Objective To observe the performance and safety of self-developed real-time three-dimensional intracardiac echocardiography(ICE)system(system).Methods The self-developed system was constructed using disposable sterile real-time three-dimensional ICE catheter(catheter)and multifunctional cart-mounted digital ultrasound imaging host(ultrasound host).The diameter of catheter was 10F,with effective length of 90 cm and two-dimensional array transducer array(840 elements)integrated at tip.The ultrasound host was connected to the catheter through matching connector.The performance of this system was evaluated with self-made experimental equipment and standard phantom,and live animal experiment was performed to observe its safety and imaging quality.Results The maximum imaging depth of this system was ≥60 mm.Its axial resolution was ≤1 mm and lateral resolution was ≤1 mm within the depth of 40 mm,the horizontal and vertical geometric position accuracy errors were ≤10％and ≤5％,respectively,while the image geometric distortion was ≤10％,and the measurement volume error was ≤30％.The catheter was successfully inserted into right atrium of pig through femoral vein under ultrasound guidance,smoothly passing through the vascular pathway without any bending or jamming with good controllability.The cardiac images of this system were clear,which completely displayed cardiac chamber structures,and the image resolution met diagnostic requirement.No injury related to interventional procedures was found in laboratory tests nor anatomical results.Conclusion The self-developed ICE system was stable and safe,and initial results showed it could meet clinical application expectations.

Objective To observe the performance and safety of self-developed real-time three-dimensional intracardiac echocardiography(ICE)system(system).Methods The self-developed system was constructed using disposable sterile real-time three-dimensional ICE catheter(catheter)and multifunctional cart-mounted digital ultrasound imaging host(ultrasound host).The diameter of catheter was 10F,with effective length of 90 cm and two-dimensional array transducer array(840 elements)integrated at tip.The ultrasound host was connected to the catheter through matching connector.The performance of this system was evaluated with self-made experimental equipment and standard phantom,and live animal experiment was performed to observe its safety and imaging quality.Results The maximum imaging depth of this system was ≥60 mm.Its axial resolution was ≤1 mm and lateral resolution was ≤1 mm within the depth of 40 mm,the horizontal and vertical geometric position accuracy errors were ≤10％and ≤5％,respectively,while the image geometric distortion was ≤10％,and the measurement volume error was ≤30％.The catheter was successfully inserted into right atrium of pig through femoral vein under ultrasound guidance,smoothly passing through the vascular pathway without any bending or jamming with good controllability.The cardiac images of this system were clear,which completely displayed cardiac chamber structures,and the image resolution met diagnostic requirement.No injury related to interventional procedures was found in laboratory tests nor anatomical results.Conclusion The self-developed ICE system was stable and safe,and initial results showed it could meet clinical application expectations.

Gene therapy represents a promising treatment for the Alzheimer׳s disease (AD). However, gene delivery specific to brain lesions through systemic administration remains big challenge. In our previous work, we have developed an siRNA nanocomplex able to be specifically delivered to the amyloid plaques through surface modification with both CGN peptide for the blood-brain barrier (BBB) penetration and QSH peptide for -amyloid binding. But, whether the as-designed nanocomplex could indeed improve the gene accumulation in the impaired neuron cells and ameliorate AD-associated symptoms remains further study. Herein, we prepared the nanocomplexes with an siRNA against -site amyloid precursor protein-cleaving enzyme 1 (BACE1), the rate-limiting enzyme of A production, as the therapeutic siRNA of AD. The nanocomplexes exhibited high distribution in the A deposits-enriched hippocampus, especially in the neurons near the amyloid plaques after intravenous administration. In APP/PS1 transgenic mice, the nanocomplexes down-regulated BACE1 in both mRNA and protein levels, as well as A and amyloid plaques to the level of wild-type mice. Moreover, the nanocomplexes significantly increased the level of synaptophysin and rescued memory loss of the AD transgenic mice without hematological or histological toxicity. Taken together, this work presented direct evidences that the design of precise gene delivery to the AD lesions markedly improves the therapeutic outcome.