Renal Blood Flow Quantification in Pigs Using Contrast-Enhanced Ultrasound: An Ex Vivo Study
Renal Blood Flow Quantification in Pigs Using Contrast-Enhanced Ultrasound: An Ex Vivo Study
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DOI：
10.1055/s-0029-1245238
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发表时间：
2010-08-01
影响因子：
3.4
通讯作者：
Correas, J. -M.
中科院分区：
文献类型：
--
作者：
Hoeffel, C.;Mule, S.;Correas, J. -M.
目的：本研究的目的是评估一种新的方法，用于定量的肾血流量使用造影增强超声（CEUS）在离体猪肾模型。材料和方法：经动物伦理委员会批准后，将4个猪肾用Celsior（R）液体灌注（Imtix Sangstat，里昂，法国）在离体模中以不同流速（30、50、70和90 ml/min）进行。以0.5 ml/min的速度将SonoVue（R）（Branca，Milano，意大利）的50%稀释溶液注入动脉。使用Aplio系统（Toshiba，Nasu，Japan）进行CEUS，使用宽带线性换能器和脉冲减影成像。共采集了152个破坏-再灌注序列，并将电影回放数字化存储以供进一步量化。将三种不同的ROI放置在前、后皮质和节段动脉上。以线性单位进行信号强度测量，并使用专用软件自动提取灌注参数。使用单指数模型进行曲线拟合，其中引入了时间延迟参数。该拟合允许评估进入感兴趣区域的局部血流（称为“对比增强血流”（CEBF））。动脉平均信号强度从破坏阶段之前的10帧求平均。标准化CEBF（nCEBF）计算为CEBF与平均动脉信号强度之间的比值。将CEBF和nCEBF与泵流速指示的真实血流量进行比较。结果：CEBF仅与后皮质ROI的真实血流相关（R-2 = 0.45，p = 0.05）。使用动脉信号的标准化改善了CEBF与真实血流的相关性：当考虑所有ROI时，nCEBF与真实血流相关（R-2 = 0.94，p < 0.0001），并且前部和后部皮质ROI的相关性均得到改善（分别为R-2 = 0，93，p = 0.0004; R-2 = 0，90，p = 0.0005）。然而，在前皮质ROI（p = 0.017）中观察到显著的肾脏依赖性效应，但在后皮质ROI（p = 0.89）中未观察到。结论：使用动脉信号的归一化显著改善了CEUS计算的血流估计。
Purpose: The aim of the study was to evaluate a new method for the quantification of renal blood flow using contrast-enhanced ultrasound (CEUS) in an ex vivo pig kidney model.Material and Methods: After approval by the animal ethics committee, 4 pig kidneys were explanted and perfused with Celsior (R) liquid (Imtix Sangstat, Lyon, France) at different flow rates (30, 50, 70 and 90 ml/min) in an ex vivo phantom. A50% diluted solution of SonoVue (R) (Bracco, Milano, Italy) was infused in the artery at 0.5 ml/min. CEUS was performed with an Aplio system (Toshiba, Nasu, Japan) using a broadband linear transducer and pulse subtraction imaging. A total of 152 destruction-reperfusion sequences were acquired and cine loops were digitally stored for further quantification. Three different ROIs were placed upon the anterior, posterior cortex and segmental artery. Signal intensity measurements were performed in linear units and perfusion parameters were automatically extracted using dedicated software. Curve fitting was performed using a monoexponential model in which a time delay parameter was introduced. This fit allowed the assessment of the local blood flow into the region of interest (called "contrast-enhanced blood flow" (CEBF)). The artery mean signal intensity was averaged from the ten frames prior to the destruction phase. The normalized CEBF (nCEBF) was calculated as the ratio between CEBF and the mean arterial signal intensity. The CEBF and nCEBF were compared to the true blood flow indicated by the pump flow rate. Results: The CEBF was correlated to the true blood flow only for the posterior cortical ROI (R-2 = 0.45, p = 0.05). The normalization using arterial signals improved CEBF correlation to true blood flow: nCEBF became correlated to the true blood flow when considering all ROIs (R-2 = 0.94, p < 0.0001) and correlation was improved for both anterior and posterior cortical ROIs (R-2 = 0, 93, p = 0.0004; R-2 = 0, 90, p = 0.0005, respectively). However, a significant kidney-dependent effect was observed for the anterior cortical ROI (p = 0.017) but not for the posterior cortical ROI (p = 0.89). Conclusion: Normalization using arterial signals significantly improved the estimation of blood flow calculated with CEUS.