巻号一覧
62 巻, 7 号
選択された号の論文の15件中1～15を表示しています
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巻頭言
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加藤 英幸2006 年 62 巻 7 号 p. 62_7_I
発行日: 2006年
公開日: 2007/02/23
ジャーナル 認証ありPDF形式でダウンロード (23K)
最新技術トピックス
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2006 年 62 巻 7 号 p. 895-917
発行日: 2006年
公開日: 2007/02/23
ジャーナル 認証ありPDF形式でダウンロード (944K)
教育講座―技師が書く技師のための読影講座―
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中川 大輔2006 年 62 巻 7 号 p. 918-923
発行日: 2006年
公開日: 2007/02/23
ジャーナル 認証ありPDF形式でダウンロード (240K) -
西谷 衛2006 年 62 巻 7 号 p. 924-937
発行日: 2006年
公開日: 2007/02/23
ジャーナル 認証ありPDF形式でダウンロード (613K)
臨床技術講座
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川原 雅昭2006 年 62 巻 7 号 p. 938-947
発行日: 2006年
公開日: 2007/02/23
ジャーナル 認証ありPDF形式でダウンロード (602K)
JIRAトピックス
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細羽 実2006 年 62 巻 7 号 p. 948-950
発行日: 2006年
公開日: 2007/02/23
ジャーナル 認証ありPDF形式でダウンロード (119K)
論文
原著
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坂本 肇, 小林 寛, 池川 博昭, 大島 信二, 相川 良人, 佐野 芳知, 荒木 力2006 年 62 巻 7 号 p. 951-960
発行日: 2006年
公開日: 2007/02/23
ジャーナル フリーBecause of the more advanced and more complex procedures in interventional radiology (IVR), longer treatment times have become necessary. Therefore, it is important to determine the exposure doses received by operators and patients. Operator doses arising from the use of X-rays are mainly due to scattered radiation. The purpose of this study was to assess the feasibility of estimating operator dose by dose area product (DAP), which shows the total X-ray output from the collimator. DAP showed a strong correlation with the space dose from the fundamental examination. In clinical practice, we measured the exposure doses of the neck, left shoulder, left hand, and right finger using a thermoluminescence dosimeter (TLD). These then were compared with the DAP. The results indicated that the dose equivalents (H70 μm) of the neck and left shoulder were strongly correlated with DAP (r=0.85, 0.86), whereas the H70 μm of the left hand and right finger were less closely correlated (r=0.40, 0.48). In comparison with the fluoroscopic time, the dose equivalents showed a better correlation with DAP in all the evaluated parts. The effective doses for the operator were strongly correlated with DAP (r=0.87). When measurements are not available, dose equivalents and operator effective doses can be estimated by the DAP, as indicated by the strong correlations recognized in this study.抄録全体を表示PDF形式でダウンロード (152K) -
奈良 鉄造, 岩崎 晃, 駒井 史雄, 佐藤 和彦, 福士 英人, 洞内 美明2006 年 62 巻 7 号 p. 961-970
発行日: 2006年
公開日: 2007/02/23
ジャーナル フリーThe collimator scatter factor (ScMLC) at MLC irregular fields for high-energy X-ray irradiation is generally assumed to be equal to the jaw collimator scatter factor (Scjaw) of the square field equivalent to the rectangular field produced using pairs of jaw collimators. However, this assumption becomes strained as the ratio of the MLC equivalent square field side to the jaw collimator equivalent square field side decreases. In this study, for 4 MV and 10 MV X-rays, the collimator scatter factor (ScMLC) for an MLC irregular field could be evaluated with a high degree of accuracy using the MLC irregular correction (FMIC) factor or the jaw collimator correction (FJCC) factor.抄録全体を表示PDF形式でダウンロード (123K) -
Miwa Okumura, Takamasa Ota, Shinsuke Tsukagoshi, Kazuhiro Katada2006 年 62 巻 7 号 p. 971-978
発行日: 2006年
公開日: 2007/02/23
ジャーナル フリーTo evaluate the characteristics of edge-preserving adaptive filters for selectively eliminating noise without affecting resolution in low-dose scanning, we have developed a digital phantom image and evaluated noise statistical values, noise characteristics, and resolution characteristics. The results confirmed that edge-preserving adaptive filters function as smoothing filters in low-contrast regions containing noise, permitting the density resolution to be improved, while the strength of the smoothing filter is reduced to maintain spatial resolution in high-contrast regions containing small structures. It has therefore been confirmed that edge-preserving adaptive filters