Abstract TP48: Caveats When Using the CT Perfusion Derived Cerebral Blood Volume Lesion to Help Guide Thrombolysis Treatment in Acute Ischemic Stroke
Background: Very low CT perfusion (CTP)-derived cerebral blood volume (CBV) has shown promise in defining infarction and may also be used as a predictor of hemorrhagic transformation (HT). We sought to determine whether the CTP-CBV defect (CBVD) correlates with final infarct volume, as defined by a 3 month NCCT, and whether the CBV defect volume is associated with hemorrhagic transformation (HT).
Methods: CBV defect (CBVD) volumes were outlined on all CBV functional maps using previously established CBV thresholds for infarction, CBV<1.1 ml•100g-1 and CBV<0.75 ml•100g-1 for gray and white matter, respectively. Final infarct volumes were traced on 3 month NCCT. Patients were separated into two sub-groups according to the percent truncation of the ischemic tissue TDC (ITDC) calculated at onset. A model of linear regression was used to observe whether the admission CBVD could predict final infarct volume on NCCTD. Average admission CBVD volumes for patients with hemorrhagic infarction (HI), parenchymal hematoma (PH) and no HT were calculated and compared.
Results: Thirty patients were included. There were 21/30 patients (70%) whose onset CBVD volume was less than the NCCTD at 3 months; mean volume difference was 24.2 [range(1.5 to 88mL)]. Six of these patients had truncation of the ITDC at onset. There were 9 patients (30%) whose onset CBVD volume was larger than the final infarct volume from the 3 month NCCT (NCCTD); mean volume difference was -9.9mL [range(-28.5 to -0.2mL)]. Of these 9/30 patients, 8 had truncation of the ITDC at admission. For the onset CBVD versus NCCTD, the coefficients of determination (R2) were 0.56, 0.70 and 0.46 for all patients, truncation positive and truncation negative groups, respectively. 30% of patients had hyperemia at onset, defined as an increase in CBV relative to the contralateral side. HT was observed in 13/30 patients: 8 HI, 5 PH. Symptomatic intracerebral hemorrhage was found in 1 patient. Average CBVD volumes for HI, PH and non-HT groups were 15.7±17.4, 47.1±29.9 and 16.3±27.0, respectively (p > 0.05).
Conclusions: The acute CBV defect remains an important diagnostic parameter for acute ischemic stroke if both truncation of the ITDC and variable perfusion states within tissue destined to infarct are taken into account.
- © 2012 by American Heart Association, Inc.