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Peng Q, Holland SE, Choong WS, Budinger TF, Moses WW. Real-time quantitative ex vivo direct autoradiography with 10 μm pixel resolution. Annu Int Conf IEEE Eng Med Biol Soc 2011; 2011:6273-6276. [PMID: 22255772 DOI: 10.1109/iembs.2011.6091548] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We present three new autoradiography methods to map positron emission rate of a bio-specimen slice with high resolution. One is based on LBNL scientific charge coupled device (CCD) and the other two are based on conventional CCDs. High conversion efficiency (100k e-h pairs / 0.5 MeV positron) and low dark current (1.75 × 10(-4) e-/pix/sec) can be achieved using the LBNL CCD. The theoretical calculations and preliminary experiments show that an 86 μm spatial resolution can be achieved when imaging a 100 μm thick tissue soaked with (18)F which produce higher energy positron. The main disadvantage of the LBNL CCD we tested is that a very low operating temperature is required to eliminate dark current. This dramatically increases the system cost. In addition, the integration time of the CCD needs to be short enough to avoid overlapping of the positron trajectories. Conventional CCDs have lower conversion efficiency (2k e-h pairs / 0.5 MeV positron) and higher dark current (200 e-/pix/sec), but are more cost-efficient and the requirement for the readout frequency is much lower. The conversion efficiency of the conventional CCD imager can be improved by 17 times by inserting a 100 μm layer of phosphor between the sample and the imager. However, the light emitted from the phosphor screen will be ~100 μm diameter, which severely degrades the spatial resolution. A high readout frequency is also required to avoid the overlapping. The CCD systems designed in this study will be used to map positron emission rate of bio-specimens such as cancerous tissues acquired in regular biopsy procedure. They can also be used to corroborate tracer kinetic modeling at a cellular level.
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Affiliation(s)
- Q Peng
- Lawrence Berkeley National Laboratory, Berkeley, CA 94720,
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Kim H, Frisch H, Chen CT, Genat JF, Tang F, Moses WW, Choong WS, Kao CM. A Design of a PET Detector Using Micro-Channel Plate Photomultipliers with Transmission-Line Readout. Nucl Instrum Methods Phys Res A 2010; 622:628-636. [PMID: 21048886 PMCID: PMC2967035 DOI: 10.1016/j.nima.2010.07.083] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A computer simulation study has been conducted to investigate the feasibility of a positron emission tomography (PET) detector design by using micro-channel plate (MCP) photomultiplier tubes (PMT) with transmission-line (TL) read-out and waveform sampling. The detector unit consisted of a 24×24 array of pixelated LSO crystals, each of which was 4×4×25 mm(3) in size, and two 102×102 mm(2) MCP-PMTs coupled to both sides of the scintillator array. The crystal (and TL) pitch was 4.25 mm and reflective medium was inserted between the crystals. The transport of the optical photons inside the scintillator were simulated by using the Geant4 package. The output pulses of the MCP-PMT/TL unit were formed by applying the measured single photo-electron response of the MCP-PMT/TL unit to each individual photon that interacts with the photo-cathode of the MCP-PMT. The waveforms of the pulses at both ends of the TL strips were measured and analyzed to produce energy and timing information for the detected event. An experimental setup was developed by employing a Photonis Planacon MCP-PMT (XP85022) and a prototype TL board for measuring the single photo-electron response of the MCP-PMT/TL. The simulation was validated by comparing the predicted output pulses to measurements obtained with a single MCP-PMT/TL coupled to an LSO crystal exposed to 511 keV gamma rays. The validated simulation was then used to investigate the performance of the proposed new detector design. Our simulation result indicates an energy resolution of ~11% at 511 keV. When using a 400-600 keV energy window, we obtain a coincidence timing resolution of ~323 ps FWHM and a coincidence detection efficiency of ~40% for normally-incident 511keV photons. For the positioning accuracy, it is determined by the pitch of the TLs (and crystals) in the direction normal to the TLs and measured to be ~2.5 mm in the direction parallel to the TLs. The energy and timing obtained at the front- and back-end of the scintillator array also show differences that are correlated with the depth of interaction of the event.
