D'Andrea Antonello, Radmilovic Juri, Mele Donato, Di Giannuario Giovanna, Rizzo Massimiliano, Campana Marco, Riegler Lucia, Gimelli Alessia, Khoury Georgette, Strano Stefano, Moreo Antonella
U.O.C. Cardiologia/UTIC/Emodinamica, P.O. Umberto I, Nocera Inferiore (ASL Salerno), Università "Luigi Vanvitelli" della Campania.
Dipartimento di Scienze Cardio-Toraco-Vascolari e Sanità Pubblica, Università degli Studi, Padova.
G Ital Cardiol (Rome). 2021 Dec;22(12):988-999. doi: 10.1714/3698.36878.
Non-invasive Doppler ultrasonographic study of cerebral arteries (transcranial Doppler, TCD) has been extensively applied on both outpatient and inpatient settings. It is performed placing a low-frequency (≤2 MHz) transducer on the scalp of the patient over specific acoustic windows, in order to visualize the intracranial arterial vessels and to evaluate the cerebral blood flow velocity and its alteration in many different conditions. Nowadays a valid indication for TCD in the outpatient setting is the research of right-to-left shunting, responsible for the so-called "paradoxical embolism", most often due to patency of foramen ovale, which is responsible for the majority of cryptogenic strokes occurring in patients younger than 55 years. TCD also allows to classify the grade of severity of such shunts using the so-called "microembolic signal grading score". Therefore, TCD is an essential cardiological exam for the detection of patent foramen ovale, assuming an important role as a first-level examination to guide the subsequent diagnostic-therapeutic management. In addition, TCD has found many useful applications in neurocritical care practice. It is useful for the identification of intracranial vascular stenosis and for the assessment of critical conditions including vasospasm in subarachnoid hemorrhage, traumatic brain injury and brain stem death. It is also used to evaluate cerebral hemodynamic changes after stroke, to investigate cerebral pressure autoregulation, and for the clinical evaluation of cerebral vasomotor reactivity.
脑动脉的无创多普勒超声检查（经颅多普勒，TCD）已在门诊和住院环境中广泛应用。该检查是将低频（≤2MHz）换能器置于患者头皮上特定的声学窗上，以可视化颅内动脉血管，并评估在许多不同情况下的脑血流速度及其变化。如今，门诊环境中TCD的一个有效指征是检测右向左分流，这是所谓“反常栓塞”的原因，最常见的是由于卵圆孔未闭，它是55岁以下患者发生的大多数不明原因卒中的原因。TCD还可以使用所谓的“微栓子信号分级评分”对这种分流的严重程度进行分级。因此，TCD是检测卵圆孔未闭的一项重要心脏检查，作为一级检查对指导后续的诊断治疗管理起着重要作用。此外，TCD在神经重症监护实践中也有许多有用的应用。它有助于识别颅内血管狭窄，并评估包括蛛网膜下腔出血、创伤性脑损伤和脑干死亡中的血管痉挛等危急情况。它还用于评估中风后脑血流动力学变化、研究脑压力自动调节以及脑血管运动反应性的临床评估。
