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Estimation of Regional Myocardial Blood Flow by Trans Venous Micro-bubble and Two Dimensional Low Frequency Doppler

经静脉微泡和二维低频多普勒估计局部心肌血流量

基本信息

批准号：
07680939
负责人：
SEKIOKA Kiyotsugu
金额：
$ 1.41万
依托单位：
Mie University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07680939/
关键词：
Micro-bubble Harmonic Imaging Decay of Back Scatter Ultrasonic 崩壊超音波エコー周波数スペクトル micro bubble myocardial perfusion doppler

项目摘要

To utilize non-linear character of micro-bubbles for ultrasonic visualization of tissue perfusion, fundamental characters of micro-bubbles were studied on Albunex, SHU508A,QW3600 and F-04E (PVC-AN). Radio-frequency (RF) signals of backscatter from micro-bubbles or/and Doppler signal were digitized with 12bit A/D converter. Power spectra of RF and Doppler shift were calculated. B-mode scan with 2.5 and 3.5MHz scanner or doppler sampling with 2.0 and 2.5MHz probe and variable pulse repetition rates were performed. Decay of power spectra and fundamental/second harmonic ratio were observed. Digitized RF signal were Hilbert transformed with Fourier transformation and frequency band-pass filtering to carrier (fundamental) and 2nd harmonic. From B-mode image representing regional amplitude of back scatter obtained with Hilbelt transform, the region of micro-bubble was selected. The amplitude of back scatter in dB was exponentially decreased with continuous scan. The decay of backscatter was the largest in Albunex under 2.5MHz scan. SHU508A and F-04E showed similar exponential decay with smaller velocity. In all micro-bubbles, the absolute backscatter and the ratio of the second harmonic/fundamental (.186 to .371) were larger in 2.5MHz than in 3.5MHz. The decay was also larger in 2.5MHz. QW3600 showed quite slow decay of backscatter with durability to ultrasound exposure, compared to the other three bubbles. The decay of carrier frequency and 2nd harmonic was not identical in Albunex under 2.5MHz.

为了利用微泡的非线性特性对组织灌注进行超声显示，研究了Albunex、SHU508A、QW3600和F-04E （PVC-AN）微泡的基本特性。利用12位A/D转换器对微气泡的后向散射射频信号和多普勒信号进行数字化处理。计算了射频功率谱和多普勒频移。采用2.5和3.5MHz扫描器进行b模式扫描，或采用2.0和2.5 mhz探针进行多普勒采样，采用可变脉冲重复率。观察到功率谱和基次谐波比的衰减。数字化后的射频信号经傅里叶变换和带通滤波后得到载波（基频）和二次谐波。从Hilbelt变换得到的表示后向散射区域振幅的b模图像中选择微气泡区域。连续扫描后，后向散射振幅呈指数级下降。在2.5MHz扫描下，Albunex的后向散射衰减最大。SHU508A和F-04E表现出相似的指数衰减，但衰减速度较小。在所有的微气泡中，绝对后向散射和二次谐波/基波之比(。186 . to。371)在2.5MHz下比在3.5MHz下更大。在2.5MHz时衰减也更大。与其他三个气泡相比，QW3600在超声波暴露下的后向散射衰减速度相当慢。在2.5MHz下，Albunex的载频衰减和二次谐波衰减并不相同。