灰阶超声造影对兔荷VX2瘤前后肝实质血流灌注的对照研究

目的应用灰阶超声造影定量研究肝恶性肿瘤对其周围肝实质血流动力学的影响及其诊断价值.方法分别经耳缘静脉对8只新西兰大白兔荷VX2瘤前、后团注超声造影剂SonoVueTM(0.1 ml/kg),应用CnTi(contrast tuned imaging) 低机械指数实时灰阶造影调谐成像技术和声学定量时间强度曲线分析软件,定量分析兔荷瘤前、后肝实质造影增强效应.结果在造影过程中,肿瘤及肝实质内造影剂随时间呈动态增强,其时间-信号强度曲线客观反映造影剂显影的全过程.与荷瘤前相比,荷瘤后肝实质造影剂开始增强时间和达到峰值时间均较早,峰值强度较强,显影时间短,但其变化轻微.荷瘤前、后肝实质各造影定量参数间差异均无显著性意义(P>0.05).结论灰阶超声造影不能完全反映肝恶性肿瘤对其周围肝实质血流动力学影响;肝实质超声造影定量分析对肝恶性肿瘤的诊断及预示价值尚待进一步研究.     

低机械指数灰阶造影对肝VX2瘤动态期相性变化的研究

目的应用低机械指数灰阶超声造影研究肝恶性肿瘤的动态期相性增强变化规律及其诊断价值。方法分别经耳缘静脉对8只荷VX2瘤新西兰大白兔团注超声造影剂SonoVue（0．1ml／kg），应用CnTI低机械指数实时造影匹配成像技术，动态观察兔VX2瘤及其周围肝实质造影增强效应。结果在所有造影过程中，肝肿瘤及肝实质内造影剂随时间呈动态增强。VX2瘤动脉期明显强化，呈“灯泡征”，与周围肝组织灰阶对比明显；随后造影剂逐渐退出，肿瘤回声强度从与周围肝实质持平，到低于周围肝实质，最后造影剂完全退出瘤组织，在肝实质增强的背景下呈极低回声。肿瘤强化呈“快进快出”型。结论VX2瘤主要为肝动脉供血，具有恶性肿瘤“快进快出”典型的超声造影增强特点；低机械指数灰阶超声造影能完全反映肝恶性肿瘤血流动力学变化；观察肿瘤的动脉期是超声造影的关键，对诊断及鉴别诊断具有重要意义。     

左、右半肝不同部位灰阶超声造影的定量研究

目的 研究左、右半肝不同部位肝实质灰阶超声造影效应及其造影定量参数的差异。 方法 团注法经耳缘静脉分别对10只新西兰大白兔注入超声造影剂Sono Vue^TM，应用CnTi低机械指数实时灰阶造影匹配成像技术和声学定量时间一强度曲线分析（Wash-in／Wash-out）软件，定量分析左、右半肝边缘部位及中心部位肝实质造影增强效应。 结果 造影剂在肝内呈动态增强过程。（1）与边缘部位肝实质相比，中心部位肝实质造影剂开始增强时间和达到峰值时间均较早，峰值强度较强，渡越时间较长。除左肝造影剂渡越时间外，中心部位与边缘部位肝实质各造影定量参数间差异具有显著性意义（P〈0．05）；（2）与左半肝相比，右半肝中心部位及边缘部位肝实质造影剂开始增强时间和达到峰值时间均较早，峰值强度较强，渡越时间较长。除边缘部位的造影剂开始增强时间外，左、右半肝肝实质造影定量参数间差异具有显著性意义（P〈0．05）。 结论 左、右半肝肝实质灰阶超声造影定量参数不同；在同一半肝内，边缘部位与中心部位肝实质超声造影定量参数亦不同。在对肝脏病变进行定量研究时，考虑到这种差异及病变的生长部位对临床诊断和鉴别诊断意义重大。     

肝不同部位灰阶超声造影定量分析的实验研究

目的　研究肝不同部位灰阶超声造影效应及其规律。方法　分别经耳缘静脉对 8只新西兰大白兔团注超声造影剂 ,应用低机械指数灰阶超声造影和时间强度曲线 ,定量分析边缘部位及中心部位肝实质造影增强效应。结果　与边缘部位肝实质相比 ,中心部位肝实质造影剂开始增强时间和达到峰值时间均较早 ,峰值强度较强 ,渡越时间较长 ,曲线下面积较大。除左肝造影剂渡越时间外 ,肝脏中心部位与边缘部位各造影定量参数间差异有显著性意义 (P <0 .0 5 )。结论　边缘部位及中心部位肝实质超声造影定量参数不同 ,在讨论造影定量指标如造影开始时间、峰值强度、曲线下面积等时 ,与定量部位及病变性质相联系来研究 ,对临床诊断和鉴别诊断价值更大。     

