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Spin-offs da Física de Partículas

"Explore the practical applications and contributions of ClearPEM PET-Mammography in simulating clinical scenarios, including breast brachytherapy, brain radiosurgery, and electronic processing. Learn about the components and types of imaging acquisitions, as well as the PET physics principles. Developed in collaboration with Crystal Clear Collaboration, the ClearPEM system allows for detailed breast and axilla examinations, with rotating detector plates and the ability to simulate and measure various intensities. The system also includes a PET robotic device and low-noise electronics for accurate detection and measurement."

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Spin-offs da Física de Partículas

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  1. Spin-offs da Física de Partículas Luis Peralta LIP/FCUL

  2. Ciência fundamental Aplicações práticas Contribuições de apresentações de Adérito Chaves Gonçalo Borges João Varela Mário David Patrick Sousa Sónia Rodrigues etc….

  3. Simulando situações com aplicação clínica Braquiterapia Mamária

  4. Radiocirurgia ao cérebro

  5. Electrónica e processamento Display PMTs Cristal Cintilador Colimador Câmara Gama

  6. Siemens E.Cam Dual Head [2] 2 cabeças de detecção (colimador, Cristal cintilador, Guia de luz, Matriz de PMTs) Angulação variável (180º, 90º e 70º) Tipos de aquisição: imagem estática, imagem dinâmica, imagem Tomográfica (SPECT) Descrição da Câmara Gama [2]http://www.medical.siemens.com

  7. Fantôma da Tiróide: Acrílico Nódulos quentes e frios Distância fonte–colimador: 5 cm Centrado no FOV Fantôma • Fantôma Simulado • Fantôma Real • Simulação • Medição Experimental Intensidades • Elipsóide#1 38.6 % • Elipsóide#2 54.0 % • Nódulo quente#2 7.4%

  8. Principio Físico do PET Emissão do positrão positrão+electrão 2 fotões Aniquilação

  9. Sensitivity@350 keV (%) 4 cm off-axis 3 cm off-axis Y-axis (cm) 2 cm off-axis 1 cm off-axis central slice X-axis (cm) Projecto ClearPEM Projecto desenvolvido no quadro da colaboração Crystal Clear Collaboration @ CERN • Consortium PET-Mammography, Portugal TAGUSPARK – Parque de Ciência e Tecnologia LIP - Laboratório de Instrumentação e Partículas Hospital Garcia Orta - Serviço Medicina Nuclear IBEB - Instituto Biofisica e Engenharia Biomédica IBILI - Instituto Biomédico de Investigação da Luz e Imagem INESC - Instituto de Engenharia de Sistemas e Computadores INEGI - Instituto de Engenharia Mecânica e Gestão Industrial • CERN, Geneva • VUB, Brussels

  10. ClearPEM Sistema de imagem Exames de mama e axila • Exames de mama com paciente na posição decubito • Pratos do detector rodam em torno da mama • Pratos podem ser rodados para exame da axila PEM Detector Plates PEM Robotic Device

  11. ClearPEM Detector • ClearPEM Detector: • Two detection plates • 192 crystal matrices (8x4 crystals each) • Front-back APD readout for DoI measurement Plate surface 14x16 cm2 • 6300 LYSO:Ce crystals • Avalanche photodiodes • Low noise electronics Optical simulation ClearPEM detector model

  12. LYSO/BaSO4 Matrix Detector Modules LYSO:Ce Crystals 2 x 2 x 20 mm3

  13. Simulação completa do sistema ClearPEM Simulation Framework • Simulações Monte Carlo com GEANT4. • Fantoma NCAT. • “Uptake” standard de uma injecção de 370 MBq. • Concentração de 2.1 kBq/cc nos tecidos moles. • Geometria detalhada do detector. • Inclui simulação do trigger e sistema de aquisição de dados.