function as filters for selectively eliminating only the noise elements that are increased when the exposure dose is reduced and that such filters are effective for improving image quality. Using such digital phantom images, images acquired using conditions that are difficult to set in actual CT scanning can be obtained and images specifically for the evaluation target can easily be generated. In addition, the noise level, frequency distribution of the noise, and resolution characteristics of the objects present in the input image can be freely set. It is concluded that evaluation of processing using a digital phantom image is effective for evaluating image processing.抄録全体を表示PDF形式でダウンロード (322K) -
―明るさ知覚に関する錯視現象の画像診断への関与―辺見 秀一2006 年 62 巻 7 号 p. 979-989
発行日: 2006年
公開日: 2007/02/23
ジャーナル フリーEven if the visual impression of the photographic density of the brain in head CT images is shown as physically the same, it is known that optical illusions of lightness perception (assimilation, contrast, picture frame effect, etc.) occur and that practical density can be observed psychologically differently, according to differences in the color of the skull and background, and differences in cases (differences in picture pattern). Therefore, in this study, in order to clarify the influence of optical illusion on detectability in diagnosis, the author attempted to compare detectability in four sample cases, consisting of acute cerebral infarction (1), acute epidural hematoma (1), and chronic subdural hematoma (2), using visual subjective evaluation. In the case of acute cerebral infarction, there was no significant difference in detectability between the original image and the virtual images. Further, it clarified that the original head CT image (acute epidural hematoma) with the high-density hematoma recognized at the marginal limited part of the brain was inferior to virtual images in detectability, while it clarified that the original head CT image (chronic subdural hematoma) with the low-density hematoma was superior to virtual images in detectability, because of visual psychological emphasis on the difference of the film contrast between the hematoma and white skull.抄録全体を表示PDF形式でダウンロード (253K)
ノート
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瀬口 繁信, 西條 貴哉, 長尾 達示, 石川 芳信, 水野 昌太, 中村 覈郎2006 年 62 巻 7 号 p. 990-996
発行日: 2006年
公開日: 2007/02/23
ジャーナル フリーThe aim of this study was to assess the area of surplus X-ray radiation (surplus area) of three image intensifiers (I.I.) of two angiography X-ray units. Surplus area refers to an area surrounded with a circular collimator and effective field of view (FOV). Dose-area product (DAP) was used to measure surplus X-rays. A ratio of surplus area when based on each FOV showed an 8% to 39.3% increase with expansion of FOV, surplus area showed an 18 cm2 to 95 cm2 decrease with FOV. When the circular collimator was narrowed to a degree that could be confirmed partially in effective FOV, the rate of surplus area was decreased almost as much as the rate of scattered radiation. Surface dose was almost unchanged. The radiation exposure of the physician as well as that of the patient was reduced by the reduction of surplus area. The DAP meter, while a tool for patient radiation exposure management, is also highly useful for machinery management such as the measurement of surplus area at the I.I. system.抄録全体を表示PDF形式でダウンロード (248K) -
藤淵 俊王, 加藤 英幸, 橋本 成世, 阿部 幸直, 木川 隆司2006 年 62 巻 7 号 p. 997-1004
発行日: 2006年
公開日: 2007/02/23
ジャーナル フリーIt is important to grasp how much radiation exposure has occurred through radiation diagnosis, in respect to patient explanations and radiation protection. In this examination, we used a patient skin dosimeter (PSD) that measures entrance surface dose (ESD) in real time using a fluoroscopy procedure. The PSD has the ability to display results beginning at 1μGy. We focused our attention on the X-ray detectability of the PSD, and performed a representative evaluation with the X-ray equipment. We measured ESD under various radiographic parameters at our facility. Although the measurements were dependent on energy, we were able to measure ESD to within an accuracy of about a 5% error by putting a calibration value on energy. The PSD can measure ESD easily without requiring preparation. It is important to be aware of the exposure dose to the radiation staff, and the PSD is a very effective radiation dose-measuring tool when daily business is active.抄録全体を表示PDF形式でダウンロード (189K) -
