC_

15 Exemple of Conceptual TOF-PET architecture model PMT Front End clock Read-Out/DAQ crystal MCP SiPM PA SH Gbit Sampler & pipeline Digital Filter BUFFER ROI Data Pixelated Fast Low noise Low power Pulse Shape Digitizer E,T,Q Software Trigger Real Time TOF treatment Free-running analog waveform sampling and digitizer (SCA) Digital filter used to extract pulse amplitude and high resolution timing (FPGA) Pipelined processing architecture to avoid deadtimes Parallel digital read out Terabit network for communication and processing (xtca) DEC_

16 DAQ = Pipeline Architectures LHC Future PET Digitisation Pipeline Event builder DEC_

17 Synchro W1 «Advanced» TEP TOF Data Flow W2 W3 W4 Front End DUAL Buffer W5 W6 W7 W8 Front End Signal processing & digitization no trigger interrupt Active pipeline and Dual Local Buffer Event manager & Control 1 Wedge Buffering Event Building Network P P P P P P P P Processor farm (one time window per processor) Data Steams Logger and Mass Storage xx Gbit/sec P P?KHz xx Mbyte/sec Read Out Node Wedge Buffer Processing Sofware Selection of Event Of Interest Event building,tof Classification and analysis according to selected criterias Storage DEC_ ms few ms Sec?

18 In Beam PET for Real Time dosimetry for Hadrontherapy DEC_

19 Hadrontherapy accelerators the rationale 200 MeV - 1 na protons 4800 MeV 0.1 na carbon ions which can control radioresistant tumours 27 cm charged hadron beam that loses energy in matter tumour target DEC_

20 In beam Time-of-Flight PET for treatment planning and monitoring PET camera Carbon ion beam will induce 11 C after collision with cell DNA 11 C is a β + emitter which can be used for online PET imaging 11 C activity profile correlated with dose profile: measure β + profile to reconstruct true dose profile and check against planning Carbon beam Positron emitters are produced in situ by the carbon beam DEC_ Courtesy K.Parodi 20

21 Clinical GSI implementation Use a dedicated TEP heads to monitor dosimetry and compare with simulation But : low true coincidences and NO Real Time Extractio n P A 2 B 2 W. Enghardt FZ Rozendorf /GSI DEC_

22 Clinical results at GSI Range verification in delicate situations: Stopping of the beam in front of organ at risk DEC_

23 In Beam PET principle Use beta emitting nuclei from beam projectile reactions in the biological matter Schematic Set up Beam measurement particle by particle Deadtimeless Front End electronic On line selection of the 2 photons (trigger) Real Time TOF measurement Optional INNOTEP - IN2P3 project FP7 ENVISION project Upenn/IBA project DEC_

24 Summary & Conclusion HEP has considerable acquired knowledge, expertise and resources that can, when transferred properly, significantly impact the practice of medical imaging and therapy About technology transfer Understanding the problems in both sides is essential Successful technology transfer can result An expansion of established application An improvement of current performance levels A more beneficial cost/benefic ratio More on TOF PET ---> Picosecond website Thanks for your attention DEC_

25 Thanks to W. Enghardt ( F.Z. Rozendorf) H. Frisch ( U. Chicago) J.F. Genat (U. Chicago) J. Karp (U. Penn) P. Lecoq ( CERN) W. Moses ( LBL) G. Montarou (LPC Clermont) D. Townsend ( U. Tennessee) J. Varela ( LIP) DEC_