  14. Actividade do fundo : actividade da lesão Actividade do fundo : actividade da lesão Actividade do fundo : actividade da lesão Actividade do fundo : actividade da lesão 1:13 1:13 1:13 1:13 1:10 1:10 1:10 1:10 1:5 1:5 1:5 1:5 1:4 1:4 1:4 1:4 Boa visibilidade Fraca visibilidade Não visivel Imagens Reconstruidas da lesão 7 mm Ø lesion 10 mm Ø lesion 3 mm Ø lesion 5 mm Ø lesion (5 min aquisição total)

  15. Data Acquisition Requirements • Coincidence digital trigger: • Digital algorithms (time and energy) • Time resolution ~ 1 ns • Good efficiency for multi-hit (Compton) events • Fast Data Acquisition: • Data acquisition system able to cope with a single photon background rate of the order of 10 MHz • The data acquisition efficiency larger than 90%. • Pipeline structures for minimum dead time

  16. On-Detector Off-Detector Frontend Boards DAE crate Digital trigger Data reduction Data readout 600 MHz PC Ampli AnalogMux 192:2 ADC 100 MHz 10 bit Serializer Service Boards Arquitectura do sistema de electrónica Frontend Boards Data Acquisition Electronics • Amplifier/ Multiplexer ASIC: • Sampling ADC (100 MHz) • Links LVDS • Crate 6U • 4 DAQ boards • 1 Trigger/DCC board • FPGAs 4 M gates Service Boards • APD Bias Voltage regulation • T, P monitoring • Power distribution

  17. Frontend ASIC Frontend ASIC Specifications: Technology AMS 0.35 m CMOS Input: 192 channels Noise: ENC ~ 1000 e- Power per chip : < 2 mW/channel Clock frequency : 100 MHz Shaping: Peaking time 40 ns Analog memories: 10 samples Output multiplexing: 2 highest channels ASIC V1 Layout • ASIC V1: • sampled-data memory, multiplexers, control logic OK • input amplifier with unstable bias levels

  18. Layout of Test ASIC V2 8 channels + switches + control logic + self-test multiplexers + buffers Area – 9.44 mm2 1600 m 5900 m Control Logic 4 channels 4channels

  19. DAQ CONN C D FE Serv LV A A D C F A A V O O E H S C C D S A A v L I I O O r e V S S S S V A A A A e r I I L v O O A A D S C C S H E O O V F A A C D A A FE Serv LV D C DAQ CONN Integração da Electrónica de Frontend • Compact system inside the PEM Detector Head: • 6000 APD channels • 400 HV lines • 160 high speed (600 MHz) output lines • High frequency clock (100 MHz) Frontend Board Detector Supermodule

  20. Data Acquisition System DAQ module: - pipeline data storage - hit energy and time calculation Trigger module: - performs coincidence trigger - random triggers - singles trigger Filter Module: - rejects out-of-time data - rejects high multiplicity events DCC module: - collects relevant data - data transfer to PC

  21. Control PCI Interface Processing Trigger and Data Acquisition Boards DAQ Board DAQ Board tested successfully Processing Deserializers TRG/DCC Board is under test TRG/DCC Board Control

  22. Detector Heads Detector heads Patch Panel Water distribution block Adapter for source mounting Collision detection switches Cable carrier Electromechanical safety switch

  23. Robot

  24. Protótipo na fase de montagem Robot

  25. Robot

  26. O PEM na imprensa: Correio da Manhã

  27. O PEM na imprensa: Expresso

  28. O PEM na televisão

  29. O Detector ISPA

  30. Low spatial resolution (typically 3 to 8 mm) Planar Imaging SPECT PET Nuclear Medicine Anger gamma camera Background motivation ISPA group at CERN (Imaging Silicon Pixel Array) High-energy semiconductor particle tracking detectors Low-energy imaging applications Technology transfer Compact, handheldandhigh resolution gamma camera system

  31. Operation principle Photocathode Silicon pixel detector Collimator Electrostatic shield -20 kV 0 V Electrostatic tube Crystal scintillator Not to Scale

  32. Operation principle -20 kV 0 V Not to Scale

  33. -20 kV 0 V Operation principle

  34. Operation principle Analog information Valid 2D hit maps -20 kV 0 V Digital information

  35. Operation principle Analog information 8 mm x 6.4 mm -20 kV 0 V 3 holes of 1 mm separated by 2 mm Digital information

