Abstract
Brain ultrasonography has emerged as a valuable diagnostic and monitoring tool in intensive care, complementing other point-of-care techniques. Transcranial colour-coded duplex (TCCD) offers a rapid, non-invasive, repeatable, and cost-effective bedside me-thod that has gained significant interest among intensivists. TCCD enables visualisation of the circle of Willis and adjacent cerebral arteries, supporting its use in various critical scenarios, including vasospasm following subarachnoid haemorrhage, elevated intracranial pressure, hydrocephalus, acute ischaemic stroke, cerebral circulatory arrest, and certain intracranial haematomas. This manuscript aims to equip intensivists with foundational knowledge to integrate TCCD effectively into their diagnostic arsenal, covering essential Doppler physics, transcranial insonation techniques, and clinical applications of TCCD within intensive care settings.