SENSITIVITY AND SPECIFICITY OF FLUID-BLOOD LEVELS FOR COAGULOPATHY INACUTE INTRACEREBRAL HEMATOMAS

PURPOSE: To characterize the imaging features of intracerebral hemorrh ages in patients with coagulopathies that alter prothrombin time or pa rtial thromboplastin time. METHODS: A fluid-blood level was defined as a horizontal interface between hypodense bloody serum layered above h yperdense settled blood. The prevalence of fluid-blood levels in acute intracerebral hemorrhages was determined on third-generation CT scans in 32 patients with elevation in prothrombin time or partial thrombop lastin time. This was compared with the frequency of fluid-blood level s in 185 patients with intracerebral hemorrhage in which there was no laboratory evidence of coagulopathy. RESULTS: The probability of findi ng a fluid-blood level in an intracerebral hemorrhage of a patient wit h abnormal prothrombin time or partial thromboplastin time was 59% (se nsitivity). The probability that there will be no fluid-blood level in a patient with a normal prothrombin time and partial thromboplastin t ime was 98% (specificity). CONCLUSION: Fluid-blood levels in acute int racerebral hemorrhage are moderately sensitive to the presence of coag ulopathy (ie, abnormal prothrombin time and partial thromboplastin tim e) and highly specific for this condition. Thus, an intracerebral hemo rrhage with a fluid-blood level should prompt a thorough search for co agulopathy because early treatment of this condition may improve the 4 0% mortality in these patients. Caution should be used to distinguish the horizontal interface of a fluid-blood level from a clot with a fla t top. A decubitus CT is useful in these rare instances.