Blood Flow Imaging Technique for Intravascular Ultrasound
Grant-in-Aid for Scientific Research (C)
|Allocation Type||Single-year Grants|
Biomedical engineering/Biological material science
|Research Institution||HOKKAIDO UNIVERSITY|
KUDO Nobuki Hokkaido Univ.Grad.School of Eng.Instructor, 大学院・工学研究科, 助手 (30271638)
TAKAHASHI Makoto Hokkaido Univ.Grad.School of Eng.Assistant Professor, 大学院・工学研究科, 助教授 (10154858)
YAMAMOTO Katsuyuki Hokkaido Univ.Grad.School of Eng.Professor, 大学院・工学研究科, 教授 (10088867)
|Project Period (FY)
1996 – 1997
Completed(Fiscal Year 1997)
|Budget Amount *help
¥2,400,000 (Direct Cost : ¥2,400,000)
Fiscal Year 1997 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1996 : ¥1,800,000 (Direct Cost : ¥1,800,000)
|Keywords||Medical ultrasound / Intravascular Ultrasound / Blood flow measurement / Correlation / RF signal / Atheroma / Vascular lumen|
1.RF echo processing
We developed a new time domain correlation technique for detecting displacement and velocity vectors. The technique is based on calculation of the correlation between RF echo detected by a single transducer at a fixed repetition rate. Relation between the velocity vector and correlation was derived theoretically. Advanced RF signal processing techniques for evaluation of structure and charactor of biological tissue were also discussed.
>>Transducers for IVUS
Small transducers (1.2mm * 0.8mm) which can be used in the IVUS catheter were developed. Improvement of spatial resolution and speckle reduction in the B-mode image were discussed.
>>Data acquisition and processing system
RF echo signal of the 16 sequential radial scan images is digitized into a 4 Mbyte digital data and a correlation image is processed in several minutes using personal computer. A blood flow phantom was also diveloped for in vitro experiments.
>>Measurement of flow velocity (1-D distribution)
In vitro experiments to measure the one-dimensional distribution of the flow velocity in the flow phantom were carried out. The experimental results demonstrated the practicability of the flow velocity measurement in the IVUS using the correlation technique.
>>Detection of vascular lumen (2-D imaging)
Extension of the correlation technique to the radial scan image was discussed. In this case, it is difficult to measure the flow velocity using correlation technique. However, still it is possible to get the information whether it flows or not. In vitro experiment showed that the vascular lumen was clearly identified in the radial scan image using the correlation technique.
Research Output (13results)