Time-of-flight positron imaging and the resolution improvement by an iterative method

Yamamoto, Mikio; Nohara, Norimasa; Tanaka, Eiichi; Tomitani, Takehiro; Murayama, Hideo; Sato, N.; Omura, T.; Tsuchiya, Yutaka

doi:10.1109/23.34592

Cited by 12 publications

(7 citation statements)

References 8 publications

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“…At that time, the three main groups involved in the development of ToF scanners were at CEA-LETI in France [26,27], University of Washington St. Louis in Missouri, USA [28,29], and the University of Texas, USA [30]. Other groups involved in ToF-PET research were the National Institute of Radiological Science in Chiba, Japan [31,32], and Washington University in Seattle, WA, USA [33]. Cesium fluoride (CsF) and barium fluoride (BaF 2 ) detectors were used in the first-generation TOF-PET [34][35][36].…”

Section: History and Early Research Of Tof-petmentioning

confidence: 99%

Instrumentation for Time-of-Flight Positron Emission Tomography

Ullah

Pratiwi

Cheon

et al. 2016

Nucl Med Mol Imaging

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Positron emission tomography (PET) is a molecular imaging modality that provides information at the molecular level. This system is composed of radiation detectors to detect incoming coincident annihilation gamma photons emitted from the radiopharmaceutical injected into a patient's body and uses these data to reconstruct images. A major trend in PET instrumentation is the development of time-of-flight positron emission tomography (ToF-PET). In ToF-PET, the time information (the instant the radiation is detected) is incorporated for image reconstruction. Therefore, precise and accurate timing recording is crucial in ToF-PET. ToF-PET leads to better localization of the annihilation event and thus results in overall improvement in the signal-to-noise ratio (SNR) of the reconstructed image. Several factors affect the timing performance of ToF-PET. In this article, the background, early research and recent advances in ToF-PET instrumentation are presented. Emphasis is placed on the various types of scintillators, photodetectors and electronic circuitry for use in ToF-PET, and their impact on timing resolution is discussed.

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Section: History and Early Research Of Tof-petmentioning

confidence: 99%

Instrumentation for Time-of-Flight Positron Emission Tomography

Ullah

Pratiwi

Cheon

et al. 2016

Nucl Med Mol Imaging

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“…Reconstruction algorithms for TOF PET were developed in the 1980s and are an adaptation of the filtered backprojection algorithm [13], [16]- [20]. The main difference is that the fundamental datum consists of both the locations of the two detector elements that observe 511 keV photons and the difference in Fig.…”

Section: A Theoretical Basismentioning

confidence: 99%

Time of flight in PET revisited

Moses

2003

IEEE Trans. Nucl. Sci.

310

186

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PET scanners based on LSO have the potential for significantly better coincidence timing resolution than the 6 ns FWHM typically achieved with BGO. This study analyzes the performance enhancements made possible by improved timing as a function of the coincidence time resolution. If 500 ps FWHM coincidence timing resolution can be achieved in a complete PET camera, the following four benefits can be realized for whole-body FDG imaging: 1) the random event rate can be reduced by using a narrower coincidence timing window, increasing the peak NECR by 50%; 2) using time-of-flight (TOF) in the reconstruction algorithm will reduce the noise variance by a factor of 5; 3) emission and transmission data can be acquired simultaneously, reducing the total scan time; and 4) axial blurring can be reduced by using TOF to determine the correct axial plane of origin for each event. While TOF was extensively studied in the 1980s, practical factors limited its effectiveness at that time and little attention has been paid to timing in PET since then. As these potential improvements are substantial and the advent of LSO PET cameras gives us the means to obtain them without other sacrifices, efforts to improve PET timing should resume after their long dormancy.

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“…Time-of-flight (TOF) positron emission tomography (PET) was studied and preliminarily developed in the 1980s (Allemand et al 1980, Budinger 1983, Laval et al 1983, Lewellen et al 1988, Mazoyer et al 1990, Mullani et al 1980, Snyder and Politte 1983, Tomitani 1981, Yamamoto et al 1989, particularly using CsF or BaF 2 . However, the lack of a scintillator able to deliver both proper time resolution and stopping power has prevented TOF from becoming widespread and commercially available.…”

Section: Introductionmentioning

confidence: 99%

First experimental results of time-of-flight reconstruction on an LSO PET scanner

et al. 2005

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Time-of-flight (TOF) positron emission tomography (PET) was studied and preliminarily developed in the 1980s, but the lack of a scintillator able to deliver at the same time proper time resolution and stopping power has prevented this technique from becoming widespread and commercially available. With the introduction of LSO in PET, TOF is now a feasible option. TOF reconstruction has been implemented in the CPS Hi-Rez PET scanner, both with 2D filtered-back-projection (FBP2D) and 3D ordered subset expectation maximization (OSEM3D). A new procedure has been introduced in the time alignment to compensate for the limited digital time resolution of the present electronics. A preliminary version of scatter correction for TOF has been devised and is presented. The measured time resolution of 1.2 ns (FWHM) allowed for a signal-to-noise ratio increase of about 50% in phantoms of about 40 cm transaxial size, or a gain larger than 2 in noise equivalent counts (NEC). TOF reconstruction has shown the expected improvement in SNR, both in simulation and experimental data. First experimental results show two improvements of TOF reconstruction over conventional (non-TOF) reconstruction: a lower noise level and a better capability to resolve structures deep inside large objects.

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Time-of-flight positron imaging and the resolution improvement by an iterative method

Cited by 12 publications

References 8 publications

Instrumentation for Time-of-Flight Positron Emission Tomography

Instrumentation for Time-of-Flight Positron Emission Tomography

Time of flight in PET revisited

First experimental results of time-of-flight reconstruction on an LSO PET scanner

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