Xray and Gamma ray Medical Imaging Applied Technologies oriented perspectives Jean ROUX - Hamamatsu Photonics France Oct 8 th 2014
Presentation Outlines Introduction & context of the presentation X-ray Imaging (CMOS / CCD / Flat Panels) Gamma ray Imaging ( PMTs / MPPC ) Conclusion & References
Hamamatsu Photonics Business Model KEY PARTNERS KEY ACTIVITIES & RESSOURCES VALUE PROPOSITION CHANNELS MARKETS R&D ( 10,6% in 2013 ) Direct and Distribution Large Diversification NOT LISTED HERE SIGNIFICANT PRODUCTION CAPABILITIES Research and Industries but IMPORTANT PATENTS PORFOLIO : Components HOPEFULLY SOME OF YOU Vaccuum Devices Tubes technologies PHOTON IS OUR BUSINESS Modules including Opto-Semicondutors Devices technologies Instrumention XRAY and GAMMA Medical Imaging Low Noise electronics developpment Equipment System Integration COST STRUCTURES in 2013 REVENUS STRUCTURES in 2013 1 B$ NET SALES / NET Income 11,3% Source : Hamamatsu Photonics K.K Japan Open Sources- ETD & SSD Handbooks-Annual Report2013
Hamamatsu R&D and Production facilities Source: Hamamatsu Photonics K.K Japan Open Sources- ETD & SSD Handbooks-Annual Report2013
Imaging without limit : Water or Wafer? Source : Hamamatsu Photonics K.K Japan Open Sources- ETD & SSD Handbooks-Annual Report2013
Medical Imaging : The challenges Source : F.Glasser-«Imaging breakthrough for health applications»-cea LETI Grenoble- LETI Days June 2014
Xray & Gamma ray Imaging mind mapping Source : Hamamatsu Photonics K.K Japan Open Sources- ETD & SSD Handbooks-Annual Report2013
X-ray Imaging (CMOS / CCD / Flat Panels)
Keys points adressing detectors technologies challenges Detectability Index : d². This model is predicting the detectability of the signal over the noise (B) ΔS/B : term describing the difference between a healthy «object» and same «damaged» object, reported to the noise, for a given spatial frequency f. This term is concerning the «pathology» Dose : Determined by the radiologist, in respect of the tissues ( Xray tube kv / mas adjustment ). The detectability is proportionnal to the squarred root of the dose(!). DQE : Detective Quantum Efficiency. This term is concerning the «detector + scintillator» expressing its impact on the S/N between the input and the output of the detector for each frequency. For a given level of requested detectivity at a given frequency ( decided by the radiologist), the improvement of the DQE leads to Dose reduction ( Safer Situation for the Patient ) DQE curves : Dependency on Spatial frequency, on Detector type, on Pixel size MTF (Sinus) / CTF(Squarred) : Modulation and Contract Transfert Functions. The pixel stucture ( Passive or Active and its size ) are determining the spatial resolution, sensitivity and electronic noise performances at first. In addition, the choice of scintillator, its thickness, and its assembly on detector are determining the DQE and also the spatial resolution and sensitivity Final target, for one type of pathology ( type of object and its tickness ) consists to get the highest DQE for reducing the necessary Dose, in combination with the highest detectability level for a given spatial frequency. The size of the «object» is determining the size of the detector Field Of View. (DR and CT Scanner) Sources : Please refer to sourcing n 1 and n 11 on last slide.
