Advances in 3D echocardiography for mitral valve

The advent of real-time (RT) 3D transesophageal echocardiography (TEE) in 2007 has enhanced our understanding of the location and extent of the pathology of the native, as well as prosthetic, mitral valve (MV), particularly for MV prolapse and the anatomy of perivalvular dehiscence with prosthetic MV. MV quantification programs provide precise assessment of many quantitative MV parameters allowing 3D echocardiography to determine and quantify the geometry of mitral apparatus, including mitral annulus and periannular region, leaflet volume and anatomy, tethering distances, and tenting volumes. The detailed, accurate and optimal RT spatial visualization of the MV with 3D TEE gives greater confidence to the echocardiographer, interventionalist and the surgeon alike, facilitating medical and surgical treatment decisions. This article highlights recent advances in RT 3D TEE and transthoracic echocardiography echocardiographic imaging of the MV.     

Personalized mitral valve closure computation and uncertainty analysis from 3D echocardiography

Intervention planning is essential for successful Mitral Valve (MV) repair procedures. Finite-element models (FEM) of the MV could be used to achieve this goal, but the translation to the clinical domain is challenging. Many input parameters for the FEM models, such as tissue properties, are not known. In addition, only simplified MV geometry models can be extracted from non-invasive modalities such as echocardiography imaging, lacking major anatomical details such as the complex chordae topology. A traditional approach for FEM computation is to use a simplified model (also known as parachute model) of the chordae topology, which connects the papillary muscle tips to the free-edges and select basal points. Building on the existing parachute model a new and comprehensive MV model was developed that utilizes a novel chordae representation capable of approximating regional connectivity. In addition, a fully automated personalization approach was developed for the chordae rest length, removing the need for tedious manual parameter selection. Based on the MV model extracted during mid-diastole (open MV) the MV geometric configuration at peak systole (closed MV) was computed according to the FEM model. In this work the focus was placed on validating MV closure computation. The method is evaluated on ten in vitro ovine cases, where in addition to echocardiography imaging, high-resolution μCT imaging is available for accurate validation.     

经食管超声心动图在二尖瓣修复术中的应用

目的　探讨经食管超声心动图 (TEE)在二尖瓣反流性病变修复术中的指导作用。方法　对 19例二尖瓣反流 (MR)患者 ,体外循环 (CPB)前及修复术后 ,应用TEE评价二尖瓣结构的异常。在相同的仪器条件和相近的血流动力学状态下 ,以实时目测法估测MR。结果　CPB前TEE检查纠正术前诊断 1例。CPB前MR(3 .4± 0 .5 )级 ,修复后残余MR(1.2± 1.0 )级 (P <0 .0 0 0 1)。 2例因残余MR 3级 ,再次转机行二尖瓣替换术。17例修复术患者出院前经胸超声心动图 (TTE)示残余MR与术中TEE残余反流量无显著性差异 [(0 .9± 0 .7)级vs (0 .9± 0 .8)级 ,P >0 .0 5 ]。后叶病变修复效果明显优于前叶。结论　TEE在二尖瓣修复术前后提供了较为可靠的二尖瓣结构和血流的信息 ,以指导手术治疗。实时目测法半定量评估MR是术中可靠且实用的方法     

实时三维超声心动图在二尖瓣病变中的应用

二尖瓣特殊的解剖结构、功能特点使其成为研究热点。本文就实时三维超声心动图在二尖瓣狭窄、二尖瓣瓣叶脱垂、二尖瓣关闭不全及二尖瓣手术中的应用进行综述。     

三维经食管超声心动图评估非瓣膜性心房颤动患者左心耳封堵术后二尖瓣装置形态

目的:探讨经食管3D超声心动图用于左心耳封堵术后二尖瓣装置形态改变情况的评估价值,旨在为术前封堵器选择提供更多参考。方法：回顾性纳入2017年1月-2022年12月于我院行左心耳封堵术治疗房颤患者共35例,分别于手术前后行经食管2D/3D超声心动图检查,分析二尖瓣装置相关定量参数变化情况,进一步评价术后封堵器压缩比与二尖瓣装置相关定量参数的相关性。结果：术后二尖瓣瓣环瓣环前外侧至后内侧、三维瓣环周长、二维瓣环面积、三维瓣环面积、穹隆容积、穹隆下投影面积及瓣叶联合处直径均显著小于术前(P<0.05);术后前后径/前外侧至后内侧径显著大于术前(P<0.05);瓣叶穹隆容积与术后封堵器压缩比呈显著正相关(P<0.05);术后封堵器压缩比与二尖瓣装置其他相关定量参数间无明显相关性(P>0.05)。结论：经食管3D超声心动图可准确用于左心耳封堵术后二尖瓣装置形态改变评估,同时二尖瓣装置术前穹隆容积及封堵器压缩比均可影响封堵器。     

