DSA System Research Articles

98. 頭部回転及び全身走行 DSA システム : その 3 レーザービデオディスクレコーダーを用いたアナログ動画像ファイリングシステム(情報管理-2)

98. 頭部回転及び全身走行 DSA システム : その 3 レーザービデオディスクレコーダーを用いたアナログ動画像ファイリングシステム(情報管理-2)

241. 頭部回転及び全身走行 DSA システム : その 1 -装置開発(DSA 装置他)

241. 頭部回転及び全身走行 DSA システム : その 1 -装置開発(DSA 装置他)

98. 頭部回転及び全身走行 DSA システム : その 3 レーザービデオディスクレコーダーを用いたアナログ動画像ファイリングシステム

98. 頭部回転及び全身走行 DSA システム : その 3 レーザービデオディスクレコーダーを用いたアナログ動画像ファイリングシステム

242. 頭部回転及び全身走行 DSA システム : その 2 使用経験(第 46 回総会学術大会会員研究発表予稿)

242. 頭部回転及び全身走行 DSA システム : その 2 使用経験(第 46 回総会学術大会会員研究発表予稿)

242. 頭部回転及び全身走行 DSA システム : その 2 -使用経験(DSA 装置他)

242. 頭部回転及び全身走行 DSA システム : その 2 -使用経験(DSA 装置他)

241. 頭部回転及び全身走行 DSA システム : その 1 装置開発(第 46 回総会学術大会会員研究発表予稿)

241. 頭部回転及び全身走行 DSA システム : その 1 装置開発(第 46 回総会学術大会会員研究発表予稿)

SR high-speed K-edge subtraction angiography in the small animal (abstract)

To assess the ability of the high-speed K-edge energy subtraction system which was made at beamline 8C of Photon Factory, Tsukuba, we performed an animal experiment. Rabbits were used for the intravenous K-edge subtraction angiography. In this paper, the actual images of the artery obtained by this system, are demonstrated. The high-speed K-edge subtraction system consisted of movable silicon (111) monocrystals, II–ITV, and digital memory system. Image processing was performed by 68000-IP computer. The monochromatic x-ray beam size was 50×60 mm. Photon energy above and below iodine K edge was changed within 16 ms and 32 frames of images were obtained sequentially. The rabbits were anaesthetized by phenobarbital and a 5F catheter was inserted into inferior vena cava via the femoral vein. 1.5 mℓ/kg of contrast material (Conlaxin H) was injected at the rate of 0.5 mℓ/kg/s. TV images were obtained 3 s after the starting point of injection. By using this system, the clear K-edge subtracted images were obtained sequentially as a conventional DSA system. The quality of the images were better than that obtained by DSA. The dynamical blood flow was analyzed, and the best arterial image could be selected from the sequential images. The structures of aortic arch, common carotid arteries, right subclavian artery, and internal thoracic artery were obtained at the chest. Both common carotid arteries and vertebral arteries were recorded at the neck. The diameter of about 0.3–0.4 mm artery could be clearly revealed. The high-speed K-edge subtraction system demonstrates the very sharp arterial images clearly and dynamically.

MTF Analysis in Digital Radiography Measurements of the Presampling MTF in a DSA system

MTF Analysis in Digital Radiography Measurements of the Presampling MTF in a DSA system

High resolution DSA: Experimental and clinical evaluation

The DSA system has been upgraded for capabilities of slow scan video technique and progressive T.V. read-out of 1024 × 1024 matrix with 10 bits of depth. A square wave test pattern made of lead bar demonstrated moderate improvement in spatial resolution, but imaging of a Burger-Rose phantom revealed no significant increase in contrast resolution. Clinical study of various angiograms with intraarterial injections showed that there was slight improvement in the visibility of the vessels, especially small arterial branches, while there was no increase in visibility of the veins. There were no cases in which diagnoses were altered by application of high resolution DSA. With future improvements of the image intensifiers, DSA with 1024 × 1024 matrix may reveal its potential advantage, especially when coupled to larger image intensifiers such as 12 or l4 in.

Hybrid digital subtraction angiography: Initial clinical experience

Hybrid digital subtraction angiography was performed after modification of a DSA system. Alternate high voltage (110–120 kV) and low voltage (65–70 kV) were obtained within short time intervals of 60–70 ms with a high voltage switching generator. Experimental phantom studies revealed the exposure dose per single image of hybrid subtraction was approximately 30% of that of conventional DSA. The SNR of hybrid subtraction was improved by increasing the exposure dose and application of postprocessing programs. Clinical application of intraarterial and intravenous DSA revealed that soft tissue artifacts were removed surprisingly well, but image quality decreased because of lowered SNR. Frame integration and matched filtering improved image quality of hybrid subtraction.

Digital Subtraction Angiography: Technology, Equipment, and Techniques

The equipment used in digital subtraction angiography is a combination of x-ray equipment and high-speed image-processing equipment. In this article, the components of a DSA system are described, including the x-ray generator, x-ray tube, image intensifier, television system, analog-to-digital (A-D) convertor, image processor, and image acquisition console, as well as available commercial equipment. Techniques for DSA examination are also discussed.

10.ステレオDSA(I.Digital Subtraction Angiographyの臨床利用について)(第12回放射線技術)

This report describes a new stereoscopic DSA system using a twin focus X-ray tube which can reconstruct a series of stereoscopic subtraction images by a single injection of contrast medium. Main points which we refer to in this paper are as follows. 1. A real-time stereoscopic view of moving images has been realized on a single TV monitor by this system. 2. A new automatic diaphragm designed for this system and some compensatory filters attached to the image intensifier provide good images without halation. 3. The digital image memories in this system are sufficient enough for large high-speed data acquisition. They are equal to the same series of images taken during conventional stereoscopic serial angiography. 4. The interfocal distance of 63 mm in the X-ray tube provides a stereoscopic pair which can be seen without a sense of incompatibility within a 1.25-fold-magnification through a 10 inch image intensifier. 5. The stereoscopic DSA is greatly appreciated for clinical application.