Pixels Structure & Scintillators challenges Pixels Structures CMOS Passive Pixel Merits Disavantages One amplifier / each column Adressing pixel / adress switches connected to amplifier Amplifier arrays High fill factor High radiation durability Amplifier thermal noise Active Pixel Structure lowering the noise ( 1/6 passive pixel ) One amplifier / each pixel High S/N features High definition images from low energy Xrays CCD High fill factor Cost Lower noise Radiation durability High S/N features a-si Low cost per area Time response Large area per device Uniformity Large pixel structure only Source: Hamamatsu Photonics K.K Japan Open Sources- ETD & SSD Handbooks-Annual Report2013
Pixels Structure & Scintillators challenges Scintillators Structures Source: Hamamatsu Photonics K.K Japan Open Sources- ETD & SSD Handbooks-Annual Report2013
Pixels Structure & Scintillators challenges Scintillators Structures Source: Hamamatsu Photonics K.K Japan Open Sources- ETD & SSD Handbooks-Annual Report2013
Gamma ray Imaging ( PMTs / MPPC )
SPECT or PET imaging? Molecular Gamma Imaging Radioisotopic Probes ( ex.) Scintillator type (ex.) SPECT Technetium 99 A "gamma" camera Iode 123 NaI (Mono Photon) Indium 111 PET / TOF PET BGO A "positrons" camera Fluor 18 GSO (Bi Photons) LSO, LFS, The molecular marking through a Gamma emitter, or a Positrons emitter is driven by the chemical and biological properties of the specific best molecule addressing the pathology process under survey. Exemple : The Fluor 18 is often used through the FDG molecule which is excellent for glucose metabolism survey ( Tumoral cells over consume glucose ) Source : C.Comtat SHFJ CEA Orsay Imagerie moléculaire en tomographie par émission de photons Journée Sciences Physiques et technologies pour le vivant et la santé 2008 Source :Hamamatsu Photonics K.K Japan Open Sources- ETD & SSD Handbooks-Annual Report 2013
PET / TOF PET : a MPPC perspective (not excluding PMTs and APDs others approaches) Source : Please refer to sourcing n 1, n 2 and n 4
Mode of acquisitions : 2 conditions Double 511 kev energy ( Energy spectroscopy ) Time of coincidence ( Timing resolution )( Suppress the collimator needs ) Source : Please refer to sourcing n 1, n 4
Understanding some challenges with conventionnal PET Spatial resolution caused by the physics ( Annihilation distance, co-linearity divergence, scintillator sizing ) Absorption ( One of 2 gamma is absorbed by the media ) Diffusion ( Compton diffusion imples direction changing / energy spreading ) Random coincidences Non transversal uniformity ( related to non perpendicularity of LOR versus Crystal entrance face. ) Source : J.S. Lee Technical Advances in Current PET and Hybrid Imaging Systems The open Nuclear Medecine Journal, 2010, 2, 192-208
Merits and Importance of Time of flight TOF PET Confine area around estimated annihilation position Coincidence timing resolution : an important determinator of the degree of artifacts reduction Source : Please refer to sourcing n 2, n 4
MPPC structure and Scintillators challenges Scintillators challenges for TOF PET: LFS merits - High Z and high density for minimum braking distance (attenuation lenght ( improvement of depth of interaction ) - Reducing the decay constant to optimise the total time resolution. Source : Zecotek LFS White Paper- «Enabling the future of imaging and detection - 2011
MPPC : Multi-pixel photon counter with Geiger Mode APDs Source : Hamamatsu Photonics K.K Japan Open Sources- ETD & SSD Handbooks-Annual Report2013
Pictures Source : Hamamatsu Photonics K.K Japan Open Sources- ETD & SSD Handbooks-Annual Report2013
Design and Performance (1/3) Source : Hamamatsu Photonics K.K Japan Open Sources- ETD & SSD Handbooks-Annual Report2013
Design and Performance (2/3) Source : Hamamatsu Photonics K.K Japan Open Sources- ETD & SSD Handbooks-Annual Report2013
Design and Performance (3/3) Source : Hamamatsu Photonics K.K Japan Open Sources- ETD & SSD Handbooks-Annual Report2013
MPPC Design driving PET performances MPPC Features driving Devices performances Linearity After Pulses Photodetection Efficiency Dynamic Range Time resolution Crosstalk Gain Time resolution Crystal Choice MPPC Design driving PET / TOF PET performances Number of pixels Crystal defects Wafer process performances Filling Factor / TSV design Operating Voltage Filling Factor Pixel pitch sizing Spatial resolution Quenching Resistor Material Operating Voltage Through Silicon Vias ( Wiring lenght) Spatial Resolution Depth Of Interaction Time resolution ( Decay time ) Environnement Magnetical Proof ( MRI ) MultiModalities Source : Hamamatsu Photonics K.K Japan Open Sources- ETD & SSD Handbooks-Annual Report2013
Conclusion Fine Tuning among : 1. Multimodalities approach ( morpho + functionnal + type of medias to observe ) 2. Spatial resolution 3. Just enough dose rate for the patient 4. Field of view ( vs pathology to survey ) 5. Capex and Cost of Ownership for final customer 6. Design for Business model for type of usage ( rental or capex model? )( design for usage ).(rental : a consummables approach / capex : a maintenance approach ) Source : Hamamatsu Photonics K.K Japan Open Sources- ETD & SSD Handbooks-Annual Report2013
Back up slides & Informations sourcing
Medical Imaging : Market and Multimodalities Source : P.Frent «Global Medtech Companies»-Market Analysis XERFI /Global- August 2011
Medical Imaging : Market and Multimodalities Source: F.Glasser-«Imaging breakthrough for health applications»-cea LETI Grenoble- LETI Days June 2014
DQE and FTM/CTF considerations Driving the Pixels Technologies and Pathologies suitabilities Sources : Please refer to sourcing n 1,n 11,n 13 on last slide.
