腔内影像技术指导支架内血栓预防及机制评价的研究进展

冠状动脉支架内血栓是冠状动脉支架置入术后并发症之一,起病急,病死率高。近年来,以血管内超声及光学相干断层成像为代表的腔内影像技术发展迅速,广泛应用于临床。本文综述了腔内影像技术对支架内血栓预防及机制评价方面的研究进展。     

血管内超声在脑血管疾病诊治中的研究进展

正血管内超声(intravascular ultrasound,IVUS)是基于导管的超声装置,该技术借助介入放射学方法将超声导管直接置入血管中,可显示血管内影像,检测血管壁性质等,已在心脏与外周血管疾病领域显示出其优势~[1-2],但在脑血管疾病的诊疗领域尚属探索阶段。DSA被认为是脑血管疾病诊断的"金标准",但传统的依靠动脉直径狭窄率来评价颅内外血     

不稳定斑块诊断的影像学进展

冠心病仍是人类健康的主要杀手。不稳定斑块的识别是心血管研究的主要目的。血管内影像技术的进展已经能够根据斑块的特点鉴别高危、不稳定的斑块。覆盖于脂质核心的薄的纤维帽促进高分辨率的影像学技术的发展 ,包括 :血管内超声、光谱一致性断层摄影术和血管内磁共振。纤维帽下的富于胆固醇的脂质核心可通过血管镜探测的反射在斑块表面的颜色改变来鉴别 ;亦可通过其本身单一的能量吸收来鉴别 ,由此引起冠脉内光谱镜检查 (包括 :近红外线的分光谱学检查、拉曼光谱学检查 )的发展。最后 ,由斑块炎症引起的温度的不均匀性促进了冠脉内温度测量法的发展。本综述主要是总结目前识别不稳定斑块的侵入性技术的发展和比较各自的优缺点     

光学相干断层显像在肺动脉高压中的应用进展

肺动脉高压是是多种临床情况导致的血流动力学和病理生理学变化。肺动脉的直接影像学评价肺血管造影和肺组织活检的应用仍受到许多限制。近年来,血管内影像检查技术不断发展,血管内超声(IVUS)和光学相干断层显像(OCT)为评估血管结构提供了实时、在体、定量和定性检查的可能。本文旨在对目前使用OCT评估肺动脉的研究进行总结,对OCT在肺动脉高压应用中的进展进行综述。     

血管内超声在冠状动脉粥样硬化性心脏病诊治中应用

血管内超声(intravascular ultrasound,IVUS)显像技术是将微型化的超声探头通过导管技术送入血管腔内,实时显示血管横截面图像,可观察血管腔和血管壁动脉粥样硬化病变的形态,并可根据病变回声特性判断病变的性质,精确测定血管腔、血管的大小及病变狭窄程度,可用于指导介入治疗。1971年Bom首先发明超声导管,用于心腔和瓣膜成像。20世纪80年代末开始应用于人体冠状动脉,是第一个     

光学相干断层成像技术在冠状动脉内应用的研究进展

光学相干断层成像技术(OCT)是目前分辨率最高的腔内影像技术,在评估急性冠状动脉(冠脉)综合征患者罪犯病变斑块的特征、易损斑块、钙化斑块、支架内膜覆盖情况,以及支架内再狭窄、指导冠脉介入治疗和用药等方面有独特的优势。现就OCT的研究进展进行综述。     

血管内超声评估颈动脉粥样硬化研究进展

<正>血管内超声(IVUS)能清晰显示血管横断面,精确测量血管腔内径和截面积,并且可发现早期粥样硬化斑块,根据斑块声学特征进行组织学分型,指导和评定血管内介入治疗[1]。临床应用经验表明,IVUS成为冠状动脉疾病临床诊断和介入治疗中的"金标准"[2]。1 IVUS成像原理及颈动脉特点目前临床上应用的IVUS成像设备种类较多,主要组成成分包括:超声导管、超声探头、导管步进器和图像处理系     

超声心动图在心血管病介入治疗中的应用

近年来,随着心血管病介入与微创治疗应用范围的拓展,新的治疗术式不断创新,各种超声心动图技术包括常规经胸超声(TTE)、经食管超声(TEE)、心腔内超声(ICE)、血管内超声(IVUS)、超声声学造影(MCE)以及三维超声心动图等,在心血管病介入     

易损斑块的血管内超声研究进展

罪犯血管病变冠状动脉粥样斑块破裂(糜烂)和伴随的血栓形成被认为是急性冠脉综合征的主要启动机制。血管内超声是当前唯一临床上可利用的能够提供血管壁实时截面图像的技术,研究能够成像斑块形态和活性(炎症)的血管内技术是心脏病学界最近非常活跃的课题,虽然其它血管内成像技术的发展取得了重要进步,血管内超声仍然是介入心脏病专家可用的、应用最广泛的技术。     

