Simulation study of a brain PET scanner using TOF-DOI detectors equipped with first interaction position detection.

. The aim of this study is to evaluate the performance characteristics of a brain positron emission tomography (PET) scanner composed of four-layer independent read-out time-of-flight depth-of-interaction (TOF-DOI) detectors capable of first interaction position (FIP) detection, using Geant4 application for tomographic emission(GATE). This includes the spatial resolution, sensitivity, count rate capability, and reconstructed image quality.

Simulation study of potential time-of-flight capabilities for a multilayer DOI-PET detector with an independent readout structure.

A multilayer depth-of-interaction positron emission tomography (DOI-PET) detector with an independent readout structure has a potential advantage as a time-of-flight (TOF)-PET detector. The thin scintillator block of each detector layer can afford an improved coincidence time resolution (CTR) of ∼100 ps because the photon transfer time spread within the scintillator inherently decreases. To evaluate the potential TOF capabilities of a multilayer DOI-PET detector, which consists of thin layers of a cerium-doped lutetium-yttrium oxyorthosilicate (LYSO:Ce) scintillator coupled to a multi-pixel photon counter (MPPC) array, we examined the detector's CTR performance via Monte Carlo simulations.

Performance evaluation of a high-resolution brain PET scanner using four-layer MPPC DOI detectors.

A high-resolution positron emission tomography (PET) scanner, dedicated to brain studies, was developed and its performance was evaluated. A four-layer depth of interaction detector was designed containing five detector units axially lined up per layer board. Each of the detector units consists of a finely segmented (1.

Novel crystal timing calibration method based on total variation.

A novel crystal timing calibration method based on total variation (TV), abbreviated as 'TV merge', has been developed for a high-resolution positron emission tomography (PET) system. The proposed method was developed for a system with a large number of crystals, it can provide timing calibration at the crystal level. In the proposed method, the timing calibration process was formulated as a linear problem.

An animal PET scanner using flat-panel position-sensitive PMTs.

Objective: To design, build, and evaluate an animal PET scanner, which can be used with non-human primates under conscious condition, incorporating flat-panel position-sensitive photomultiplier tubes (PS-PMTs).

Methods: The system contains 30 detector modules, each having two PS-PMTs and 16×18 lutetium–yttrium oxyortho-silicate scintillation crystal arrays. The system has 17,280 crystals (480 per ring) arranged in 36 rings, with a diameter of 508 mm and axial extent of 108 mm.

Alterations in α4β2 nicotinic receptors in cognitive decline in Alzheimer's aetiopathology.

Nicotinic acetylcholine receptor subtype α4β2 is considered important in the regulation of attention and memory, and cholinergic degeneration is known as one pathophysiology of Alzheimer's disease. Brain amyloid-β protein deposition is also a key pathological marker of Alzheimer's disease. Recent amyloid-β imaging has shown many cognitively normal subjects with amyloid-β deposits, indicating a missing link between amyloid-β deposition and cognitive decline.

Potential for reducing the numbers of SiPM readout surfaces of laser-processed X'tal cube PET detectors.

We are developing a three-dimensional (3D) position-sensitive detector with isotropic spatial resolution, the X'tal cube. Originally, our design consisted of a crystal block for which all six surfaces were covered with arrays of multi-pixel photon counters (MPPCs). In this paper, we examined the feasibility of reducing the number of surfaces on which a MPPC array must be connected with the aim of reducing the complexity of the system.

Intrinsic spatial resolution evaluation of the X'tal cube PET detector based on a 3D crystal block segmented by laser processing.

The X'tal cube is a depth-of-interaction (DOI)-PET detector which is aimed at obtaining isotropic resolution by effective readout of scintillation photons from the six sides of a crystal block. The X'tal cube is composed of the 3D crystal block with isotropic resolution and arrays of multi-pixel photon counters (MPPCs). In this study, to fabricate the 3D crystal block efficiently and precisely, we applied a sub-surface laser engraving (SSLE) technique to a monolithic crystal block instead of gluing segmented small crystals.

A SiPM-based isotropic-3D PET detector X'tal cube with a three-dimensional array of 1 mm(3) crystals.

We are developing a novel, general purpose isotropic-3D PET detector X'tal cube which has high spatial resolution in all three dimensions. The research challenge for this detector is implementing effective detection of scintillation photons by covering six faces of a segmented crystal block with silicon photomultipliers (SiPMs). In this paper, we developed the second prototype of the X'tal cube for a proof-of-concept.

[Evaluation of a new, microfluidic chip-based immunoassay for measurement of AFP-L3].

Purpose: AFP-L3 is an isoform of a-fetoprotein which has a fucosylated carbohydrate chain, and the fraction of AFP-L3/total AFP (AFP-L3%) specifically increases in hepatocellular carcinoma (HCC) patients and is widely used for screening and prognosis of HCC. The newly developed microTAS method which combines microchip electrophoresis and lectin affinity electrophoresis can rapidly provide AFP-L3% and total AFP measurements simultaneously at higher sensitivity. Here, we evaluated the system to know its analytical performance and clinical utility.

Coexistence of cranial and spinal subdural hematomas: case report.

A 47-year-old man presented with chronic cranial subdural hematomas (SDHs) associated with spinal SDH manifesting as onset of severe lumbago revealed in the follow up for bilateral subdural effusions after trauma. Left chronic cranial SDH was first identified. Two months after evacuation of the left chronic cranial SDH, he complained of severe lumbago.

[Case of an idiopathic dissecting aneurysm of the superficial temporal artery: a case report].

