巻号一覧
49 巻 (2009)
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49 巻, 1 号
選択された号の論文の3件中1～3を表示しています
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原著
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岡村 和俊, 吉浦 一紀, 辰見 正人2009 年 49 巻 1 号 p. 1-6
発行日: 2009年
公開日: 2009/08/05
ジャーナル フリーMore than 15 years have passed since a first digital intraoral imaging system was commercialized and there was some improvement in some systems. We evaluated one of the improved intraoral digital imaging systems, Digora Optime, by comparing its image quality and physical characteristics with that of the old model, quantitatively. Whereas the gray level of primal Digora was almost linearly decreased with exposure, that of the Digora Optime was almost logarithmically decreased with exposure and similar to the characteristic curve of typical intraoral film systems. In image quality evaluation using a test object by 11 observers, the detectability of the Digora Optime exceeded that of the old one with lower exposure. In addition, similar results were obtained in evaluation of image quality with the simulated human mandible phantom. It was considered that Digora Optime could be a very useful tool in clinical practice.抄録全体を表示PDF形式でダウンロード (447K) -
―localizer imageについて―岡村 和俊, 吉田 豊, 辰見 正人, 加藤 誠, 中山 英二, 徳森 謙二, 吉浦 一紀2009 年 49 巻 1 号 p. 7-12
発行日: 2009年
公開日: 2009/08/05
ジャーナル フリーComputed tomography (CT) is one of the main sources of medical radiation exposure. In addition, the recent trend towards higher image quality may lead to further increase of the patient dose. Though the exposure dose reduction of the patient is an important issue, dose reduction may lead to low image quality. Possible solution may be reduction of unnecessary images. Therefore, we evaluated the dosage of the localizer image that does not contribute to a diagnosis directly. The dose was measured using a human head & neck Rando Phantom (Alderson Research Laboratories, USA) in the localizer scan with CT scanner Aquilion (Toshiba Medical, Japan). Thermo-Luminescence-Dosimeters (TLD) were set on eyes, pituitary gland, parotid glands, submandibular glands, thyroid gland and skin surface. All scans were obtained at 120 kV and the tube current was decreased from 200 mA to 10 mA. The dose of a localizer image accounted for a large ratio in head & neck CT examination. The organ dose decreased in proportion to tube current and the head & neck localizer image obtained with 10mA was found to be acceptable. In evaluation by radiological technologists, all the landmarks could be confirmed even in the lowest setting. It was suggested that dose reduction of the localizer image can contribute to the total dose reduction.抄録全体を表示PDF形式でダウンロード (440K)
写真供覧
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荒木 正夫, 雨宮 俊彦, 松本 邦史, 本田 和也, 清崎 丈司2009 年 49 巻 1 号 p. 14-15
発行日: 2009年
公開日: 2009/08/05
ジャーナル フリーPDF形式でダウンロード (349K)
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