血管内超声在冠状动脉介入治疗中的应用

<正>血管内超声(IVUS)是无创性的超声技术和有创性的导管技术相结合的,应用于临床以诊断血管病变的一种新的诊断手段,在冠心病的诊疗中具有重要指导价值。由于IVUS能够显示血管的横断面图像,从而准确提供血管的诸多信息〔1〕,可以多方面弥补血管造影的不足,准确观察血管腔的形态、管壁之间的关系,测量血管狭窄程度和判断斑块的性质,从而更好地指导临床治疗〔2〕。现将IVUS在心血管介入治疗中的应用优势     

In-vitro validation, with histology, of intravascular ultrasound in renal arteries

OBJECTIVE: To investigate the feasibility of using intravascular ultrasound to characterize normal and diseased renal arteries. MATERIALS AND METHODS: Forty-four renal artery specimens from 21 humans, removed at autopsy, were studied with intravascular ultrasound in vitro. From each vascular specimen, two to four sets of corresponding intravascular ultrasound images and histologic sections were subjected to qualitative analysis. The renal arterial wall was considered normal by intravascular ultrasound when the wall thickness (intima and media) was 0.5 mm or less. On intravascular ultrasound imaging, a distinction was made between bright lesions with or without peripheral shadowing (i.e. calcification). Histological sections were examined and fibromuscular lesions were scored with or without calcifications. Quantitative analysis of a multitude of intravascular ultrasound cross-sections (interval 5 mm) included assessment of the lumen area, vessel area, plaque area and percentage area obstructed. The target site (smallest lumen area) was compared with a reference site (largest lumen area before the first major side branch). RESULTS: Of the 130 corresponding intravascular ultrasound images and histologic sections analysed, 55 were normal and 75 presented a bright lesion on ultrasound; in 31 lesions, peripheral shadowing was involved. The sensitivity of the intravascular ultrasound in detecting calcifications was 87%, and the specificity was 89%. Lumen area reduction at the target site was associated with vessel and plaque area enlargement in eight specimens, with plaque area enlargement in 12 specimens and with a vessel area reduction in 21 specimens. CONCLUSIONS: Intravascular ultrasound is a reliable technique for distinguishing renal arteries with or without a lesion. Both plaque development and local vessel narrowing may result in renal artery stenosis.     

自制新型血管内超声双腔微导管引导下行慢性完全闭塞病变介入治疗

处理入口不明的慢性完全闭塞病变(CTO)可借助血管内超声,但反复交换微导管和超声导管可能增加操作相关并发症。解放军白求恩国际和平医院自主研发的新型血管内超声双腔微导管,由血管内超声导管以及与其并联为一体的治疗微导管构成,超声导管和工作导丝同步进入病变部位,相当于在血管内超声实时探查下进行直接定位操作,有助于正确把握穿刺方向,为介入医师进行慢性闭塞病变的治疗增添了新工具。在此基础上,本文通过结合1例应用此新型血管内超声双腔微导管成功治疗入口闭塞的CTO病变经验,为读者提供更为直观的认识。     

Comparison of intravascular ultrasound, external ultrasound and digital angiography for evaluation of peripheral artery dimensions and morphology

Validation of catheter-based intravascular ultrasound imaging has been based on comparisons with histology and digital angiography, each of which may have limitations in the assessment of arterial size and morphology. External, high-frequency ultrasound can accurately determine vessel dimensions and morphology and because, like ultravascular ultrasound, it also provides cross-sectional arterial ultrasound images, it may be a more appropriate technique for the in vivo comparison of arterial dimensions and morphology determined by intravascular ultrasound. Thus, intravascular ultrasound, external 2-dimensional ultrasound, Doppler color-flow imaging and digital angiography were compared for assessment of arterial dimensions and wall morphology at 29 femoral artery sites in 15 patients. Intravascular ultrasound and the other 3 imaging modalities correlated well in determination of lumen diameter (2-dimensional, r = 0.98, standard error of the estimate [SEE] = 0.14; Doppler color flow, r = 0.91, SEE = 1.11; angiography, r = 0.95, SEE = 0.91) and cross-sectional area (2-dimensional, r = 0.97, SEE = 0.04; Doppler color flow, r = 0.92, SEE = 0.14; angiography, r = 0.96, SEE = 0.08). However, lumen size measured by Doppler color flow was consistently smaller than that measured by the other 3 imaging modalities. Intravascular ultrasound detected arterial plaque at 15 sites, 5 of which were hypoechoic (soft) and 10 hyperechoic with distal shadowing (hard). Plaque was identified at 12 of 15 sites by Z-dimensional imaging (p = 0.30 vs intravascular ultrasound), but at only 6 of 15 sites by angiography (p = 0.003 vs intravascular ultrasound), only 1 of which was thought to be calcified plaque.(ABSTRACT TRUNCATED AT 250 WORDS)     

