FPGA-Based Interface of Digital DAQ System for Double-Scattering Compton Camera

다국어 초록 (Multilingual Abstract)

Purpose The double-scattering Compton camera (DSCC) is a radiation imaging system that can provide both unknown sourceenergy spectra and 3D spatial source distributions. The energies and detection locations measured in coincidence with threeCdZnTe (CZT) detectors contribute to reconstructing emission energies and a spatial image based on conical surface integrals. Inthis study, we developed a digital data acquisition (DAQ) board to support our research into coincidence detection in the DSCC.
Methods The main components of the digital DAQ board were 12 ADCs and one field programmable gate array (FPGA). TheADCs digitized the analog 96-channel CZTsignals at a sampling rate of 50MHz and transferred the serialized ADC samples andthe bit and frame clocks to the FPGA. In order to correctly capture the ADC sample bits in the FPGA, we conducted individualsync calibrations for all the ADC channels to align the bit and frame clocks to the right positions of the ADC sample bits. TheFPGA logic design was composed of IDELAYand IDDR components, six shift registers, and bit slip buffer resources.
Results Using a Deskew test pattern, the delay value of the IDELAY component was determined to align the bit clock to thecenter of each sample bit.We determined the bit slip in the 12-bit ADC sample using an MSB test pattern by checking where theMSB value of one is located in the captured parallel data.
Conclusions After sync calibration, we tested the interface between the ADCs and the FPGA with a synthetic analog Gaussiansignal. The 96 ADC channels yielded a mean R2 goodness-of-fit value of 0.95 between the Gaussian curve and the captured 12-bit parallel data.

참고문헌 (Reference)

1 Wulf E, "Thick silicon strip detector Compton imager" 51 : 1997-2003, 2004

2 유익동, "The Current Status of SPECT or SPECT/CT in South Korea" 대한핵의학회 51 (51): 101-105, 2017

3 Kim S, "Resolution recovery reconstruction for a Compton camera" 58 : 2823-2840, 2013

4 Smith B, "Reconstruction methods and completeness conditions for two Compton data models" 22 : 445-459, 2005

5 Sato Y, "Radiation imaging system using a Compton gamma-ray imager mounted on a remotely operated machine" 50 : 1062-1066, 2017

6 Kamea T, "Prototype design of multiple Compton gamma-ray camera" 35 : 352-355, 1988

7 Peterson S, "Optimizing a three-stage Compton camera for measuring prompt gamma rays emitted during proton radiotherapy" 55 : 6841-6856, 2010

8 Seo H, "Multitracing capability of double-scattering Compton imager with NaI(Tl) scintillator absorber" 57 : 1420-1425, 2010

9 Motomura S, "Multiple molecular simultaneous imaging in a live mouse using semiconductor Compton camera" 23 : 1089-1092, 2008

10 Dogan N, "Multiple Compton scattering gamma ray imaging camera" 299 : 501-506, 1990

11 Gambhir S, "Molecular imaging of cancer with positron emission tomography" 2 : 683-693, 2002

12 Vetter K, "High-sensitivity Compton imaging with position-sensitive Si and Ge detectors" 579 : 363-366, 2007

13 Phillips G, "Gamma-ray imaging with Compton cameras" 99 : 674-677, 1995

14 Motomura S, "Gamma-ray Compton imaging of multitracer in biological samples using strip germanium telescope" 54 : 710-717, 2007

15 Kim S, "Fully threedimensional OSEM-based image reconstruction for Compton imaging using optimized ordering schemes" 55 : 5007-5027, 2010

16 권현우, "FDG Whole-Body PET/MRI in Oncology: a Systematic Review" 대한핵의학회 51 (51): 22-31, 2017

17 Du Y, "Evaluation of a Compton scattering camera using 3-D position sensitive CdZnTe detectors" 457 : 203-211, 2001

18 Saurav ZK Sajib, "Electrodeless Conductivity Tensor Imaging (CTI) using MRI: Basic Theory and Animal Experiments" 대한의용생체공학회 8 (8): 273-282, 2018

19 고근배, "Development of FPGA-based Coincidence Units with Veto Function" 대한의용생체공학회 1 (1): 27-31, 2011

20 Watanabe S, "Development of CdTe pixel detectors for Compton cameras" 567 : 150-153, 2006

21 Richard M-H, "Design guidelines for a double scattering Compton camera for prompt-γ imaging during ion beam therapy:a Monte Carlo simulation study" 58 : 87-94, 2011

22 박성조, "Contrast-enhanced dual mode imaging: photoacoustic imaging plus more" 대한의용생체공학회 7 (7): 121-133, 2017

23 "Artix-7 FPGA Family" Xilinx.com

24 Singh M, "An electronically collimated gamma camera for single photon emission computed tomography: part1 and 2" 10 : 421-427, 1983

25 "ADS5281 Analog-to-Digital Converter" TI.com

26 Jiang J, "A prototype of aerial radiation monitoring system using an unmanned helicopter mounting a GAGG scintillator Compton camera" 53 (53): 1067-1075, 2016

27 Todd R, "A proposed gamma camera" 251 : 132-134, 1974

28 Kamea T, "A new method to measure energy, direction, and polarization of gamma-rays" 260 : 254-257, 1987

29 Yang Y, "A Compton camera for multitracer imaging" 48 : 656-661, 2001