实时三维超声心动图诊断二尖瓣叶裂

目的 探讨实时三维超声(RT-3DE)在二尖瓣叶裂(MVC)诊断中的价值。 方法 对17例经二维超声心动图诊断MVC的患者在左心室长轴切面和二尖瓣短轴切面实施RT-3DE全容积显像,在三个方位(冠状位、矢状位、水平位)、六个方向对图像进行剖析观察,对二尖瓣瓣叶裂进行定位诊断,测量裂口宽度及长度,观察裂口与周围结构的空间位置关系。 结果 RT-3DE全容积图像可以清晰显示瓣叶裂的位置、宽度、长度及裂口宽度随心动周期的变化及其与周围腱索、主动脉瓣的空间位置关系。 结论 RT-3DE能为超声医生对MVC的诊断提供更明确的诊断依据,为心脏外科医生的手术方式的选择提供更全面的参考信息。     

经食管三维超声心动图评价人工二尖瓣瓣周反流

目的 探讨经食管三维超声心动图评价人工二尖瓣术后瓣周反流的可行性、准确性.方法 2007年12月至2011年8月本心脏中心因二尖瓣置换术后瓣周反流行再次心脏手术的病例24例,男17例.女7例,年龄30~65岁,平均(48±9)岁,24例均术前行经胸二维超声检查,ll例行经食管二维超声检查.9例行经食管三维超声检查.以外科术中所见为金标准,分别对比经胸二维超声、经食管二维超声、经食管三维超声评价瓣周反流存在与否、位置、程度及病因的准确性.结果 经胸二维超声、经食管二维超声、经食管三维超声评价瓣周反流存在与否准确性分别为87.5%(21/24),100%(11/11),100%(9/9);判断瓣周反流位置准确性:经胸二维超声62.5%(15/24),经食管二维超声81.8%(9/11),经食管三维超声100%(9/9);判断反流程度准确性:经胸二维超声70.8%(17/24),经食管二维超声72.7%(8/11),经食管三维超声100%(9/9);判断病因准确性:经胸二维超声54.2%(13/24),经食管二维超声63.6%(7/11),经食管三维超声88.8%(8/9).结论 经食管三维超声心动图能实时提供人工二尖瓣瓣周立体信息,在评价二尖瓣置换术后瓣周反流存在与否、位置、程度、病因中起到重要作用,具有更高的准确性.     

实时三维经食管超声心动图对二尖瓣脱垂的诊断价值

目的比较实时三维经食管超声心动图（RT-3D-TEE）与二维经胸超声心动图（2D-TTE）、二维经食管超声心动图（2D-TEE）对二尖瓣脱垂的诊断价值。 方法回顾性分析2018年1月至2020年12月于武汉亚洲心脏病医院因二尖瓣脱垂行外科手术治疗,并在术前进行了2D-TTE、2D-TEE和RT-3D-TEE的患者共370例。以术中诊断为“金标准”,计算3种检查方法对二尖瓣脱垂瓣叶定位、腱索及赘生物形成的诊断效能,对3种检查方法的敏感度、特异度及准确性进行比较,并采用Kappa检验分别对3种方法诊断结果与术中诊断结果的一致性进行分析。 结果370例患者中,术前2D-TTE诊断出二尖瓣脱垂361例,检出率97.5%;术前2D-TEE诊断368例,检出率99.4%;而RT-3D-TEE检出率达100%。RT-3D-TEE对瓣叶脱垂的分区定位的敏感度、特异度和准确性均高于2D-TTE（P均＜0.05）,对腱索断裂诊断的敏感度和准确性亦高于2D-TTE,差异有统计学意义（P均＜0.05）,且RT-3D-TEE对脱垂分区定位的准确性高于2D-TEE（P均＜0.05）。一致性分析结果显示,RT-3D-TEE各项指标与术中诊断均具有良好的一致性（Kappa值均＞0.75,P均＜0.05）。 结论RT-3D-TEE较2D-TTE、2D-TEE对二尖瓣脱垂区域的定位及相关病变的识别更准确,可为手术医师提供更为直观、精准的影像信息,帮助制定个性化治疗方案。     

实时三维超声心动图在评价二尖瓣膜瘤中的应用

目的 评价实时三维超声心动图（real-time three-dimensional echocardiography，RT-3DE）诊断二尖瓣膜瘤（mitral valve aneurysm，MVA）的应用价值。方法采用Philips iE33，对经常规二维超声心动图诊断MVA的8例患者，进行实时三维超声和立体图像处理，观察二尖瓣膜瘤的空间结构特征，并与手术结果对照。结果8例患者均获得二尖瓣膜瘤清晰的三维图像，病变均位于二尖瓣前叶，7例联合存在主动脉瓣反流。与手术结果对比，实时三维超声准确显示病变情况。结论联合实时二维和三维超声心动图能全面准确诊断二尖瓣膜瘤。     

Three-dimensional echocardiography in congenital malformations of the mitral valve.

Three-dimensional echocardiography has proved to be valuable in congenital heart disease by enhancing the evaluation of morphologic abnormalities and increasing the understanding of complex relationships. This study was undertaken to determine how 3-dimensional echocardiography could be best used to study some of the congenital malformations of the mitral valve such as mitral arcade, double orifice mitral valve, accessory mitral tissue, cleft mitral valve, and unicuspid mitral valve. Five patients were studied. Three-dimensional echocardiography was found to be helpful in defining spatial location and extent of deformities.     

