👉 Struck fluid, also known as "striated" or "salt-and-pepper" fluid, is a type of fluid found in the subarachnoid space, the area between the arachnoid mater and the pia mater of the central nervous system. It appears as a granular or speckled pattern on imaging studies, resembling salt and pepper due to the presence of hemosiderin-laden macrophages, which are remnants of old blood. This fluid is typically the result of bleeding into the subarachnoid space, often caused by a ruptured aneurysm or arteriovenous malformation (AVM). The presence of struck fluid indicates a significant and often life-threatening hemorrhage, as it suggests the blood has not yet coagulated and is still circulating within the subarachnoid space, posing a risk of increased intracranial pressure and potential neurological damage.