Aneurysms of the superficial temporal artery are usually traumatic in origin an are pseudoaneurysms. We present a rare case of an idiopathic dissecting aneurysm of the superficial temporal artery in a 40-year-old man without history of trauma. The patient had a pulsatile mass in the left temporal region.

A case of brain metastasis from pulmonary giant cell carcinoma.

A 74-year old female was admitted to our hospital due to sudden right hemiparesis. Precontrast brain computed tomography (CT) revealed multiple high-density masses consistent with multiple hemorrhage, and chest CT scan demonstrated a mass in the left lung field without hemorrhage. Follow-up CT showed enlargement of the multiple intracerebral hemorrhages.

[Fully automated immunoassay system utilizing microchip electrophoresis].

Application of microTAS (micro Total Analysis Systems) technologies utilizing chips with microfluidic channels to clinical diagnostic testing has drawn a lot of attention since it is expected to contribute to shortening reaction time, reduction of reagent/sample consumption, reducing instrument size, and other advantages of microchip electrophoresis. We have developed a fully automated immunoassay system by employing isotachophoresis followed by capillary gel electrophoresis for immunoreaction and B/F separation in microfluidic channels on polymer microchips. Laser-Induced Fluorescence (LIF) was used for detection of the sandwich immunocomplex composed of DNA-conjugate antibody, antigen and fluorescent dye-conjugated antibody.

The generation of lucigenin chemiluminescence from the reaction of guanidino compounds with phenylglyoxal under alkaline conditions and its application.

It is shown that o-carboxyphenylglyoxal, which is converted from ninhydrin by alkali, produces a chemiluminescent lucigenin reaction under alkaline conditions when with reacted with guanidino compounds. It is also demonstrated that phenylglyoxal, which is a model compound of o-carboxyphenylglyoxal, produces a strong chemiluminescent lucigenin reaction under alkaline conditions when reacted with guanidino compounds. Moreover, ESR spectra showed the presence of 5,5-dimethyl-1-pyrroline N-oxide (DMPO)-spin adducts of superoxide anions in a mixture of phenylglyoxal and guanidino compounds under alkaline conditions.

Photophobia as the visual manifestation of chiasmal compression by unruptured anterior communicating artery aneurysm. Case report.

A 37-year-old woman presented with photophobia without visual loss associated with chiasmal compression by an unruptured anterior communicating artery (AcomA) aneurysm. She had suffered progressive photophobia for one year. Neuroimaging indicated an AcomA aneurysm attached to the chiasm.

Automated immunoassay system for AFP-L3% using on-chip electrokinetic reaction and separation by affinity electrophoresis.

Implementation of the on-chip immunoassay for alpha-fetoprotein (AFP)-L3% was achieved using a fully automated microfluidic instrument platform that will prepare the chip and run the assay with a total assay time of less than 10min. Reagent/sample mixing, concentration, and reaction in microfluidic channels occur by the electrokinetic analyte transport assay (EATA) technique, enabling the integration of all assay steps on-chip. The determination of AFP-L3%, a biomarker for hepatocellular carcinoma, was achieved by the presence of Lens culinaris agglutinin in the separation channel, causing separation of the fucosylated isoform, AFP-L3, from the nonfucosylated AFP-L1 by lectin affinity electrophoresis.

Electrokinetic analyte transport assay for alpha-fetoprotein immunoassay integrates mixing, reaction and separation on-chip.

A rapid and highly sensitive CE immunoassay method integrating mixing, reaction, separation, and detection on-chip is described for the measurement of alpha-fetoprotein (AFP), a liver cancer marker in blood. Antibody-binding reagents, consisting of 245-bp DNA coupled anti-AFP WA1 antibody (DNA-WA1) and HiLyte dye-labeled anti-AFP WA2 antibody (HiLyte-WA2), and AFP-containing sample were filled into adjacent zones of a chip channel defined by the laminar flow lines of the microfluidic device using pressure-driven flow. The channel geometry was thus used to quantitatively aliquot the reagents and sample into the chip.

Simultaneous occurrence of subarachnoid hemorrhage due to ruptured aneurysm and remote brainstem hematoma--case report.

A 48-year-old woman presented with simultaneous aneurysmal subarachnoid hemorrhage (SAH) and remote intracerebral hemorrhage manifesting as sudden onset of severe headache, left hemiparesis, and diplopia. Emergent computed tomography revealed localized SAH in the interpeduncular cistern, and a remote brainstem hematoma in the right dorsolateral tegment. Neuroimaging found no signs of vascular anomaly in the brainstem.

[A case of hydrocephalus in follow-up of post-traumatic subdural effusion].

We report an interesting case of hydrocephalus following traumatic subdural effusion. A 50-year-old male was diagnosed as a traumatic subdural effusion. Three months later, he was transferred to our hospital again because of conscious disturbance and incontinence.

Design and inital evaluation of a 4-layer DOI-PET system: the jPET-D4.

PET scanners are an important component in functional brain imaging devices. Several PET scanners have been developed during the last two decades for brain research studies. We are developing a high-performance brain PET scanner, jPET-D4.

Liquid-phase binding assay of alpha-fetoprotein using DNA-coupled antibody and capillary chip electrophoresis.

An immunoassay using DNA-coupled antibody for bound/free separation in a liquid-phase binding assay format is described. Anti-alpha-fetoprotein monoclonal antibody was conjugated with DNA, mixed with alpha-fetoprotein (AFP), and incubated, and then 1 muL of the mixture was applied to capillary electrophoresis on a microchip. The DNA molecule of the antibody-DNA conjugate and the DNA-conjugated immune complex peak were detectable fluorophotometrically using intercalator dye within 90 s, whereas the Alexa-labeled antibody was detected as a broad and slower migrating peak.