Endovascular Treatment for Basilar Artery Occlusion Caused by Radiation-induced Vertebral Artery Stenosis: Case Report

Objective: We report endovascular treatment of a patient with acute basilar artery occlusion considered to be due to an embolus from radiation-induced vertebral artery stenosis.Case Presentation: The patient was a 46-year-old male with a history of neck irradiation. He developed basilar artery occlusion. Temporary recanalization achieved by intravenous alteplase therapy and revascularization was followed by relapse. The origin of the vertebral artery was stenosed, and basilar artery was considered to have been embolized by a thrombus formed on the proximal side of the vertebral artery, where blood flow was stagnated due to reduced antegrade flow from the distal side of the stenotic vertebral artery and the increased collateral flow from the deep cervical artery. Recurrence of cerebellar infarction could be prevented by revascularization and occlusion of the parent artery.Conclusion: Acute basilar artery occlusion considered to be due to an embolus from radiation-induced vertebral artery stenosis is a rare condition, but it must be recognized as a possible cause of posterior circulation infarction

Cosmic ray nuclei detection in the balloon borne nuclear emulsion gamma ray telescope flight in Australia (GRAINE 2015)

Nuclear emulsion plates for studying elementary particle physics as well as cosmic ray physics are very powerful tracking tools with sub-micron spatial resolutions of charged particle trajectories. Even if gamma rays have to be detected, electron-positron pair tracks can provide precise information to reconstruct their direction and energy with high accuracy. Recent developments of emulsion analysis technology can digitally handle almost all tracks recorded in emulsion plates by using the Hyper Track Selector of the OPERA group at NAGOYA University. On the other hand, the potential of time resolutions have been equipped by emulsion multilayer shifter technology in the GRAINE (Gamma Ray Astro-Imager with Nuclear Emulsion) experiments, the aims of which are to detect cosmic gamma rays such as the Vela pulsar stellar object by precise emulsion tracking analysis and to study cosmic ray particle interactions and chemical compositions. In this paper, we focus on the subject of cosmic ray nuclei detection in the GRAINE balloon flight experiments launched at Alice Springs, Australia in May 2015

Cosmic ray nuclei detection in the balloon borne nuclear emulsion gamma ray telescope flight in Australia (GRAINE 2015)

Nuclear emulsion plates for studying elementary particle physics as well as cosmic ray physics are very powerful tracking tools with sub-micron spatial resolutions of charged particle trajectories. Even if gamma rays have to be detected, electron-positron pair tracks can provide precise information to reconstruct their direction and energy with high accuracy. Recent developments of emulsion analysis technology can digitally handle almost all tracks recorded in emulsion plates by using the Hyper Track Selector of the OPERA group at NAGOYA University. On the other hand, the potential of time resolutions have been equipped by emulsion multilayer shifter technology in the GRAINE (Gamma Ray Astro-Imager with Nuclear Emulsion) experiments, the aims of which are to detect cosmic gamma rays such as the Vela pulsar stellar object by precise emulsion tracking analysis and to study cosmic ray particle interactions and chemical compositions. In this paper, we focus on the subject of cosmic ray nuclei detection in the GRAINE balloon flight experiments launched at Alice Springs, Australia in May 2015

First Emulsion γ-Ray Telescope Imaging of the Vela Pulsar by the GRAINE 2018 Balloon-borne Experiment

We are developing the Gamma-Ray Astro-Imager with Nuclear Emulsion project, designed for 10 MeV–100 GeV cosmic γ-ray observations with a high angular resolution (5'/0:[fdg]08 at 1–2 GeV) and a polarization-sensitive large-aperture (∼10 ㎡) emulsion telescope for repeated long-duration balloon flights. In 2018, a balloon-borne experiment was carried out in Australia with a 0.38 ㎡ sensitive area and a flight duration of 17.4 hr, including 6.7 hr of Vela observations. Significant improvements compared with the 2015 balloon-borne experiment were achieved by a factor of 5, including both an increase in effective area × time and a reduction in the background contribution. We aimed to demonstrate the telescope's overall performance based on detection and imaging of a known γ-ray source, the Vela pulsar. A robust detection of the Vela pulsar was achieved with a 68% containment radius of 0:[fdg]42, at a significance of 6σ, at energies above 80 MeV. The resulting angular profile is consistent with that of a pointlike source. We achieved the current best imaging performance of the Vela pulsar using an emulsion γ-ray telescope with the highest angular resolution of any γ-ray telescope to date