Developments of many cardiovascular problems have been shown to have a close relationship with arterial flow conditions.However,current ultrasound/Doppler imaging techniques cannot resolve the complex nature of arterial blood flow.We have recently developed a novel contrast-based echo particle imaging technique（Echo PIV） without angel dependence for non-invasively measuring multi-component flow vectors.This study introduces the Echo PIV principles,system characterization and utility examination to characterize hemodynamics in pipe laminar flow and rotating flow.Echo PIV measurement results show its capability to resolve the complex hemodynamics including proximal flow velocity vectors,and velocity mapping. The Echo PIV method provides an easy,direct and accurate means of quantitatively yet non-invasively characterizing the complex vascular hemodynamics.
A microfluidic device was developed to precisely transport the microbubbles by introducing phase-shifts to a t...
Long Meng Fei-Yan Cai Hai-Rong Zheng~* Paul C.Lauterbur Research Center for Biomedical Imaging,Institute of Biomedical and Health Engineering,Shenzhen Institutes of Advanced Technology,Chinese Academy of Sciences,Shenzhen 518055
The association of circulating levels of cystatin C(CysC)and risk of recurrent cardiovascular events in patients with preexisting coronary heart disease are uncertain.To qualitatively and quantitatively address this issue,we performed a random meta-analysis of results from prospective studies on the topic.We searched electronic and printed sources(up to 16 October 2011)using keywords and retrieved articles for seven prospective studies according to the selection criteria.Data were abstracted and meta-analysis was performed using the random-effects model(RevMan 5.0.23 software).The cohorts involved 4,576 patients with preexisting coronary heart disease(CHD)and normal or mild chronic kidney disease,and follow-up ranged from 5.6 to 40.6 months.Highest versus lowest baseline CysC level was significantly associated with increased risk of cardiovascular events(OR 2.30,95%CI 1.80–2.94),all-cause mortality(OR 5.69,95%CI 3.70–8.74),but not with recurrent MI(OR 1.75,95%CI 0.77–4.00).In heterogeneity testing for studies reporting cardiovascular events and all-cause mortality,no significant heterogeneity was found,and exclusion of any single study did not alter the overall finding.For risk of recurrent MI,significant heterogeneity was found among the five trials(v2=13.16,P=0.01,I2=70%)and exclusion of the Taglieri et al.[12]study from the analysis resulted in a rise in relative risk(OR 2.36,95%CI 1.09–5.15).In conclusion,for patients with established CHD,high baseline level of CysC is associated with increased risk of cardiovascular events and all-cause death during long-term follow-up.
