Abstract W P27: Quantitative Measurement Of Blood Flow Around Intravascular Thrombus Using CT Perfusion T0 Maps
Introduction: Anterograde blood flow around thrombus and extent of retrograde collateral filling can affect thrombus lysis with IV tPA. Current assessment of blood flow around thrombus is however very subjective. The aim of the present study is to validate a newly devised method to quantify blood flow around thrombus using CT perfusion (CTP) T0 maps.
Methods: From the Prove-IT stroke-imaging database, perfusion CT and DSA images of stroke patients treated with IV tPA and/or IA thrombolysis were analyzed. We generated maps that measure delay in arrival time of contrast within the intracranial arterial tree (T0 maps) from that of the chosen arterial input function. A “positive sloped” regression line of T0 values from distal clot interface to at least 14 pixels (median 68 pixels) along the artery profile indicated presence of occult anterograde flow. Anterograde flow thus measured using the T0 maps was compared with anterograde flow assessed on first angiography of subsequent IA procedure.
Results: Of 37 patients (mean age 66 ± 13.5 years, 20 female), 35 (94.6%) were treated with IV tPA before DSA. Median time from CTP to first run angiography was 83 mins (IQR 53-100 mins). Positive slope were noted in 10 patients. Patients who had anterograde flow on first angiography were 10. Compared with anterograde flow on first run angio, positive slope on T0 map had a sensitivity of 80%, specificity of 92.6% and a positive predictive value of 80% and negative predictive value of 92.6%. In patients with anterograde flow on first angiography, median T0 time at proximal clot interface was 0.1 seconds (IQR 0-0.1) and at distal clot interface was 0.7 seconds (IQR 0.5-3.1). In patients without any anterograde flow on first angio, median T0 time at proximal clot interface was 0.1 seconds (IQR 0-0.3) while that at distal clot interface was 3.7 seconds (IQR 2.1-5.6).
Conclusions: The slope method on CTP T0 maps and measurement of T0 values around clot reliably measure presence of anterograde blood flow through thrombus.
Author Disclosures: S. Ahn: Research Grant; Significant; Dr. Ahn received the research fund from Chosun University, Gwang Ju, South Korea.. C. D. d’Esterre: None. E.M. Qazi: None. M. Goyal: None. A.M. Demchuk: Honoraria; Modest; Covidien honoraria for CME. Research Grant; Significant; Unrestricted grant for ESCAPE trial: Covidien. T.Y. Lee: None. B.K. Menon: None.
- © 2015 by American Heart Association, Inc.