Learning objectives
To evaluate the main findings in hipoxic brain injury after postnatal cardiac arrest,
both in CT and MRI.
To document the timing of the imaging findings,
as theycan change rapidlyafter the event,
ranging from the earliest to the latestfindings,
including the delayed postanoxic leukoencephalophaty.
To review the main differential diagnosis entities.
Background
Brain injury caused by hipoxia during cardiac arrest is the most important cause of neurologic disability and mortality in this pathology.
Its severity will determine the patient´s long-term prognosis,
and sometimes also the medical attitude; it is necessary to identify which patients have no likelihood of neurological recovery,
to justify early withdrawal of life support.
Therefore,radiologist role in hypoxic brain damage is usually crucial.
Unfourtunately,
its radiological diagnosis can be complicated,
because findings are frequently bilateral,
symmetrical and subtle.
Findings and procedure details
Primary brain damage after a cardiac arrest is due to the reduction in overall cerebral blood supply,
followed by a heterogeneous cascade of events that culminates insecondary brain damage and neuronal death.
Secondary damage occurs hours or days later,
and it is due to reperfusion,
microcirculation dysfunction,
loss of cerebral autoregulation,
hypoxemia,
hyperoxia,
hyperthermia and fluctuations of carbon dioxide levels.
Within the brain,
there are some areas more vulnerableto blood supply deficit than others,beingthe grey matter the most susceptible because itshighest oxygen and glucose demand....
Conclusion
Global hipoxic brain injury after cardiac arrest and its severity determine the prognosis and sometimes treatment of these patients.
Recognition of the radiological findings is critical because of this reason.
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