巻号一覧
20 巻 (2003)
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20 巻, 1 号
選択された号の論文の8件中1～8を表示しています
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再構成画像と実手術野の重畳平井 信行, 斉藤 明人, 柴崎 隆男, 伊関 洋2003 年 20 巻 1 号 p. 9-12
発行日: 2003年
公開日: 2012/08/27
ジャーナル フリーPDF形式でダウンロード (5580K) -
田中 利恵, 真田 茂, 鈴木 正行, 小林 健, 松井 武司, 井上 仁司, 中野 善久2003 年 20 巻 1 号 p. 13-19
発行日: 2003年
公開日: 2012/08/27
ジャーナル フリーDynamic chest radiographs could be obtained in a screening examination using a dynamic flat-panel detector. The dynamic images will provides not only conventional anatomical information but also respiratory kinetic information easily and cost-efficiently. The purpose of this study is to develop the method of quantitative analysis for respiratory kinetics on dynamic chest radiographs. We obtained the dynamic images of six healthy volunteers during respiration using the dynamic flat-panel detector. Our computerized method quantified the movement of diaphragm and lung markings, and the change of density in local area on these images. The results suggest that this computerized method may aid radiologist for the evaluation of lung diseases in a screening examination.抄録全体を表示PDF形式でダウンロード (2391K) -
林 則夫, 真田 茂, 鈴木 正行, 藤原 康博, 日高 国幸, 松井 武司2003 年 20 巻 1 号 p. 20-26
発行日: 2003年
公開日: 2012/08/27
ジャーナル フリーSequential wrist images were taken at 5-degree rotational interval from a pronate to supinate position (180 degrees). A tentative rotational center was obtained automatically by image analysis. We analyzed the sinogram obtained from the profile data of each image and calculated the true rotational center. Axial images were reconstructed using filtered back projection. These reconstructed images were more accurate than images that were reconstructed without analyzing the sinogram. The sinogram was derived of ulnar and radius profile data. This sinogram was used to reconstruct more accurate images.
These images are easily converted into 3D or multi planar reconstruction.
These results indicate that rotational imaging provides additional diagnostic information like 3D structure and kinetic data.抄録全体を表示PDF形式でダウンロード (3270K) -
今井 広, 春日 敏夫, 宮地 利明, 笠井 治昌, 川野 誠, 杉山 雅之2003 年 20 巻 1 号 p. 27-33
発行日: 2003年
公開日: 2012/08/27
ジャーナル フリーParallel imaging in magnetic resonance imaging (MRI) is a method to reduce the acquisition time by using phased array coils. However, there are a small number of commercial diagnostic MR imagers which could be used that method. Therefore, we developed a parallel imaging program for sensitivity encoding (SENSE). We produced sensitivity maps calculated from phantom images which was obtained with each coil element. Next, we eliminated wrap-around artifacts by using the sensitivity maps. Parallel imaging with SENSE made it possible to achieve fast scan or remove wrap-around artifacts.抄録全体を表示PDF形式でダウンロード (2225K) -
Guoyue CHEN, Binhe MIAO, Yaoqin XIE, Shanglian BAO2003 年 20 巻 1 号 p. 34-39
発行日: 2003年
公開日: 2012/08/27
ジャーナル フリーThe equal spacing in 3 dimensions (3D) is needed in many applications of medical images, which were usually processed by interpolating from the sequence of cross-sectional slices. Typically, the spacing between slices is much greater than the resolution on the slice. In order to get the equal spacing, people usually use the direct linear interpolation method based on point matching. However, the direct linear interpolation method makes the images blurred on their edges. In this paper, a new interpolation method based on optimization search for corresponding points was developed. We built up the corresponding relation between the interpolated images by optimization process, which was based on the image features with the gray value, the gradient of the gray value and the gradient direction in neighboring slices to get the paired points. Then gray value of the interpolated point in new slice was determined by linear interpolation from the paired points. The simulation results showed that our method was more accuracy than the direct interpolation methods.抄録全体を表示PDF形式でダウンロード (1899K) -
西原 貞光, 小池 正紘, 上田 克彦, 真田 泰三, 海老谷 京子, 小濱 千幸, 隅田 博臣, 飯田 忠行, 藤田 広志, 原 武史2003 年 20 巻 1 号 p. 40-43
発行日: 2003年
公開日: 2012/08/27
ジャーナル フリーWe studied the intra-and inter-equipment variations in the mean CT numbers of the central part of a vertebral body for six X-ray CT equipment. We used the lower torso phantom and the CaCO; calibration phantom. These phantoms were scanned by abdominal routine examination parameters, and the mean CT numbers of a vertebral body included in the lower torso phantom were measured. The intra-equipment variation of 1.9%(coefficient of variation: CV) for the mean CT numbers was obtained in the X-ray CT equipment. Using CaCO reference lines, we obtained the mineral contents of the vertebral body. The intra-equipment variation for the mineral contents was 2.2% (CV). The variations of the mean CT numbers and mineral contents were almost the same. The inter-equipment variation of the mean CT numbers was 4.7% (CV) and of the mineral contents was 2.8% in the six X-ray CT equipment. Therefore, we believe that the CT number obtained for a vertebral body can be used as an estimation of the bone mineral content in the X-ray CT equipment. And, if we allow interequipment variation of about 5%, we propose that the CT numbers obtained in several X-ray CT equipment can be compared.抄録全体を表示PDF形式でダウンロード (846K) -
周 向栄, 原 武史, 藤田 広志, 横山 龍二郎, 佐藤 真知子, 桐生 拓司, 星 博昭2003 年 20 巻 1 号 p. 44-47
発行日: 2003年
公開日: 2012/08/27
ジャーナル フリーA computer-aided diagnosis system that can identify the different human tissue and organ regions from CT images has been developing in our research group. In this paper, we describe the details of the extraction procedures for skin, soft tissue and skeleton regions that are the first step of the recognition process. The relationship between the different human organs and the density features of each organ region has been used in the identification process. We applied this process to 8 patient cases of multi-slice CT images; each one covers the whole torso of human body with the isotropic resolution of about 0.63 mm voxel. The experimental results showed that the procedures could recognize the target regions from the original CT images.抄録全体を表示PDF形式でダウンロード (5498K) -
篠原 範充, 藤田 広志, 原 武史, 堀田 勝平2003 年 20 巻 1 号 p. 48-51
発行日: 2003年
公開日: 2012/08/27
ジャーナル フリーThe measurement method of the characteristic curve for mammographic screen-film system has not been established due to difficulties in terms of exposure quality at low kV. In this paper we propose a bootstrap method by use of specific stepwedge for characteristic curve in mammography. The stepwedge of ten steps made from calcium phosphate with 10 different material densities was employed. The tube voltage and mAs were changed from 25kV to 32kV and from 20mAs to 100mAs, respectively, in the experiment. The results of the curves measured indicate the effectiveness of our method, although additional experiments to investigate the accuracy and precision of the data are required.抄録全体を表示PDF形式でダウンロード (2355K)
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