Do Clinicians Overestimate the Severity of Intracerebral Hemorrhage?

Background and Purpose- Intracerebral hemorrhage (ICH) has a poorer prognosis than acute ischemic stroke (AIS). However, clinician perception of prognosis may influence treatment decisions and adversely affect outcome. On acute CT, the conspicuity of ICH compared with AIS may lead clinicians to overestimate severity and influence prognostic evaluation. We investigated whether clinicians' estimates of volume, severity, and prognosis from acute imaging differed between ICH and AIS. Methods- CT scans from participants with acute ICH or ischemic stroke were reviewed. Volume was calculated using the ABC/2 method and automated volumetric analysis via specialized imaging software. ICH cases were matched with AIS cases for lesion volume, based on acute (<6 hours) CT for ICH, and 24-hour CT for AIS. Blind to clinical information, clinicians estimated lesion volume to the nearest 5 mL, graded lesion severity from 1 (mild) to 5 (very severe), and estimated 30-day prognosis using the modified Rankin Scale. Results- We compared 33 ICH cases with 33 volume-matched AIS cases. Clinicians overestimated ICH volume and underestimated AIS volumes: mean differences (estimated-actual volume) were +8 mL (±30) for ICH and -8 mL (±27) for AIS ( P<0.001). Observers rated ICH to be of greater severity and poorer prognosis compared with AIS cases: 109 of 265 (41%) ICH cases rated severity categories 4 or 5 compared with 36 of 257 (14%) AIS, P<0.001; estimated modified Rankin Scale of 0 to 2 in 125 of 265 (47%) ICH compared with 190 of 257 (74%) AIS, P<0.001. Results were unaffected by presence of intraventricular blood. Estimated severity and prognosis for ICH remained significantly worse compared with AIS after adjustment for estimated volumes. Conclusions- Clinicians overestimated ICH volume and severity compared with AIS of equivalent volume and also assigned significantly worse prognosis independent of volume estimates.