Publications by authors named "Koji Takasaki"

It is very important to evaluate the diameters (activity median aerodynamic diameter) of plutonium dioxide (PuO2) particles for internal exposure dose evaluation. In this study, a method of evaluating PuO2 particle diameters using an alpha-particle imaging detector was developed. PuO2 particles with different diameters were modeled by Monte Carlo simulation, and the change in the shape of the energy spectrum for each particle diameter was evaluated.

View Article and Find Full Text PDF

Objective: The aim of this study was to identify the etiology of hemifacial spasm (HFS) and trigeminal neuralgia (TN) in patients aged 30 years or younger and to examine the efficacy of microvascular decompression (MVD).

Patients And Methods: Between 1996 and 2012, 228 HFS and 190 TN patients underwent MVD at Atsuchi Neurosurgical Hospital. Of these, 7 patients were 30 years of age or younger at the time of treatment (HFS: n = 6, TN: n = 1).

View Article and Find Full Text PDF

Background: During lumboperitoneal shunt operation, we may inadvertently pull and displace the spinal catheter after the catheter placement into the spinal canal. The authors introduce an easy and efficient technique for repositioning a prolapsed catheter into correct place.

Methods: After the confirmation of cerebrospinal fluid outflow from the end of the catheter, a guidewire for angiogram was gently inserted into the catheter until its tip reached the end of the catheter.

View Article and Find Full Text PDF

Objective: The resection of foramen magnum meningiomas (FMMs) presents neurosurgical challenges. We propose a simple classification of the tumor location and the operating space created by the tumor to help treatment planning.

Methods: We retrospectively analyzed 16 FMMs and divided them into 3 groups based on the tumor location--clival, foraminal, and atlantal tumors.

View Article and Find Full Text PDF

In obese patients, we often find difficulty in laparotomy for placing a lumboperitoneal shunt catheter. The authors introduced an easy technique to get a sufficiently wide and shallow operative field through small abdominal incision in obese people. Four blunt scalp hooks and rubber bands, commonly used in craniotomy, were prepared.

View Article and Find Full Text PDF

Aneurysms associated with a fenestrated basilar artery are rare, and treatment strategies have yet to be established. A direct surgical approach to the basilar artery is challenging because the surrounding anatomy is complex. We retrospectively compared the clinical features and treatment outcomes of eight patients (seven female, one male) with aneurysms associated with a fenestrated basilar artery after clipping or coil embolisation and reviewed the literature.

View Article and Find Full Text PDF

A transition edge sensor (TES) microcalorimeter has been developed for use as an energy dispersive X-ray spectrometer. The TES microcalorimeter is a thermal detector that enables one to determine the energy of an incident photon by measuring the resultant increase in temperature. In this work, a Ti/Au TES microcalorimeter was developed to measure LX rays emitted by transuranium elements.

View Article and Find Full Text PDF

An in vivo measurement system using an imaging plate (IP) system was developed, which displayed images reflecting (239)Pu distribution in the lung of a phantom. The detection limits of the IP system for 1-12h exposures were between 1670 and 245 Bq at a 1.6 cm chest wall thickness.

View Article and Find Full Text PDF

Aneurysms located at the distal portion of the posterior inferior cerebellar artery (PICA) are rare, and their clinical features are not fully understood. We report the clinical features and management of 30 distal PICA aneurysms in 28 patients treated during the past decade at Kagoshima University Hospital and affiliated hospitals. Our series includes 20 women and eight men.

View Article and Find Full Text PDF

A new 241Am lung monitoring system without shielding was devised by using an imaging plate system. The Lawrence Livermore National Laboratory's realistic torso phantom containing a 241Am lung was covered by imaging plates sealed in lightproof bags. The imaging plate system displayed 241Am lung images characteristic of the lung shape of the torso phantom.

View Article and Find Full Text PDF