The long patient port of a PET scanner tends to put stress on patients, especially patients with claustrophobia. It also prevents doctors and technicians from taking care during scanning. In this paper, we proposed an 'open PET' geometry, which consists two axially separated detector rings. A continuous field-of-view (FOV) including 360° opened gap between rings can be imaged enabling fully 3D image reconstruction all the possible lines-of-response. open will become practical if iterative...

Abstract Positronium (Ps), a hydrogen-like atom consisting of positron and an electron, is efficiently formed in the human body during emission tomography (PET) examination, its decay rate into gamma-ray photons significantly influenced by chemical environment, especially dissolved oxygen concentration (pO 2 ) due to unpaired electrons. However, functionality PET has been underestimated neglecting specific information provided Ps. By comparing rates O -, N air-saturated waters, here we show...

We have developed a fast x-ray detector using an organic-inorganic perovskite scintillator of phenethylamine lead bromide (PhE-PbBr4). The had dominant light emission with decay time 9.9 ns. An equipped 0.9-mm-thick PhE-PbBr4 crystal was used to detect nuclear resonant scattering in N61i (the first excited level: 67.41 keV; lifetime: 7.6 ns) by synchrotron radiation. With this detector, we could successfully record the decaying gamma rays emitted from resolution 0.7 ns (full width at half...

The concept of a "quantum scintillator", satisfying both large light output and quick response, is proposed. temporal behavior scintillation from (n-C6H13NH3)2PbI4, natural multiple quantum well structure provided by the lead-halide-based perovskite-type organic-inorganic hybrid compound, was investigated using short-pulsed electron beam streak camera. A decay component 390 ps efficiently observed even at room temperature. This response notably quicker than conventional Ce3+-activated...

Abstract The effects of organic moieties on the scintillation properties organic–inorganic layered perovskite-type compounds have been investigated. Three kinds single crystals were fabricated, namely, (C 4 H 9 NH 3 ) 2 PbBr (C4), 6 5 CH (Ben), and C (Phe). Among crystals, light output Phe was found to greatest value when exposed X-ray radiation (67.4 keV). 0.62 times that YAP:Ce. relative values outputs among fabricated under correlated well with those quantum efficiencies luminescence...

Crystals of the title compound, {(C(6)H(5)C(2)H(4)NH(3))(2)[PbBr(4)]}(n), were grown at room temperature from a solution in N,N-dimethyl-formamide (DMF) using nitro-methane as poor solvent. This perovskite-type organic-inorganic hybrid compound consists well ordered sheets corner-sharing disordered PbBr(6) octa-hedra separated by bilayers phenethyl-ammonium cations. The are rotated and tilted due to N-H⋯Br hydrogen bonds with ammonium groups, generating superstructure unit cell similar that...

A method for creating a fast scintillator is proposed. Recently, much attention has been paid to pure semiconductors during development of subnanosecond solid scintillators. However, the bulky samples rarely exhibit high light yields at room temperature because thermal instability excitonic levels. The authors employed optimum three- and two-dimensional semiconducting systems provided by lead-halide-based compounds demonstrate advantage low dimensionality in scintillating efficiency. Their...

The x-ray detection capability of a scintillation detector equipped with BaCl2 single crystal was evaluated. decay kinetics can be expressed by sum two exponential components. fast and slow components have lifetimes 1.5 85 ns, respectively. total light output is 5% that YAP:Ce. A subnanosecond timing resolution obtained. efficiency 67.41 keV 87% for 6-mm thick. Thus, excellent high simultaneously achieved. Additionally, luminescence characteristics under vacuum ultraviolet excitation been...

We have developed a new three-dimensional (3D) position sensitive radiation detector, called the X'tal cube. The cube is composed of scintillation crystal block and number multi-pixel photon counters (MPPCs) which are coupled on all six sides block. segmented into cubes no reflector used between segments. Scintillation light originating in segment accordingly propagates three-dimensionally along alignment segments efficiently detected by MPPCs. could be as detector element PET system, for...