Intravascular ultrasound: potential tool to assess coronary anastomosis quality

Coronary angiography and Doppler flow measurements are most commonly used to assess the patency of anastomoses in the operating theater. Intravascular ultrasound might be another means of monitoring the surgical procedure during coronary artery bypass. Five sheep underwent off-pump bypass of the left anterior descending coronary artery using the left internal mammary artery. The running suture was evaluated by intraoperative fluoroscopy and a coronary intravascular ultrasound probe inserted into the target artery proximal to the anastomosis. Macroscopic examination of the anastomosis was performed to validate the angiographic and intravascular ultrasound images. The diameter, cross-sectional area, and compliance of each anastomosis were calculated in systole and diastole. All anastomoses were patent without signs of stenosis. In one case, intravascular ultrasound showed an intimal flap, which was confirmed by macroscopic examination. The mean major anastomotic diameter was 4.5 +/- 0.5 mm on angiography and 4.0 +/- 0.5 mm on intravascular ultrasound. From the ultrasound data, the mean cross-sectional anastomotic area was calculated as 6.21 +/- 0.1 mm(2) in systole and 5.49 +/- 0.1 mm(2) in diastole, and these data were used to calculate the cross-sectional anastomosis compliance. Coronary intravascular ultrasound can visualize intima-to-intima apposition and provide reliable calculations of anastomosis compliance.     

In vitro analysis of coronary atheromatous lesions by intravascular ultrasound; reproducibility and histological correlation of lesion morphology.

AIM: To determine the reproducibility and histological correlation of qualitative intravascular ultrasound imaging of atheromatous coronary arteries using the recently proposed European Society of Cardiology classification of plaque composition in conditions approximating the clinical setting. METHODS: Atheromatous lesions (n=21), identified from 30 post-mortem human coronary arteries, were imaged using intravascular ultrasound in a pulsatile flow system which simulates coronary flow. Fifty sites (21 x minimum lumen area and 29 x distal reference sites) were selected independently by two observers from continuous video recordings. Atheromatous plaque was classified as echodense, echolucent, heterogeneous or calcified by each observer and by one observer on separate occasions. Arterial specimens were histologically sectioned at these sites and similarly analysed by a third observer blinded to the intravascular ultrasound appearances. RESULTS: Overall inter- and intra-observer reproducibility for plaque-type (Kappa 0.87[0.80-0.94] and 0.89[0. 85-0.93 respectively]) and focal calcification (0.78[0.74-0.82] and 0.88[0.84-0.92]) was high. Differences in site selection significantly influenced reproducibility particularly at reference sites. Agreement for overall plaque type between intravascular ultrasound and histology occurred in 89% of sites (Kappa 0.73[0.69-0. 77]). Specificity and positive predictive values for individual plaque types were greater than 90%. CONCLUSION: Using modern intravascular ultrasound technology in an in vitro system which approximates the clinical setting the proposed ESC classification of plaque composition by intravascular ultrasound is reproducible and correlates well with histology. It should therefore perform reliably in diagnostic intravascular ultrasound examinations and in the guidance of percutaneous coronary interventions.     

Virtual histology: a window to the heart of atherosclerosis

Intravascular ultrasound has done much to improve our understanding of atherosclerosis and the impact of percutaneous intervention on the coronary artery. However, subjectivity in interpreting the acoustic reflection of the ultrasound signal has spawned the development of other progressive technologies. Virtual histology intravascular ultrasound (VHIVUS) utilises the ultrasound backscatter signal in order to colour code plaque into four pre-specified subtypes based on their histological composition. We review the background behind traditional grey scale intravascular ultrasound (IVUS) and examine the current evidence for VHIVUS and its potential for use in clinical interventional practice.     

