Transcranial Doppler ultrasound: Clinical applications from neurological to cardiological setting

Abstract

Transcranial Doppler (TCD) ultrasonography is a rapid, noninvasive, real‐time, and low‐cost imaging technique. It is performed with a low‐frequency (2 MHz) probe in order to evaluate the cerebral blood flow (CBF) and its pathological alterations, through specific acoustic windows. In the recent years, TCD use has been expanded across many clinical settings. Actually, the most widespread indication for TCD exam is represented by the diagnosis of paradoxical embolism, due to patent foramen ovale, in young patients with cryptogenic stroke. In addition, TCD has also found useful applications in neurological care setting, including the following: cerebral vasospasm following acute subarachnoid hemorrhage, brain trauma, cerebrovascular atherosclerosis, and evaluation of CBF and cerebral autoregulation after an ischemic stroke event. The present review aimed to describe the most recent evidences of TCD utilization from neurological to cardiological setting.

The Incremental Role of Multiorgan Point-of-Care Ultrasounds in the Emergency Setting

“…The ONSD is measured behind the globe, using the optic disc as a reference point together with the central retinal artery color Doppler technique, which helps to identify the optic nerve [126]. Moreover, the blood flow velocities in the main cerebral arteries, measured through the transcranial Doppler (TCD) technique, help to identify intracranial hypertension by identifying an elevation in both the pulsatility index (PI) and the resistive index (RI) ( [127,128]. In brief, the combination of data such as an optic nerve sheath diameter (ONSD) of >6 mm and a pulsatility index (PI) of >1.4 strongly correlates with an intracranial pressure of >22 mmHg, which identifies intracranial hypertension [129].…”