BACKGROUND AND PURPOSE: Cerebrovascular reserve (CVR) by both transcranial Doppler ultrasonography (TCD) and quantitative cerebral blood flow (CBF) can identify subgroups of patients at increased risk for stroke. A direct comparison of CVR measurements obtained with both technologies in patients with cerebrovascular occlusive disease is lacking. METHODS: CVRs before and after acetazolamide administration (1 g IV) were measured by TCD insonation of the middle cerebral artery (MCA) and CBF obtained with stable xenon CT (Xe/CT) in 38 patients with carotid occlusive disease. Sensitivity/specificity calculations were based on 2 Xe/CT MCA values: an average over 4 levels and the level with the lowest percent change in CBF. Compromised CVR was defined as no reactivity or a decrease in reactivity. RESULTS: Using the analysis of the systolic TCD, we found that velocity changes compared with the average Xe/CT MCA CVR showed a sensitivity of 33%, specificity of 90.6%, positive predictive value of 54.5%, and negative predictive value of 80%. The sensitivity of TCD compared with the lowest Xe/CT CBF CVR was 35.5%, specificity and positive predictive values were 100%, and negative predictive value was 66.7%. The index of validity was between 72% and 76%. CONCLUSIONS: TCD is much less sensitive than Xe/CT CBF in identifying patients with compromised CVR. This may be a result of the inability of TCD to identify patients with compromised reserves when their MCA blood flow comes from collateral sources. The lack of correlation between TCD and Xe/CT CBF for identifying patients with compromised CVR should be considered when stroke risk assessments are made by TCD.
BACKGROUND AND PURPOSE: Cerebrovascular reserve (CVR) by both transcranial Doppler ultrasonography (TCD) and quantitative cerebral blood flow (CBF) can identify subgroups of patients at increased risk for stroke. A direct comparison of CVR measurements obtained with both technologies in patients with cerebrovascular occlusive disease is lacking. METHODS: CVRs before and after acetazolamide administration (1 g IV) were measured by TCD insonation of the middle cerebral artery (MCA) and CBF obtained with stable xenon CT (Xe/CT) in 38 patients with carotid occlusive disease. Sensitivity/specificity calculations were based on 2 Xe/CT MCA values: an average over 4 levels and the level with the lowest percent change in CBF. Compromised CVR was defined as no reactivity or a decrease in reactivity. RESULTS: Using the analysis of the systolic TCD, we found that velocity changes compared with the average Xe/CT MCA CVR showed a sensitivity of 33%, specificity of 90.6%, positive predictive value of 54.5%, and negative predictive value of 80%. The sensitivity of TCD compared with the lowest Xe/CT CBF CVR was 35.5%, specificity and positive predictive values were 100%, and negative predictive value was 66.7%. The index of validity was between 72% and 76%. CONCLUSIONS:TCD is much less sensitive than Xe/CT CBF in identifying patients with compromised CVR. This may be a result of the inability of TCD to identify patients with compromised reserves when their MCA blood flow comes from collateral sources. The lack of correlation between TCD and Xe/CT CBF for identifying patients with compromised CVR should be considered when stroke risk assessments are made by TCD.
Authors: Csaba Oláh; Zsófia Kardos; Mónika Andrejkovics; Enikő Szarka; Katalin Hodosi; Andrea Domján; Mariann Sepsi; Attila Sas; László Kostyál; Katalin Fazekas; Ágnes Flórián; Katalin Lukács; Ágnes Miksi; Zsuzsanna Baráth; György Kerekes; Márta Péntek; Attila Valikovics; László Tamási; Dániel Bereczki; Zoltán Szekanecz Journal: Rheumatol Int Date: 2019-09-25 Impact factor: 2.631
Authors: Wesley B Baker; Ashwin B Parthasarathy; Kimberly P Gannon; Venkaiah C Kavuri; David R Busch; Kenneth Abramson; Lian He; Rickson C Mesquita; Michael T Mullen; John A Detre; Joel H Greenberg; Daniel J Licht; Ramani Balu; W Andrew Kofke; Arjun G Yodh Journal: J Cereb Blood Flow Metab Date: 2017-05-25 Impact factor: 6.200