Quantification of mitral valve stenosis by three-dimensional transesophageal echocardiography

The aim of this study was the evaluation of the diagnostic potentials of transesophageal 3D-echocardiography in the determination of mitral valve stenosis. 54 patients were investigated by transthoracic and multiplane transesophageal echocardiography. In 41 patients cardiac catheterization was performed. 3D-echocardiographic data acquisition was performed by automatic transducer rotation at 2° increments over a span of 180°. The transesophageal probe was linked to an ultrasound unit and to a 3D-workstation capable of ECG- and respiration gated data acquisition, postprocessing and 2D/ 3D image reconstruction. The mitral valve was visualized in sequential cross-sectional planes out of the 3D data set. The spatial position of the planes was indicated in a reference image. In the cross-sectional plane with the narrowest part of the leaflets the orifice area was measured by planimetry. For topographic information a 3D view down from the top of the left atrium was reconstructed. Measurements were compared to conventional transthoracic planimetry, to Doppler-echocardiographic pressure half time and to invasive data. The mean difference to transthoracic planimetry, pressure half time and to invasive measurements were 0.3 ± 0.1 cm², 0.2 ± 0.1 cm² and 0.1 ± 0.1 cm², respectively. Remarkable differences between the 3D- echocardiographic and the 2D- or Doppler- echocardiographic methods were observed in patients with severe calcification or aortic regurgitation. In 22% of the patients the 3D data set was not of diagnostic quality. New diagnostic information from a 3D view of the mitral valve could be obtained in 69% of the patients. Thus, although image quality is limited, 3D- echocardiography provides new topographic information in mitral valve stenosis. It allows the use of a new quantitative method, by which image plane positioning errors and flow-dependent calculation is avoided.     

Transcatheter valve-in-valve implantation for degenerated mitral valve bioprosthesis under 3D echocardiographic guidance

Transcatheter mitral valve-in-valve replacement is increasingly being performed as operator and center experience in transcatheter valve replacement technology and techniques have accrued. Complications, such as valve embolization and paravalvular regurgitation, still occur and relate to valve deployment. The use of novel imaging techniques, such as 3D echocardiography, allows for better differentiation of cardiac structures and appropriate positioning of the transcatheter valve using well-visualized anatomical landmarks. Here the authors describe in images and video the use of 3D echocardiography for deployment of a mitral valve-in-valve.     

Feasibility of measurements of valve dimensions in en-face-3D transesophageal echocardiography

Newest 3D software allows measurements directly in the en-face-3D TEE mode. Aim of the study was to ascertain whether measurements performed in the en-face-3D TEE mode are comparable with conventional measurement methods based on 2D TEE and 3D using the multiple plane reconstruction mode with the Qlab^® software. En-face-3D TEE is used more frequently in daily clinical routine during cardiac operations. So far measurements could only be done based on 2D images or with the use of multi planar reconstruction mode with additional software. Measurement directly in the 3D image (en-face-3D TEE) would make measurements faster and easier to use in clinical practice. After approval by the local ethic committee and written informed consent from the patients additionally to a comprehensive perioperative 2D TEE examination a real time (RT) 3D zoom- dataset was recorded. Routine measurements of the length of anterior and posterior mitral valve leaflets as well as mitral valve and aortic valve areas were performed in en-face-3D TEE, multiplanar reconstruction mode using Qlab^®-software (Philips, Netherlands) and 2D TEE standard views. Twenty nine patients with a mean age of 67 years undergoing elective cardiac surgery/interventions were enrolled in this study. Direct measurements in en-face-3D TEE mode lead to non significant underestimation of all parameters as compared to Qlab^® and 2D TEE measurements. Measurements in en-face-3D TEE are feasible but lead to non significant underestimation compared to measurements performed with Qlab^® or in 2D TEE views.     

超声心动图对二尖瓣狭窄瓣膜置换术后血流动力学改变的研究

目的 应用彩色多普勒超声心动图了解二尖瓣狭窄患者接受二尖瓣置换术(MVR)前、后血流动力学改变情况。方法 回顾性分析37例二尖瓣狭窄患者接受MVR前、后左房内径、三尖瓣反流速率、肺动脉收缩压(PAPS)及左室射血分数改变情况，并进行PAPS与二尖瓣跨瓣压差(MV△P)间相关性分析。结果 所有患者术后均健康存活，平均随访15．8个月。随访结果：MVR后左房内径、三尖瓣反流速度及PAPS均较术前显著下降，而左室射血分数则较术前显著上升。PAPS与MV△P间呈显著正相关，且随PAPS升高，PAPS与MV△P差值亦显著升高。结论MVR能有效地改善二尖瓣狭窄血流动力学，PAPS与MV△P呈正相关，重度肺动脉高压患者肺循环内存在二级狭窄。     

小儿先天性二尖瓣畸形的外科治疗进展

先天性二尖瓣畸形是最常见的小儿瓣膜畸形,多数需要手术干预,二尖瓣成形术是外科治疗二尖瓣畸形的首选方法,其成形效果持久,术后并发症少,死亡率低。本文对小儿先天性二尖瓣畸形外科治疗的各种手术方法进行综述。