  36. Technical implementations and results ISPA-tube COLLIMATOR Type Parallel-hole (rippled foils) Material Tungsten W Area 9 mm x 10 mm Length 26 mm Septa 0.06 mm Equivalent hole diameter 0.6 mm GEANT 3 simulations (122 keV point source @ 1 cm)

  37. ISPA-tube COLLIMATOR Results Good collimator for high resolution applications where the low sensitivity can be compensated by increasing the acquisition time or the radioisotope activity concentration

  38. Technical implementations and results ISPA-tube CRYSTAL SCINTILLATOR Material YAP:Ce (Yttrium-Aluminiun Perovskite doped with Cerium) Size 31 mm diameter Thickness 2 mm Light yield 10 ph/keV Decay time 27 ns Wavelength of maximumemission 370 nm Absorption efficiency 89% @ 60 keV Al 95% reflectivity

  39. Final evaluation 60 keV point source Setup A (without collimator) Setup B (with collimator)

  40. Final evaluation Images of a 60 keV -source through a 2-holes (0.35 mm ) lead collimator 8 mm 8 mm 6.4 mm Setup A (without collimator) Setup B (with collimator) Results The intrinsic resolution of the ISPA-tube has been estimated to be ~0.2 mm The extrinsic (with the tungsten collimator) has been estimated to be ~0.7 mm The energy resolution of the ISPA-tube has been estimated to be 23% FWHM at 60keV

  41. Final evaluation SPECT camera 140 keV point source ISPA-tube 122 keV point source

  42. Final evaluation After a normalization of both test condition setups (time-activity concentration and energy sensitivity) SPECT camera ISPA-tube 5 minutes equivalent 14000 counts FWHM ~4.3 mm 2800 counts FWHM ~0.6 mm

  43. The timing RPC detector techonology -HV Particle E Resistive material, glass Sensitive Area Conductive material, Aluminum • Main features • Timing resolution ~ 50 ps σ. • Efficiency 75% for a 300 μm gap • No energy resolution. • Possibility to measure the position. Precise gas gap with few 100 mm MIPS Gas gap

  44. S tacked RPCs e- e+ - e .......... - e - e The basic idea for RPC-based TOF-PET The converter-plate principle Use the electrode plates as a g converter, taking advantage of the natural layered construction of the RPCs. [Blanco 2002] Time resolution for 511 keV photons: (our routine lab-test tool) 90 ps s for 1 photon 300 psFWHM for the photon pair Very small gas gap to minimize intrinsic internal error A previous work on PET with gaseous detectors(21 lead plates + 20 MWPCs = 7% efficiency) “The Rutherford Appleton Laboratory´s Mark I Multiwire Proportional Counter Positron Camera” J.E. Bateman et al. NIM 225 (1984) 209-231

  45. Comparison with the standard PET technology Disadvantages Certainly a much smaller efficiency: 20 to 50% as compared to 70 to 80%. No energy resolution, but there is an equivalent energy sensitivity... more later. Advantages Increasing system sensitivity Inexpensive  large areas possible  large solid angle coverage Excelent timing  TOF-PET possible+optimum randoms rejection Increasing position accuracy Gaseous detectors routinely deliver 0.1 mm resolution Full 3D localization possible  no gross parallax error The very small gap minimizes intrinsic errors Other Compatible with the magnetic field  PET-MRI possible Possible specialized PETapplications Whole-bodyHuman PET 1 mm Small Animal PET Simulation: 0.51mm FWHM

  46. Small animal PET - a first prototype Charge-sensitive electronics allowing interstrip position interpolation Aimed at verifying the concept and show the viability of a sub-millimetric spatial resolution. 32 strips 16 plates ....... ....... 16 stacked RPCs Depth of interaction Z 2D measurement of the photon interaction point X Transaxial

  47. System

  48. SIEMENS Full-body human PET Standard PET Whole-body FOV PET [D.B.Crosetto 2000 IEEE NSS] 2 m 15 cm Made with crystal “blocks” 5x5 cm Extremely expensive if based on crystals  RPC-PET Comercial value=1.5M€

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