Biomedical subjects

Masami Azuma

Publications and source records attributed to Masami Azuma.

5 recordsLinked to original sources

PubMed2005

Usefulness of a pulse oximeter for enhancing breath holding in hepatic subtraction angiography.

This study examined the usefulness of a pulse oximeter in hepatic digital subtraction angiography (DSA) with oxygen administration for breath holding. Oxygen saturation and dissociation times were measured using a pulse oximeter. Twenty-eight patients inhaled oxygen at a rate of 3 liters/min through a nasal tube. Saturation times ranged from 0 to 140 seconds to achieve arterial oxygen-hemoglobin saturation of almost 100%. Dissociation times ranged from 0 to 600 seconds after oxygen termination.

Aged↗

PubMed2005

Verification imaging using a computed radiography system for high-energy electron beam therapy.

PURPOSE: The aim of this study was to examine a method to more conveniently acquire verification images. A computed radiography (CR) system was employed using a photostimulable phosphor plate and diagnostic cassette used for taking diagnostic X-ray photographs. MATERIALS AND METHODS: Verification images were acquired using the diagnostic cassette and therapy cassette. Image processing parameters were adjusted to improve the image quality. Verification images were printed using optimum parameters, and 10 radiation technicians visually evaluated the images. The sign test was used, and image quality was evaluated using a two-sided test at a 5% level of significance. To assess its clinical value, a radiation oncologist evaluated patient verification images. RESULTS: Verification image quality was improved by the adjustment of image processing parameters. As a result of the image quality evaluation, there were no significant differences between the two types of cassette (p>0.05). In most of the clinical cases (98%), the verification images were useful. CONCLUSION: We found that good quality verification images were acquired by a CR system with a diagnostic cassette. This system is suitable for practical use to acquire daily verification images, and it is considered useful for maintaining quality assurance (QA) in high-energy electron beam therapy.

Humans↗

PubMed2004

Relationship between smoking habits and serum oxygen radical absorbance capacity and dietary intake in Japanese adults.

1. The present study was undertaken to investigate the effect of smoking habits on dietary intake, serum oxygen radical absorbance capacity (ORAC) and lifestyle in Japanese adults. 2. Lifestyle factors were recorded by questionnaire and dietary intake was measured by a single 24 h food recall. Blood was collected under fasting conditions for analysis. 3. Smokers had lower intakes of vitamin C, fruits and dark green and yellow vegetables (DGYV), higher consumption of alcohol, lower physical activity and lower ORAC values than non-smokers. Body mass index (BMI), serum total cholesterol (TC) and triacylglycerol (TG) increased, whereas high-density lipoprotein-cholesterol (HDL-C) decreased with an increase in the amount smoked, but there were no significant differences between smokers and non-smokers. 4. It is considered that high cancer and cardiovascular risks among smokers are also reinforced by undesirable lifestyle factors other than smoking.

Adult↗

PubMed2004

[Accuracy of measurement of radiochromic film density for high-energy X-rays].

Radiochromic film (RC-film) is of great interest as a film-type dosimeter for radiation oncology applications. We present a two-dimensional image-based evaluation of the measurement accuracy of a commercial RC-film product (Gafchromic MD-55-2 film, ISP TECHNOLOGIES, Inc.) by using a commercial Laser Densitometer (Model 1710, Computerized Medical Systems, Inc.) as an optical density imaging system. The coefficient of variation of the density (pixel-value) in one sample was approximately 3% to 11% at 3 Gy or less, and 3% or less at 4 to 60 Gy. Although the coefficient of variation between three samples at the same dose was about 14% at 1 Gy, it decreased as the dose increased, reaching several percent. In 1 to 6 Gy samples, geometric imaging artifacts [interference (moire) patterns] were observed, and it was found that scan-sampling pitch influenced the accuracy of measurement of the density of the sample. To improve the accuracy of density measurement, sufficient knowledge about characteristic features of the density measuring system is essential.

Artifacts↗

PubMed2002

Bilateral anterior optic neuritis in adult measles infection without encephalomyelitis.

PURPOSE: To describe anterior optic neuritis in adult measles infection. DESIGN: Interventional case report. METHODS: A 31-year-old woman presented with bilateral visual loss 6 days after the onset of maculopapular rash. Complete ophthalmic and neurologic examinations, radiologic studies, and lumbar puncture were performed. RESULTS: Visual acuities were counting fingers in both eyes, with bilateral optic disk hyperemia and swelling noted. Neurologic examination was unremarkable, and computed tomography and magnetic resonance imaging of the brain were normal. The cerebrospinal fluid (CSF) was devoid of white cells, although measles immunoglobulin M (IgM) antibodies were detected in both CSF and serum. Intravenous corticosteroids were administered, and clinical findings resolved within 1 month. A fall in serum IgM and a rise in serum IgG titers were observed. CONCLUSIONS: Although rare, optic neuritis in the absence of encephalomyelitis may occur in measles. Whether treatment is effective is unknown.

Adult↗