Cerebral microbleeds (CMBs) are defined as hypointense foci visible on
T2*-weighted and susceptible-weighted MRI sequences. CMBs are
increasingly recognised with the widespread use of MRI in healthy
individuals as well as in the context of cerebrovascular disease or
dementia. They can also be encountered in major critical medical
conditions such as in patients requiring extracorporeal mechanical
oxygenation. The advent of MRI-guided postmortem neuropathological
examinations confirmed that, in the context of cerebrovascular disease,
the vast majority of CMBs correspond to recent or old microhaemorrhages.
Detection of CMBs is highly influenced by MRI parameters, in particular
field strength, postprocessing methods used to enhance T2* contrast
and three dimensional sequences. Despite recent progress, harmonising
imaging parameters across research studies remains necessary to improve
cross-study comparisons. CMBs are helpful markers to identify the nature
and the severity of the underlying chronic small vessel disease. In
daily clinical practice, presence and numbers of CMBs often trigger
uncertainty for clinicians especially when antithrombotic treatments and
acute reperfusion therapies are discussed. In the present review, we
discuss those clinical dilemmas and address the value of CMBs as
diagnostic and prognostic markers for future vascular events