著者
宮井 將宏 山本 泰司 内部 拓 矢田 伸広 原元 益夫 勝部 敬 北垣 一
出版者
公益社団法人 日本放射線技術学会
雑誌
日本放射線技術学会雑誌 (ISSN:03694305)
巻号頁・発行日
vol.71, no.12, pp.1209-1214, 2015 (Released:2015-12-20)
参考文献数
15
被引用文献数
3 3

In the dopamine transporter scintigraphy there are two quantitative analysis softwares, DaTView and DaTQUANT. The quantitative value of both software has to be treated independently because there is a difference between them in the point of how to set the region of interest on the striatum and the background, calculation formula of quantitation. And also DaTQUANT has a capability of performing anatomical standardization which DaTView does not have. The aim of this study was to evaluate the accuracy of registration on DaTQUANT using a phantom, and to evaluate the correlation between the quantitative values between DaTView and DaTQUANT using clinical data. As a result, the accuracy of registration was acceptable. Regardless of the degree of accumulation in the striatum, there was a high correlation to each analysis software (r>0.85).
著者
栗山 巧 坂井 信幸 新井田 紀光 古川 宗 大西 久美子 三上 朋子 奥町 英世 今村 博敏 坂井 千秋
出版者
Japanese Society of Radiological Technology
雑誌
日本放射線技術學會雜誌 (ISSN:03694305)
巻号頁・発行日
vol.68, no.12, pp.1652-1661, 2012-12-20
参考文献数
23
被引用文献数
1

<i>Purpose</i>: We made the fusion image of both stent and platinum coil after embolization of an unruptured aneurysm. <i>Method</i>: After scanning with cone beam computed tomography, we made three dimensional (3D) images of stent and coil and fused them. <i>Conclusion</i>: We can evaluate unruptured aneurysm after embolization by using a fusion image. 3D-fusion image is useful on clinical cases.
著者
栗山 巧 古川 宗 清水 敬二 大西 久美子 酒井 慎治 今村 博敏 坂井 千秋 坂井 信幸
出版者
Japanese Society of Radiological Technology
雑誌
日本放射線技術學會雜誌 (ISSN:03694305)
巻号頁・発行日
vol.68, no.1, pp.95-102, 2012-01-20
参考文献数
13
被引用文献数
1

We compared the accuracy in evaluating an unrapture aneurysm between NV and 3D-DSA. In vitro, we evaluated the accuracy in calculating the volume of the Aneurysm model. We compared the diameter of the first coil and estimated the diameter of the Aneurysm. The Aneurysm size calculated by NV resembled the first coil more than the size measured by 3D-DSA. In clinical cases, the measurement of NV is objective; the measurement of 3D-DSA, however, is subjective by person. NV has an automatic measurement that is useful for clinical cases.
著者
栗山 巧 坂井 信幸 古川 宗 大西 久美子 奥町 英世 今村 博敏 坂井 千秋
出版者
Japanese Society of Radiological Technology
雑誌
日本放射線技術學會雜誌 (ISSN:03694305)
巻号頁・発行日
vol.69, no.11, pp.1232-1240, 2013-11-20
参考文献数
15
被引用文献数
1

<i>Background</i>: In coil embolization of neurovascular aneurysms, we have noted that few wide-necked unruptured aneurysms are successfully embolized. This prompted us to search for useful factors to assist the choice of methods of coil embolization. <i>Method</i>: We first measured aneurysm size and volume using auto measurement (NVvol) and VER (NVver). Second, we calculated the volume (NVapp) and VER (NVapp) using approximation expressions. Third, we measured the end-on view neck angle using a 3 dimensional digital subtraction angiography (3D-DSA) image. <i>Results</i>: NVvol and NVapp were correlated (<i>y</i>=0.87<i>x</i>). NVvol VER and NVapp VER approached 24% in 41 clinical cases. The dome/neck ratio averaged 1.15. Length of neck and the end-on view neck angle were significantly different between the stent-assisted group and the balloon-assisted group. NVvol and NVapp showed a good correlation with basic examination results in 41 clinical cases. <i>Conclusion</i>: The end-on view neck angle is significantly different. This boundary neck angle was 100° for the two groups. The end on-view neck angle is thus a useful factor for deciding medical treatment strategy.
著者
山口 功 石田 智一 木戸屋 栄次 東村 享治 鈴木 正行
出版者
公益社団法人日本放射線技術学会
雑誌
日本放射線技術學會雜誌 (ISSN:03694305)
巻号頁・発行日
vol.61, no.2, pp.260-267, 2005-02-20
被引用文献数
7

A strict determination of scan timing is needed for dynamic multi-phase scanning and 3D-CT angiography (3D-CTA) by multi-detector row CT (MDCT). In the present study, contrast media arrival time (T_<AR>) was measured in the abdominal aorta at the bifurcation of the celiac artery for confirmation of circulatory differences in patients. In addition, we analyzed the process of formation of the time-density curve (TDC) and examined factors that affect the time to peak aortic enhancement (T_<PA>). Mean T_<AR> was 15.57±3.75 s. TDCs were plotted for each duration of injection. The rising portions of TDCs were superimposed on one another. TDCs with longer injection durations were piled up upon one another. Rise angle was approximately constant in response to each flow rate. Rise time (T_R) showed a good correlation with injection duration (T_<ID>). T_R was 1.01T_<ID> (R^2=0.994) in the phantom study and 0.94T_<ID>-0.60 (R^2=0.988) in the clinical study. In conclusion, for the selection of optimal scan timing it is useful to determine T_R at a given point and to determine the time from T_<AR>.
著者
浜口 直子 小寺 秀一
出版者
公益社団法人 日本放射線技術学会
雑誌
日本放射線技術学会雑誌 (ISSN:03694305)
巻号頁・発行日
vol.66, no.4, pp.313-321, 2010-04-20 (Released:2010-07-08)
参考文献数
10
被引用文献数
3 5