Short detectors review for SPECT : a PMT s perspective (not excluding APDs nor Si PMTs possible approaches) Source : C.Comtat SHFJ CEA Orsay Imagerie moléculaire en tomographie par émission de photons Journée Sciences Physiques et technologies pour le vivant et la santé 2008 Source :Hamamatsu Photonics K.K Japan Open Sources- ETD & SSD Handbooks-Annual Report 2013
Operation of R8900-C12 Position Sensitive PMT with Cross Wire (Plate) anodes Position is calculated by Center of Gravity Method. Source :Hamamatsu Photonics K.K Japan Open Sources- ETD & SSD Handbooks-Annual Report 2013
Collimators and Energy spectroscopy Source :Hamamatsu Photonics K.K Japan Open Sources- ETD & SSD Handbooks-Annual Report 2013
High Photon Detection Efficiency (PDE) Metal Quenching Resistor Uniform and stable resistance Low temperature dependence High transparency for visible light High fill factor = High PDE Small pixel pitch is also available (10μm, 15μm) Improved Metal quenching resistor Previous Quenching resistor (Poly-Si)
Through silicon via technology (TSV) No wire bonding Decreasing the dead area TSV 4-side buttable package Very large detection area. TSV size (0.4% against active area) for 3x3mm 2 device
Informations & bibliography sourcing 1. Hamamatsu Photonics K.K Japan Open Sources- ETD & SSD Handbooks-Annual Report2013 2. J.S. Lee Technical Advances in Current PET and Hybrid Imaging Systems The open Nuclear Medecine Journal, 2010, 2, 192-208 3. A.Del Guerra University of Pisa Advances in Position Sensitive Photodetectors for PET applications - 8 th International conference on Position Sensitive Detectors 4. C.Comtat SHFJ CEA Orsay Imagerie moléculaire en tomographie par émission de photons Journée Sciences Physiques et technologies pour le vivant et la santé 2008 5. I.Buvat «Tomographie d émission monophotonique et tomographie d émission de positons» - U678 INSERM Paris-2006 6. O.Peyret et als «Vers les gamma-caméras à semi-conducteurs»- CEA LETI Grenoble- Revue de l ACOMEN, 1999,vol5,n 2 7. J.A.Seibert «Digital radiography CR versus DR?Time to reconsider the options, the definitions,and current capabilities»-applied Radiology December 2007 8. I.Buvat- L imagerie moléculaire multiparamétrique et ses défis méthodologiques -UMR 8165 CNRS Paris- Avril 2013 9. F.Glasser-«Imaging breakthrough for health applications»-cea LETI Grenoble- LETI Days June 2014 10. M.Kroning et als- X-Ray Imaging Systems for NDT and General Applications -Fraunhoffer Institute Dreden- NDE 2002 11. JM Vignolle et als Les paramètres importants d un capteur plan (DR) pour la reduction de dose - TRIXELL Grenoble SFR Paris Mars 2012 12. Zecotek LFS White Paper- «Enabling the future of imaging and detection - 2011 13. G.Roos- Amorphous Silicon Pixels Detectors for Radiography -VARIAN 14. I.Buvat- Quantification en imagerie hybride:les enjeux de l IRM-TEP -UMR 8165 CNRS Paris- Journées Francaises de Radiologie Octobre 2013 15. P.Frent «Global Medtech Companies»-Market Analysis XERFI /Global- August 2011