Variant flow patterns in radionuclide cerebral imaging performed for brain death.

Area of Science:

• Neurology
• Radiology
• Medical Imaging

Background:

• Radionuclide cerebral imaging (RCI) is a standard method for evaluating intracranial blood flow in suspected brain death cases.
• Previous literature has described various RCI flow patterns, but a comprehensive review focused on brain death diagnosis is lacking.

Purpose of the Study:

• To review and discuss variant radionuclide cerebral imaging patterns observed in patients with clinically suspected brain death.
• To clarify the significance of different flow patterns in the context of establishing a diagnosis of brain death.

Main Methods:

• Retrospective analysis of 115 radionuclide cerebral imaging studies performed on 95 patients over a six-year period.
• Observation and categorization of various intracranial blood flow patterns, including normal, absent, isolated superior sagittal sinus activity, luxury perfusion, hypoperfusion, hemiperfusion, and jugular venous reflux.

Main Results:

• Demonstrable intracranial blood pool activity generally excludes a diagnosis of brain death.
• Jugular venous reflux was identified as a pattern that renders the RCI examination uninterpretable.
• While RCI cannot assess basilar brain flow, it remains a valuable tool for supporting the clinical diagnosis of brain death.

Conclusions:

• Radionuclide cerebral imaging is a valuable adjunct in the diagnosis of brain death, offering insights into intracranial blood flow.
• Understanding variant flow patterns, such as jugular venous reflux, is crucial for accurate interpretation and diagnosis.
• Despite limitations in evaluating basilar flow, RCI contributes significantly to establishing the clinical diagnosis of brain death.