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Affiliation(s)
- H. Kim
- Department of Radiology, University of Chicago, Chicago, IL 60637
| | - H. Frisch
- Enrico Fermi Institute, University of Chicago, Chicago, IL 60637
| | - C.-T. Chen
- Department of Radiology, University of Chicago, Chicago, IL 60637
| | - J.-F. Genat
- Enrico Fermi Institute, University of Chicago, Chicago, IL 60637
| | - F. Tang
- Enrico Fermi Institute, University of Chicago, Chicago, IL 60637
| | - W. W. Moses
- Lawrence Berkeley National Laboratory, Berkeley,CA 94720
| | - W. S. Choong
- Lawrence Berkeley National Laboratory, Berkeley,CA 94720
| | - C.-M. Kao
- Department of Radiology, University of Chicago, Chicago, IL 60637
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Kim H, Kao CM, Xie Q, Chen CT, Zhou L, Tang F, Frisch H, Moses WW, Choong WS. A Multi-Threshold Sampling Method for TOF PET Signal Processing. Nucl Instrum Methods Phys Res A 2009; 602:618-621. [PMID: 19690623 PMCID: PMC2727689 DOI: 10.1016/j.nima.2009.01.100] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
As an approach to realizing all-digital data acquisition for positron emission tomography (PET), we have previously proposed and studied a multi-threshold sampling method to generate samples of a PET event waveform with respect to a few user-defined amplitudes. In this sampling scheme, one can extract both the energy and timing information for an event. In this paper, we report our prototype implementation of this sampling method and the performance results obtained with this prototype. The prototype consists of two multi-threshold discriminator boards and a time-to-digital converter (TDC) board. Each of the multi-threshold discriminator boards takes one input and provides up to 8 threshold levels, which can be defined by users, for sampling the input signal. The TDC board employs the CERN HPTDC chip that determines the digitized times of the leading and falling edges of the discriminator output pulses. We connect our prototype electronics to the outputs of two Hamamatsu R9800 photomultiplier tubes (PMTs) that are individually coupled to a 6.25×6.25×25mm(3) LSO crystal. By analyzing waveform samples generated by using four thresholds, we obtain a coincidence timing resolution of about 340 ps and an ∼18% energy resolution at 511 keV. We are also able to estimate the decay-time constant from the resulting samples and obtain a mean value of 44ns with an ∼9 ns FWHM. In comparison, using digitized waveforms obtained at a 20 GSps sampling rate for the same LSO/PMT modules we obtain ∼300 ps coincidence timing resolution, ∼14% energy resolution at 511 keV, and ∼5 ns FWHM for the estimated decay-time constant. Details of the results on the timing and energy resolutions by using the multi-threshold method indicate that it is a promising approach for implementing digital PET data acquisition.