Interventional applications of intravascular ultrasound imaging: initial experience and future perspectives

Intravascular ultrasound imaging offers the potential to provide more detailed information about vessel and lesion morphology and physiology than is currently available from angiography. The greatest impact of intravascular ultrasound upon clinical decisions may be in the area of cardiac and vascular interventions. To evaluate the utility of intravascular ultrasound, we prospectively studied 45 patients, 11 of whom underwent interventional procedures. Intravascular ultrasound imaging was performed before and after interventions using a 20 MHz, mechanically rotating transducer on either 6.5 Fr or 8.0 Fr catheter systems. Interventions included seven peripheral vessel balloon angioplasties (Femoral artery-two, Renal artery-two, Arteriovenous fistula-two, Aortic coarctation-one), two Femoral artery rotational atherectomies, and two balloon valvuloplasties (Pulmonic valve-1, Mitral valve-1). Intravascular ultrasound and digital angiography provided similar information about vessel size. However, morphological information about the vessel wall, plaque composition, plaque topography, luminal thrombus, and vessel dissections was better appreciated by intravascular ultrasound. Intravascular ultrasound was determined to have provided unique and clinically useful information in 10/11 (91%) interventions. These preliminary data illustrate the potential value of intravascular ultrasound for the evaluation of the vascular system and in particular its value in interventional procedures.     

Anatomic and functional assessment of stenosis severity with intravascular ultrasound imaging in vitro

An in vitro study was performed to evaluate the accuracy of intravascular ultrasound imaging compared with roentgenography for determining the cross-sectional area of a lumen; and to determine if the functional significance of an irregular stenosis is predicted more accurately by intravascular ultrasound than roentgenography. Varying degrees of stenosis were made in 17 rubber tubings by adjusting a plastic constrictor. The cross-sectional areas at the normal and the stenotic segments were determined by intravascular ultrasound, roentgenography, and then measured directly from an acrylamide gel cast of the lumen. To evaluate the functional significance of a stenosis, the pressure drop across the stenosis was measured using a fluid pumping circuit. The actual pressure drop was then compared with the predicted pressure drop derived from hydrodynamic equations using cross-sectional areas obtained by intravascular ultrasound or roentgenography. There was an excellent correlation between the cross-sectional areas at the tightest stenosis measured by intravascular ultrasound compared with the area from the acrylamide cast (7.2 +/- 2.6 v 6.6 +/- 2.4 mm 2, mean +/- SD, r = .93). Measurements of cross-sectional area from the roentgenograms (10.9 +/- 3.9 mm 2) also provided a relatively good correlation with those from the acrylamide casts (r = .84); however, the roentgenograms consistently overestimated the cross-sectional area of the stenosis. The mean values of the actual pressure drop and the predicted pressure drop by intravascular ultrasound and roentgenograms were 15.7 +/- 13.5, 11.3 +/- 11.9, and 4.3 +/- 4.5 mmHg, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)     

Clinical evaluation of acute and chronic pulmonary thromboembolism using intravascular ultrasound and angioscopy

Pulmonary artery thrombi and parietal lesions were observed in 13 patients (mean age 58 +/- 18 years) with acute pulmonary thromboembolism (n = 4) and chronic pulmonary thromboembolism (n = 9) using intravascular ultrasound and angioscopy at the time of right heart catheterization. Patients with acute pulmonary thromboembolism without underlying disease mainly had non-echogenic intraluminal mass, and good pulsatile vessel without intimal thickening. Angioscopy directly showed red thrombi with white fibrin coating, and no parietal lesions. Patients with chronic pulmonary thromboembolism could be classified into 3 groups: 1) Poor extensibility of the vessel wall and intimal thickening with non-echogenic thrombi on intravascular ultrasound, and relatively fresh parietal thrombi consisting of a mixture of red blood cell and fibrin, and spider web-like fibrin net on angioscopy (6 patients). 2) Crescent parietal thrombi and wall irregularity on intravascular ultrasound, and probably organized thrombi with a mixture of red and white surface on angioscopy (one patient). 3) Marked and echogenic intimal thickening and poor extensibility on intravascular ultrasound, and intimal surface irregularities and yellowish changes on angioscopy (one patient). All patients suffering acute deterioration in the chronic phase belonged to groups 1) or 2). Intravascular ultrasound and angioscopy are useful for characterizing the thrombi and related pulmonary artery lesions in patients with pulmonary thromboembolism. The pulmonary artery intima and thrombus differ between acute and chronic pulmonary thromboembolism.     

Optimized ultrasound imaging catheters for use in the vascular system

Clinical experience with 6 and 9 Fr ultrasound imaging catheters (UICs) reveals that several transducer and catheter tip varieties are needed for optimum imaging of diseased intravascular sites. Our UIC design has combined established catheter design and very high frequency ultrasound imaging technology to create a versatile, user configured system for intravascular ultrasound imaging. Optimum use requires proper strategic selection of transducer and catheter sizes, frequencies of operation, and interventional accessories.