肝灰阶超声造影剂量与效果关系的实验研究

目的 探讨不同超声造影剂剂量对肝灰阶超声造影效果的影响及其变化规律。方法 分别对5只新西兰大白兔在8个剂量水平(剂量范围：0．02～0．16ml／kg)团注超声造影剂，应用低机械指数灰阶超声造影和时间强度曲线定量分析门静脉和肝实质造影增强效果。结果 门静脉和肝实质开始增强时间随造影剂剂量的增加而缩短，均呈指数递减形式；造影剂剂量与门静脉、肝实质峰值增强时间无明确相关性(r=-0．35，0．22)；在0．02～0．10ml／kg范围内，造影剂剂量与门静脉、肝实质峰值信号强度呈直线相关关系(r=0．89，0．92)；门静脉和肝实质的平均渡越时间和曲线下面积均随造影剂剂量的递增而增加，呈指数递增形式。结论 超声造影剂剂量影响肝造影增强各参数。确定剂量和效果的关系及认识其规律是进行超声造影和定量研究的前提条件。0．10ml／kg是兔理想的造影剂量。     

超声造影评价兔肝炎性假瘤及VX2肝癌血流灌注的实验对照研究

目的 应用实时超声造影成像技术及时间-强度曲线,观察兔肝炎性假瘤和转移性VX2肝癌的血流灌注方式.方法 荷炎性假瘤和荷VX2肝癌实验兔各10只,经耳缘静脉团注法注射超声造影剂SonoVue后,应用CnTI低机械指数实时灰阶成像技术和定量时间-强度曲线(Wash in-Wash out Curve)软件,观察分析各时相肿瘤结节及周围正常肝组织的动态增强过程.结果 与正常肝实质相比较,炎性假瘤造影增强与肝实质同步,二者造影始增时间、峰值时间、增强时间、始消时间无显著性差别(P>0.05).VX2肝癌强化呈典型的"快进快出"型,早期动脉相快速增强,门脉相与延迟相肿瘤结节内造影剂迅速廓清,表现为负性显影,VX2肝癌始增时间、峰值时间、增强时间、始消时间显著早于正常肝实质(P<0.05).VX2肝癌与炎性假瘤比较,VX2肝癌造影始增时间、峰值时间、始消时间显著早于炎性假瘤(P<0.05).结论 低机械指数实时超声造影成像,可提供肝脏局灶性结节的动态血流灌注信息,结合时间-强度曲线定量分析,对肝肿瘤的诊断和鉴别诊断具有较佳的实用价值.     

实时超声造影在正常移植肝血流动力学研究中的应用

目的：应用实时超声造影定量研究正常移植肝的灌注，并与正常人肝脏灌注特点比较，总结移植肝的血流动力学特征。方法：选取原位肝移植术后临床指标正常的患者30例，健康志愿者35例，分别对肝脏行实时造影及声学定量分析，比较肝实质的灌注及血流动力学特点。结果：实时超声造影可动态显示肝实质内造影剂的增强过程，其时间一信号强度曲线客观反映造影剂的渡越过程。正常移植肝组与健康人组肝动脉显影时间、门静脉显影时间、肝静脉显影时间、肝动静脉渡越时间，肝动脉－门静脉渡越时间、肝实质开始显影时间、增强峰值时间、峰值强度等与健康人组均无显著差异。结论：本研究初步结果显示移植肝的灌注特征与正常肝脏一致，利用超声造影肝脏灌注显像对移植肝并发症的诊断时，可以考虑采用正常肝脏的指数。     