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Affiliation(s)
- H. Kim
- Department of Radiology, University of Chicago, Chicago, IL 60637
| | - C. M. Kao
- Department of Radiology, University of Chicago, Chicago, IL 60637
| | - Q. Xie
- Department of Radiology, University of Chicago, Chicago, IL 60637
| | - C. T. Chen
- Department of Radiology, University of Chicago, Chicago, IL 60637
| | - L. Zhou
- Enrico Fermi Institute, University of Chicago, Chicago, IL 60637
| | - F. Tang
- Enrico Fermi Institute, University of Chicago, Chicago, IL 60637
| | - H. Frisch
- Enrico Fermi Institute, University of Chicago, Chicago, IL 60637
| | - W. W. Moses
- Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | - W. S. Choong
- Lawrence Berkeley National Laboratory, Berkeley, CA 94720
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Rajaram D, Burnstein RA, Chakravorty A, Chan A, Chen YC, Choong WS, Clark K, Dukes EC, Durandet C, Felix J, Gidal G, Gu P, Gustafson HR, Ho C, Holmstrom T, Huang M, James C, Jenkins CM, Kaplan DM, Lederman LM, Leros N, Longo MJ, Lopez F, Lu LC, Luebke W, Luk KB, Nelson KS, Park HK, Perroud JP, Rubin HA, Teng PK, Volk J, White CG, White SL, Zyla P. Search for the lepton-number-violating decay Xi(-)-->pmu(-)mu(-). Phys Rev Lett 2005; 94:181801. [PMID: 15904358 DOI: 10.1103/physrevlett.94.181801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2004] [Indexed: 05/02/2023]
Abstract
A sensitive search for the lepton-number-violating decay Xi(-)-->pmu(-)mu(-) has been performed using a sample of approximately 10(9) Xi(-) hyperons produced in 800 GeV/c p-Cu collisions. We obtain B(Xi(-)-->pmu(-)mu(-))<4.0x10(-8) at 90% confidence, improving on the best previous limit by 4 orders of magnitude.
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Affiliation(s)
- D Rajaram
- Illinois Institute of Technology, Chicago, IL 60616, USA
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White CG, Burnstein RA, Chakravorty A, Chan A, Chen YC, Choong WS, Clark K, Dukes EC, Durandet C, Felix J, Gidal G, Gu P, Gustafson HR, Ho C, Holmstrom T, Huang M, James C, Jenkins CM, Kaplan DM, Lederman LM, Leros N, Longo MJ, Lopez F, Lu LC, Luebke W, Luk KB, Nelson KS, Park HK, Perroud JP, Rajaram D, Rubin HA, Teng PK, Volk J, White SL, Zyla P. Search for DeltaS = 2 nonleptonic hyperon decays. Phys Rev Lett 2005; 94:101804. [PMID: 15783474 DOI: 10.1103/physrevlett.94.101804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2004] [Indexed: 05/24/2023]
Abstract
A sensitive search for the rare decays Omega(-)--> Lambdapi(-) and Xi(0)--> ppi(-) has been performed using data from the 1997 run of the HyperCP (Fermilab E871) experiment. Limits on other such processes do not exclude the possibility of observable rates for |DeltaS| = 2 nonleptonic hyperon decays, provided the decays occur through parity-odd operators. We obtain the branching-fraction limits B(Omega(-)-->Lambdapi(-)) < 2.9 x 10(-6) and B(Xi(0)--> ppi(-)) < 8.2 x 10(-6), both at 90% confidence level.
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Affiliation(s)
- C G White
- Illinois Institute of Technology, Chicago, Illinois 60616, USA
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Park HK, Burnstein RA, Chakravorty A, Chen YC, Choong WS, Clark K, Dukes EC, Durandet C, Felix J, Fu Y, Gidal G, Gustafson HR, Holmstrom T, Huang M, James C, Jenkins CM, Jones T, Kaplan DM, Lederman LM, Leros N, Longo MJ, Lopez F, Lu LC, Luebke W, Luk KB, Nelson KS, Perroud JP, Rajaram D, Rubin HA, Volk J, White CG, White SL, Zyla P. Evidence for the decay sigma+ --> pmu+ mu-. Phys Rev Lett 2005; 94:021801. [PMID: 15698162 DOI: 10.1103/physrevlett.94.021801] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2004] [Indexed: 05/24/2023]
Abstract
We report the first evidence for the decay Sigma(+)-->pmu(+)mu(-) from data taken by the HyperCP (E871) experiment at Fermilab. Based on three observed events, the branching ratio is B(Sigma(+)-->pmu(+)mu(-))=[8.6(+6.6)(-5.4)(stat)+/-5.5(syst)]x10(-8). The narrow range of dimuon masses may indicate that the decay proceeds via a neutral intermediate state, Sigma(+)-->pP(0),P0-->mu(+)mu(-) with a P0 mass of 214.3+/-0.5 MeV/c(2) and branching ratio B(Sigma(+)-->pP(0),P0-->mu(+)mu(-))=[3.1(+2.4)(-1.9)(stat)+/-1.5(syst)]x10(-8).