Positronium (Ps) lifetime imaging is gaining attention to bring out additional biomedical information from positron emission tomography (PET). The of Psin vivocan change depending on the physical and chemical environments related some diseases. Due limited sensitivity, Ps may require merging voxels for statistical accuracy. This paper presents a method separating components in voxel avoid loss due averaging. mathematics this separation inverse Laplace transform (ILT), authors examined an...

An 8-layer depth of interaction (DOI) detector was designed based on the technique we have developed for 4-layer DOI detectors. The new achieves encoding by pulse shape discrimination (2-layer encoding) and an optimized reflector arrangement in a 3-dimensional crystal array (4-layer encoding). Its capability proved with 10times10 Gd <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> SiO xmlns:xlink="http://www.w3.org/1999/xlink">5</sub>...

Annihilation photon acollinearity is a fundamental but little investigated problem in positron emission tomography (PET). In this paper, the cause of angular deviation from 180.00° described as well how to evaluate it under conditions spatially distributed radiation source and limited acquisition time for human body. A relationship between shape photopeak spectrum distribution formulated using conservation laws momentum energy over pair annihilation. Then formula used pool phantom body with...

We have proposed an ldquoOpenPETrdquo geometry, which consists of two axially separated detector rings, each axial length W. A long and continuous field-of-view (FOV) including a 360-degree open gap G between rings can be imaged through iterative image reconstruction. In addition to providing stress-less PET scanning simultaneous PET/CT, the OpenPET is expected lead realization in-beam PET. The also extends FOV with limited number detectors. However, 3 W because maximum limit obtain this...

Scintillation characteristics of undoped BaCl2, a novel fast scintillation material, were investigated. photons with wavelength ranging from 250–600 nm observed two luminescence bands at 300 and 400 nm. The time profiles consisted lifetime components. shorter component had 1.6 ns, while the longer one several tens nanoseconds. origin has been attributed to self-trapped excitons, whereas slow is considered be an extrinsic luminescence. photoelectron yield BaCl2 coupled bialkali photocathode...

We have proposed an 'OpenPET' geometry which consists of two detector rings axial length W each axially separated by a gap G. In order to obtain continuous field-of-view (FOV) 2W+G, the maximum limit for G must be W. However, valleys sensitivity appear, one on side gap. practice, should G<W in compensate valleys. this paper, we alternative method improve uniformity while maintaining The consisted four units obtained dividing right and left unit into units. inner formed main gap, outer were...

We report a method to determine time evolution of ortho-positronium ($o$-Ps) kinetic energy with higher accuracy and sensitivity than conventional methods. Our utilizes the fact that, during Ps-Xe collisions, an $o$-Ps atom can undergo spin-conversion reaction induced by spin-orbit interaction decay into two gamma-ray photons that rate strongly depends on because occurs only in $p$-wave scattering; thus small change leads large two-photon annihilation rate. Utilizing this as ``lens'' magnify...

The human granulocyte macrophage colony-stimulating factor (GM-CSF) receptor alpha-chain, a low affinity component of the receptor, was solubilized and affinity-purified from placenta using biotinylated GM-CSF. Scatchard analysis 125I-GM-CSF binding to placental membrane extract disclosed that GM-CSF had dissociation constant (Kd) 0.5-0.8 nM, corresponding Kd value alpha-chain on intact membrane. Affinity labeling protein photoreactive cross-linking agent,...

The jPET-D4 is the first PET scanner to introduce a unique four-layer depth-of-interaction (DOI) detector scheme in order achieve high sensitivity and uniform spatial resolution. This paper compares measurement Monte Carlo simulation results of static physics performance this prototype research scanner. Measurement include single coincidence energy spectra, point line source sensitivities, axial profile (slice profile) scatter fraction. We use GATE (Geant4 application for tomographic...