| Project/Area Number |
12670867
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Radiation science
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
MATSUDA Tetsuya Kyoto University, Graduate School of Informatics, Professor, 情報学研究科, 教授 (00209561)
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| Co-Investigator(Kenkyū-buntansha) |
KOMORI Masaru Shiga University of Medical Sience, Faculty of Medicine, Professor, 生命情報学, 教授 (80186824)
TAKAHASHI Takashi Kyoto University, School of Medicine, Professor, 医学研究科, 教授 (40055992)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 2001: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 2000: ¥2,000,000 (Direct Cost: ¥2,000,000)
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| Keywords | velocity measurement / phase contrast method / phase artifact / high-speed MRI / preparation pulse |
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| Research Abstract |
Magnetic resonance (MR) imaging is sensitive to blood flow and this property is clinically utilized to flow quantitation or MR angiography. Since the phase contrast method that encodes velocity to the phase of acquired MR signal has fine spatial and temporal resolution, it is now standard method to quantitate the blood flow velocity in clinical MR examinations. The phase of MR signal, however, is unstable and susceptible to many factors such as local variation of magnetic field strength and eddy currents. Therefore, conventional phase contrast method is difficult to combine with high speed MR imaging method like echo planar imaging. To accelerate the phase contrast method, we propose in this study a new technique of phase-velocity encoding that is more stable than conventional method and is able to combine with high speed imaging as a preparation pulse.
In the proposed technique, the velocity encoded phase of MR signal is once converted to longitudinal magnetization. The phase of signal is calculated from the longitudinal magnetization after the signal acquisition and the velocity information is finally retrieved. The technique was installed in a high speed MR imaging method as preparation pulse and its accuracy of velocity measurement was assessed using a steady flow phantom. The resulting measurement was proportional to the actual flow velocity, while the proportional constant depended on the T1 value. Though the correction of velocity measurements using T1 value was required, the proposed technique successfully quantitated the flow velocity. Since it can be used as preparation pulse, the new technique realizes a high-speed measurement of flow velocity.
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