Abstract：
Greater interest in imaging the superior vena cava (SVC) in recent years has arisen because of increased focus on disorders of the right heart; the growing use of transvenous access lines, dialysis catheters, and device leads; and the emergence of right ventricular mechanical circulatory support systems via the transcatheter approach. As a low-pressure venous conduit in the right upper mediastinum, the SVC is prone to compression by various pathologic processes, to invasion by malignancies originating in nearby structures, and to complications arising from intraluminal device leads and indwelling catheters. Computed tomography and magnetic resonance venography are the modalities of choice for structural imaging of the SVC. Ultrasound allows a reasonable, yet less detailed anatomic assessment of this venous conduit. Spectral and color Doppler imaging by ultrasound are the most valuable noninvasive tools for the interrogation of SVC blood flow, a marker of the filling pattern of the right heart. Analysis of the velocity, duration, and direction of the Doppler waveforms and their phasic response to respiration makes it possible to distinguish normal from abnormal flow patterns and offers diagnostic insights into disorders that affect right heart function. The aims of this review are to demonstrate the added value SVC imaging provides during transthoracic and transesophageal echocardiographic studies, to outline its usefulness for the detection and evaluation of structural abnormalities, and to detail the role of spectral Doppler imaging in aiding the diagnosis of various disorders that affect the right heart.
摘要：
近年来，由于对右心疾病的关注日益增加，人们对上腔静脉（SVC）的成像产生了更大的兴趣，越来越多地使用经静脉通路，透析导管和装置导线，以及经导管入路右心室机械循环支持系统的出现。作为右上纵隔的低压静脉导管，SVC容易受到各种病理过程的压迫，来自附近结构的恶性肿瘤侵入，以及由腔内装置导线和留置导管引起的并发症。计算机断层扫描和磁共振静脉造影是SVC结构成像的首选方式。超声波允许合理的，但对该静脉导管的解剖评估较少。超声的频谱和彩色多普勒成像是最有价值的非侵入性工具，用于询问SVC血流，右心填充模式的标记。分析速度，多普勒波形的持续时间和方向及其对呼吸的阶段性反应允许区分正常和异常血流模式，并提供对影响右心功能的疾病的诊断见解。这篇综述的目的是证明SVC成像在经胸和经食道超声心动图研究中提供的附加价值。概述其对检测和评估结构异常的有用性，并详细介绍频谱多普勒成像在帮助诊断影响右心的各种疾病中的作用。