It is a fact that image noise influences for image qualities of the brain CT are known widely. The same principle applies to 3D-CTA, image noise significantly influences the depiction of blood vessels. So we evaluated the use of CT-AEC for 3D-CTA to optimize the scan dose and control the depiction of cerebral vessels by CT-AEC. We decided to optimize the noise index (NI) for cerebral 3D-CTA through the use of an imitation blood phantom. In the evaluation of the depiction of the anterior choroidal artery that was able to be confirmed with DSA, the detection rate in high resolution mode: NI 6.0 was 70%. The depiction of the anterior choroidal artery became defective in the detailed exam mode: NI 7.0, low dose mode: NI 9.0 because of the noise. As for the existence of cerebral aneurysms, the sensitivities were 100% with DSA and 94.3% with 3D-CTA in detailed exam mode, and there was no statistical difference. The specificities of 3D-CTA had lowered to 92.6% and 97.2% in DSA. In low dose mode and detailed exam mode, DLP had decreased by 55.2% and 18.1% on the average compared to a fixed tube current (P<0.05). However, in high resolution mode, DLP increased by 5.9% on the average. It was necessary to limit the scan range to the region of interest when we used a fixed tube current. This clinical research verified that CT-AEC on cerebral 3D-CTA was useful for dose reduction and control of the depiction ability for inspection purposes.
著者
井上 健 市川 勝弘 原 孝則 瓜倉 厚志 星野 貴志 三浦 洋平 寺川 彰一 宇都 文昭
出版者
公益社団法人 日本放射線技術学会
雑誌
日本放射線技術学会雑誌 (ISSN:03694305)
巻号頁・発行日
vol.68, no.12, pp.1631-1636, 2012-12-20 (Released:2012-12-20)
参考文献数
12
被引用文献数
3 1

Iterative reconstruction methods can reduce the noise of computed tomography (CT) images, which are expected to contribute to the reduction of patient dose CT examinations. The purpose of this study was to investigate impact of an iterative reconstruction method (iDose4, Philips Healthcare) on vessel visibility in coronary CT angiography (CTA) by using phantom studies. A simulated phantom was scanned by a CT system (iCT, Philips Healthcare), and the axial images were reconstructed by filtered back projection (FBP) and given a level of 1 to 7 (L1-L7) of the iterative reconstruction (IR). The vessel visibility was evaluated by a quantitative analysis using profiles across a 1.5-mm diameter simulated vessel as well as visual evaluation for multi planar reformation (MPR) images and volume rendering (VR) images in terms of the normalized-rank method with analysis of variance. The peak CT value of the profiles decreased with IR level and full width at half maximum of the profile also decreased with the IR level. For normalized-rank method, there was no statistical difference between FBP and L1 (20% dose reduction) for both MPR and VR images. The IR levels higher than L1 sacrificed the spatial resolution for the 1.5-mm simulated vessel, and their visual vessel visibilities were significantly inferior to that of the FBP.
著者
稲本 一夫
出版者
公益社団法人日本放射線技術学会
雑誌
日本放射線技術學會雜誌 (ISSN:03694305)
巻号頁・発行日
vol.51, no.9, pp.1275-1280, 1995-09-01
被引用文献数
1
著者
小倉 敏裕
出版者
公益社団法人日本放射線技術学会
雑誌
日本放射線技術學會雜誌 (ISSN:03694305)
巻号頁・発行日
vol.49, no.12, pp.2052-2057, 1993-12-01
被引用文献数
4

1.解像特性は, 同一インチモードにおいてもアイリス径とピクセル値がそれぞれ大きくなると低下することがわかった.このことは, I.I.への入射線量の増減により解像特性が変化することを意味する.aアイリス径を一定に保ち, 入射線量を増すとピクセル値が上昇し解像特性が低下する.bピクセル値を一定に保つためにアイリス径を広くし, 入射線量を減ずると解像特性が低下する.すなわち, 高い解像特性の画像を得るためには, アイリス径を絞り, 低いピクセル値となるような線量で撮影する.逆にあまり高い解像特性を必要としない場合, アイリス径を広くすることによって被曝低減が可能である.2.低線量撮影により, ルーチンに小焦点(0.2mm)撮影が可能である.このため, 小焦点拡大撮影の技法が応用でき, S/Fに匹敵する解像特性の有する画像が得られる.3.ノイズに関して, 線量の低減によって量子モトルが増加し, ディジタルWSは上昇した.そして, 同時に低コントラスト被写体検出能の低下も顕著であった.また, ノイズ特性は, 解像特性と密接な関係があるため, アイリス径や, ピクセル値によっても異なる.このように, I.I./TV-DRの場合, 入射線量と解像特性とノイズ特性の間には, 複雑な関係があり, これらの特性を熟知したうえで撮影目的にあったDR装置のパラメータの設定, 線量, 撮影方法を決定する必要がある.
著者
大江 光雄 小倉 一郎 鈴木 亘
出版者
公益社団法人日本放射線技術学会
雑誌
日本放射線技術學會雜誌 (ISSN:03694305)
巻号頁・発行日
vol.46, no.8, 1990-08-01

センターライン法のアルゴリズムを改良して良好な結果を得た。また正常例の解析結果を蓄積した。本開発に協力いただいた国立循環器病センター放射線技師の大西先生に感謝致します。