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Affiliation(s)
- H K Park
- University of Michigan, Ann Arbor, Michigan 48109, USA
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Holmstrom T, Leros N, Burnstein RA, Chakravorty A, Chan A, Chen YC, Choong WS, Clark K, Dukes EC, Durandet C, Felix J, Fu Y, Gidal G, Gu P, Gustafson HR, Ho C, Huang M, James C, Jenkins CM, Jones T, Kaplan DM, Lederman LM, Longo MJ, Lopez F, Lu LC, Luebke W, Luk KB, Nelson KS, Park HK, Perroud JP, Rajaram D, Rubin HA, Teng PK, Volk J, White CG, White SL, Zyla P. Search for CP violation in charged-Xi and Lambda hyperon decays. Phys Rev Lett 2004; 93:262001. [PMID: 15697968 DOI: 10.1103/physrevlett.93.262001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2004] [Indexed: 05/24/2023]
Abstract
We have compared the p and p angular distributions in 117 x 10(6) Xi- -->Lambdapi- -->ppi-pi- and 41 x 10(6) Xi+ -->Lambda pi+ -->p pi+pi+ decays using a subset of the data from the HyperCP experiment (E871) at Fermilab. We find no evidence of CP violation, with the direct-CP-violating parameter AXiLambda identical with (alphaXialphaLambda-alpha Xialpha Lambda)/(alphaXialphaLambda+alphaXialphaLambda)=[0.0+/-5.1(stat)+/-4.4(syst)] x 10(-4).
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Affiliation(s)
- T Holmstrom
- University of Virginia, Charlottesville, Virginia 22904, USA
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Park HK, Burnstein RA, Chakravorty A, Chan A, Chen YC, Choong WS, Clark K, Dukes EC, Durandet C, Felix J, Gidal G, Gu P, Gustafson HR, Ho C, Holmstrom T, Huang M, James C, Jenkins CM, Kaplan DM, Lederman LM, Leros N, Longo MJ, Lopez F, Lu L, Luebke W, Luk KB, Nelson KS, Perroud JP, Rajaram D, Rubin HA, Teng PK, Volk J, White C, White S, Zyla P. Observation of the decay K- --> pi(-)mu(+)mu(-) and measurements of the branching ratios for K+/- --> pi(+/-)mu(+)mu(-). Phys Rev Lett 2002; 88:111801. [PMID: 11909394 DOI: 10.1103/physrevlett.88.111801] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2001] [Indexed: 05/23/2023]
Abstract
Using data collected with the HyperCP (E871) spectrometer during the 1997 fixed-target run at Fermilab, we report the first observation of the decay K--->pi(-)mu(+)mu(-) and new measurements of the branching ratios for K+/--->pi(+/-)mu(+)mu(-). By combining the branching ratios for the decays K+-->pi(+)mu(+)mu(-) and K--->pi(-)mu(+)mu(-), we measure Gamma(K+/--->pi(+/-)mu(+)mu(-))/Gamma(K+/--->all) = (9.8+/-1.0+/-0.5)x10(-8). The CP asymmetry between the rates of the two decay modes is [Gamma(K+-->pi(+)mu(+)mu(-))-Gamma(K--->pi(-)mu(+)mu(-))]/[Gamma(K+-->pi(+)mu(+)mu(-))+Gamma(K--->pi(-)mu(+)mu(-))] = -0.02+/-0.11+/-0.04.
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Affiliation(s)
- H K Park
- University of Michigan, Ann Arbor, Michigan 48109, USA
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Choong WS, Silverman D. New phases in CP-violating B decay asymmetries from mixing to singlet down quarks. Phys Rev D Part Fields 1994; 49:2322-2330. [PMID: 10017221 DOI: 10.1103/physrevd.49.2322] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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