经门静脉低机械指数灰阶超声造影在肝肿瘤中的应用

目的：应用经门静脉低机械指数灰阶超声造影研究肝恶性肿瘤门静脉供血特点。方法：分别经门静脉主干对12只荷VX2瘤新西兰大白兔快速注射超声造影剂Sono Vue，应用CnTi（contrast tuned imaging）低机械指数实时灰阶造影匹配成像技术，分析22个VX2瘤门静脉供血特点与造影增强效应。结果：注射造影剂后肝实质快速强化并很快达到高峰，而肿瘤一般延迟3～6s后才开始增强。门静脉造影22个肿瘤增强可分4种类型：①弥漫增强型7例，表现为肿瘤弥漫性增强，但其增强效应比周围肝实质的强烈增强弱，仍呈负性显影；②门静脉分支型3例，表现为肿瘤内出现门静脉分支影，造影剂微泡在其内快速流动，肿瘤实质仅轻微增强；③周边增强型5例，表现为肿瘤周边不规则增强，肿瘤边界变得模糊；④无明显增强型7例，表现为肿瘤内无明显强化。结论：经门静脉低机械指数灰阶超声造影可观察肝实质与肿瘤内造影剂的动态增强过程；为病灶的定性诊断及个性化介入治疗提供有价值的信息。     

实时超声造影在正常移植肝血流动力学研究中的应用

目的:应用实时超声造影定量研究正常移植肝的灌注,并与正常人肝脏灌注特点比较,总结移植肝的血流动力学特征。方法:选取原位肝移植术后临床指标正常的患者(移植组)30例,健康志愿者(健康组)35例,分别对肝脏行实时造影及声学定量分析,比较肝实质的灌注及血流动力学特点。结果:实时超声造影可动态显示肝实质内造影剂的增强过程,其时间-信号强度曲线客观反映造影剂的渡越过程。移植组肝动脉显影时间、门静脉显影时间、肝静脉显影时间、肝动静脉渡越时间、肝动脉-门静脉渡越时间、肝实质开始显影时间、增强峰值时间、峰值强度等与健康组差异均无显著性。结论:本研究初步结果显示移植肝的灌注特征与正常肝脏一致,利用超声造影肝脏灌注显像对移植肝并发症的诊断时,可以考虑采用正常肝脏的指数。     

正常人肝脏灰阶超声造影定量研究

目的 研究正常人肝脏造影剂增强特点及其规律。 方法 对15例正常人肝脏进行SonoVue灰阶超声造影定量分析。 结果 首先肝动脉开始增强呈树枝样，随后门静脉及下腔静脉增强，最后肝静脉增强。肝动脉较门静脉、下腔静脉及肝静脉峰值时间明显提前（P〈0．001）。与后场肝实质比较，前场，中场造影剂开始增强时间和达峰值时间较早，峰值强度较强、渡越时间较长，曲线下面积较大（P〈0．05）。 结论 SonoVue的应用提高了肝内细小血管显示。对于体质量相对较高者可采用提高机械指数和局部放大提高后场造影显示。     

Gray scale contrast enhancement and quantification in different positions of rabbit liver.

OBJECTIVE: The purpose of this study was to evaluate the difference between central and ventral peripheral positions and the difference between left and right lobes in rabbit liver with gray scale contrast enhancement. METHODS: An in vivo model of perfusion was studied with a sulfur hexafluoride contrast agent and low-mechanical-index, real-time, gray scale harmonic imaging. The contrast agent (0.1 mL/kg body weight) was applied respectively in 10 rabbits by intravenous bolus injection. The time-intensity curve was used to obtain flow-related parameters such as time to enhancement (ET), time to peak intensity (PIT), peak signal intensity (PSI), enhancement duration (ED), and area under the curve (AUC). RESULTS: There was a significant difference in parameters of the time-intensity curve between central and peripheral ventral positions of liver parenchyma (P < .05), except for the ED in the left liver. The ET and PIT were earlier, the PSI higher, the ED longer, and the AUC larger in the central position of parenchyma than in the peripheral position. In addition, the ET and PIT were earlier, the PSI higher, the ED longer, and the AUC larger in the right lobe of liver parenchyma than in the left lobe. There was a significant difference in parameters of the time-intensity curve between the left and right lobes of liver parenchyma (P < .05), except for the ET of the peripheral position. CONCLUSIONS: Flow parameters are different between central and ventral peripheral positions and between left and right lobes of hepatic parenchyma.     

