The role of neuroimaging in brain death diagnosis: a review of radiological protocols and the need for standardization

Abstract

Brain death, defined as the irreversible cessation of all brain functions, including the brainstem, is a critical concept in modern medicine, particularly in the context of organ transplantation. The diagnosis of brain death relies primarily on a thorough clinical neurological examination, which assesses the absence of brainstem reflexes, coma, and apnoea. This paper underscores the critical role of neuroimaging-based ancillary tests in enhancing the accuracy of brain death determination and calls for harmonization of protocols to address existing disparities and improve clinical practice worldwide. The use of ancillary tests, particularly neuroimaging techniques plays a crucial role in confirming the diagnosis, especially in cases where clinical examination is inconclusive or confounded by factors such as drug intoxication or hypothermia. These tests provide objective evidence of the absence of cerebral blood, thereby supporting the clinical determination of brain death. Despite global consensus on the importance of the clinical neurological examination in diagnosing brain death, significant variations exist between countries regarding the use of ancillary tests, the number of required clinical examinations, observation periods, and the number of physicians involved in the determination process. The discrepancies among international guidelines, highlight the need for standardized to ensure consistency and reliability in brain death diagnosis, particularly in the context of organ transplantation, where timely and accurate diagnosis is essential. This literature review examines brain death in the context of organ donation, highlighting the differences in diagnostic protocols worldwide. It emphasises the importance of clinical and neuroimaging tests for accurate diagnosis and the need to standardise international guidelines to improve clinical practice and ensure timely and reliable decisions, particularly in organ transplantation.