Tsutomu Gomi2006 年 62 巻 7 号 p. 1005-1012
発行日: 2006年
公開日: 2007/02/23
ジャーナル フリーThe purpose of this study was to evaluate the clinical potential application of digital linear tomosynthesis in the imaging of hip prostheses. Volumetric x-ray digital linear tomosynthesis was used to image hip prostheses. The device used for an object of comparison assumed x-ray radiograph and computer tomography (CT) imaging. The results showed that the visualization of hip prostheses is improved by the ability to produce sectional images that blur overlying structures and yield three-dimensional (3D) information of the hip joint. The streak artifacts from the metallic components of CT devices limit the usefulness of CT in this application. The flexibility of digital linear tomosynthesis, as well as the fact that through an appropriate choice of modified filtered backprojection (FBP) algorithms it can suppress streak artifacts, potentially makes it an appropriate approach for evaluating hip prostheses. The potential of digital linear tomosynthesis in the evaluation of hip prostheses was demonstrated. Future investigations will study the ability of digital linear tomosynthesis to quantify the spatial relationships between the metallic components of these devices as well as the ability of digital linear tomosynthesis to identify bony changes of diagnostic consequence.抄録全体を表示PDF形式でダウンロード (267K)
臨床技術
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金澤 裕樹, 井上 雄介, 石田 憲一2006 年 62 巻 7 号 p. 1013-1017
発行日: 2006年
公開日: 2007/02/23
ジャーナル フリーWhen MR images are obtained with the turbo spin echo (TSE) sequence, DRIVE can be used as a sequence in which the driven equilibrium pulse (DE pulse), a reset pulse, is applied at the TSE echo train to accelerate relaxation time and return to the equilibrium of Mz magnetization. In this study, we examined the extent to which TR could be shortened in DRIVE and how the other parameters of the turbo spin echo sequence influence it. Results: 1) DRIVE is effective when the T2 value is long. 2) It is necessary to set TR at 1000 ms or more to obtain image contrast with free water and fat in T2-weighted images for which a conventional turbo spin echo sequence using DRIVE is employed in clinical examination. 3) It is not necessary to consider the influence of the TSE factor when using DRIVE.抄録全体を表示PDF形式でダウンロード (150K)
資料
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山城 尊靖, 善積 透, 小倉 明夫, 本郷 隆治, 菊元 力也2006 年 62 巻 7 号 p. 1018-1024
発行日: 2006年
公開日: 2007/02/23
ジャーナル フリーThere is a growing consensus in terms of the need for effective use of magnetic resonance imaging (MRI) diagnostic devices in emergency medical care. However, a thorough assessment of risk management in emergency medical care is required because of the high magnetic field in the MRI room. To understand the conditions required for the execution of emergency MRI examinations in individual medical facilities, and to prepare guidelines for emergency MRI examinations, we carried out a questionnaire survey concerning emergency MRI examinations. We obtained responses from 71% of 230 medical facilities and used this information in considering a system of emergency MRI examinations. Moreover, some difficulties were experienced in half of the facilities where emergency MRI examinations had been enacted, the main cause of which was the medics. Based on the results of the questionnaire, guidelines are necessary to maintain an urgent system for MRI examinations. Moreover, we were able to comprehend the current state of emergency MRI examinations in other medical facilities through this investigation, and we are preparing a system for the implementation of emergency MRI examinations.抄録全体を表示PDF形式でダウンロード (342K)
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