Grey-scale contrast enhancement in rabbit liver with SonoVue at different doses

To evaluate the dose of ultrasound (US) contrast agent (UCA) in relation to the contrast-enhancement effect, an in vivo model of perfusion was studied using SonoVue, a second-generation UCA, and low mechanical index (MI) grey-scale harmonic imaging. SonoVue, at eight different doses (0.02, 0.04, 0.06, 0.08, 0.10, 0.12, 0.14 and 0.16 mL/kg BW), was applied in five normal rabbits. Flow-related parameters obtained from time-intensity curves were calculated and plotted over the contrast agent doses, and nonlinear curve fitting was performed. Results showed that, along with an increase of the administrated contrast agent dose, the enhancement duration (ED) and the area under the curve (AUC) increased logarithmically, and the time to enhancement (ET) decreased logarithmically. There was a progressive increase of the peak signal intensity (PSI) following an increase of SonoVue dose only in the dose range of 0.02 up to 0.10 mL/kg body weight (BW) in the portal vein and in the dose range of 0.02 up to 0.12 mL/kg BW in the liver parenchyma. Moreover, a good correlation was observed between the parameters obtained from liver parenchyma and those obtained from the portal vein. The results indicated that SonoVue in conjunction with continuous harmonic low-MI grey-scale imaging has the capability of flow quantification on both vessels and parenchyma. The parameters of time-intensity curve were influenced intensely by different contrast agent doses.     

Time-intensity-based quantification of vascularity with single-level dynamic contrast-enhanced ultrasonography: a pilot animal study.

OBJECTIVE: The purpose of this study was to delineate the hemodynamic features of VX2 tumor and perineoplastic liver parenchyma and to evaluate the potential usefulness of single-level dynamic ultrasonography in the diagnosis of tumors by the analysis of time-intensity curves. METHODS: An in vivo animal model was studied using a low mechanical index in conjunction with single-level dynamic contrast-enhanced ultrasonography. A sulfur hexafluoride contrast agent (SonoVue; Bracco SpA, Milan, Italy) was applied in 8 rabbits by intravenous bolus injection. Data were acquired before and after VX2 tumor induction. Corresponding parameters of the time-intensity curve were measured using wash-in/wash-out curve software. RESULTS: No significant difference was found in the time to enhancement, time to peak intensity, peak signal intensity, and enhancement duration between liver parenchyma before and after VX2 tumor induction (P > .05). The typical enhancement pattern of VX2 tumors was hyperechoic relative to liver parenchyma during the early phase and hypoechoic during the later phase. The curves obtained in carcinomas revealed an early arrival time and time to peak intensity with an irregular and sharp decrease of the intensity signal and a very early return to baseline, presenting a much more rapid wash-in and wash-out of ultrasonographic contrast agents. There was a significant difference in the time to enhancement, time to peak intensity, peak signal intensity, and enhancement duration between the VX2 tumors and perineoplastic liver parenchyma (P < .001). CONCLUSIONS: Single-level dynamic contrast-enhanced ultrasonography with a low mechanical index level could provide real-time and continuous enhanced images and fully delineate the typical enhancement pattern of liver tumors. The analysis of time-intensity curves may provide useful, complementary, and quantitative information. This technique may be useful for the diagnosis of liver tumors, especially those showing an atypical enhancement pattern on biphasic helical computed tomographic scanning.     

Ultrasonographic portography with low mechanical index gray-scale imaging in hepatic VX2 tumor

To evaluate the characteristics of portal blood supply of hepatic tumors by ultrasonographic portography (USP), an in vivo model was studied using SonoVue, a second-generation ultrasound contrast agent (UCA) and low mechanical index (MI), gray-scale harmonic imaging. SonoVue (0.05 mL) was administrated through catheter placed into the main trunk of portal vein at laparotomy, followed by a 0.5 mL saline flush, in 12 rabbits with hepatic VX2 tumor, implanted by VX2 tumor tissue cubes of approximately 1 mm3 from carrier rabbit. Results showed that low MI gray-scale imaging delineated clearly the dynamic enhancement of tumors and liver parenchyma. Among 22 tumors, seven tumors were diffusely increased, with the intensity of enhancement weaker than that of the surrounding liver parenchyma. The UCA was washed out earlier from tumors than from surrounding liver parenchyma. Three tumors showed the branches of portal vein. Five tumors showed peripheral contrast enhancement and a central coarse unenhanced hypoechoic area. Seven tumors displayed no actual enhancement. All lesions (100% [22 of 22]) were depicted clearly in the whole duration of enhancement, especially in the early and late phase, regardless of enhancement pattern, and portal blood flow was manifested in 15 of 22 (68%) tumors, by USP. The enhancement pattern of the tumors corresponded to the pathologic findings. The results indicated that ultrasonographic portography, combined with low MI levels and second-generation UCA, is a sensitive and safe method to study portal blood supply for liver cancer. It may contribute to improvement of the detectability and diagnostic ability and assist the choice of a therapeutic strategy for treatment of liver cancer. However, applicability of the method to human may be problematic because of high invasiveness and great difficulty in administering contrast medium.