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        find Keyword "coil" 15 results
        • Predicting risk of severe elastic recoil after percutaneous transluminal angioplasty in femoropopliteal artery disease: based on intravascular ultrasound analysis

          ObjectiveTo identify risk factors for severe elastic recoil after percutaneous transluminal angioplasty (PTA) in the femoropopliteal artery disease based on intravascular ultrasound (IVUS) imaging and to develop a risk prediction model. MethodsA retrospective analysis was conducted on the clinical data from the patients with femoropopliteal artery disease treated at the First Affiliated Hospital of Chongqing Medical University from September 2020 to February 2022. Based on the IVUS images, a multivariate logistic regression analysis was conducted to identify the risk factors for severe elastic recoil in the patients with femoropopliteal artery disease after PTA. A nomogram prediction model was established to predict the occurrence of severe elastic recoil, and the area under receiver operating characteristic curve (AUC) was used to evaluate its ability to distinguish the occurrence of severe elastic recoil, which was validated using a calibration curve. ResultsA total of 34 patients with femoropopliteal artery disease who received PTA treatment were enrolled. Of the 803 vessel slices were analyzed, 451 (56.16%) demonstrated severe elastic recoil on IVUS imaging. The multivariate logistic regression analysis showed that the increased plaque burden, luminal eccentric index, external elastic membrane remodeling index, and the external elastic membrane-balloon area ratio were the risk factors for the occurrence of severe elastic recoil (P<0.05). The AUC of the nomogram prediction model based on these risk factors exhibited moderate discrimination [AUC (95%CI)=0.775 (0.732, 0.818)]. The predicted probability of the nomogram model for severe elastic recoil was in a good agreement with the actual probability (P=0.862). ConclusionThe severe elastic recoil prediction model developed in this study, based on IVUS imaging data, can effectively identify high-risk factors for severe elastic recoil after PTA in patients with femoropopliteal artery disease, demonstrating a moderate predictive discrimination capability.

          Release date:2025-04-21 01:06 Export PDF Favorites Scan
        • CT-guided Hook-wire versus microcoil localization in the pulmonary nodules surgery: A systematic review and meta-analysis

          ObjectiveTo systematically evaluate the application effect of CT-guided Hook-wire localization and CT-guided microcoil localization in pulmonary nodules surgery. MethodsThe literatures on the comparison between CT-guided Hook-wire localization and CT-guided microcoil localization for pulmonary nodules were searched in PubMed, EMbase, The Cochrane Library, Web of Science, Wanfang, VIP and CNKI databases from the inception to October 2021. Review Manager (version 5.4) software was used for meta-analysis. The Newcastle-Ottawa Scale (NOS) was used to evaluate the quality of studies.ResultsA total of 10 retrospective cohort studies were included, with 1 117 patients including 473 patients in the CT-guided Hook-wire localization group and 644 patients in the CT-guided microcoil localization group. The quality of the studies was high with NOS scores>6 points. The result of meta-analysis showed that the difference in the localization operation time (MD=0.14, 95%CI ?3.43 to 3.71, P=0.940) between the two groups was not statistically significant. However, the localization success rate of the Hook-wire group was superior to the microcoil group (OR=0.35, 95%CI 0.17 to 0.72, P=0.005). In addition, in comparison with Hook-wire localization, the microcoil localization could reduce the dislocation rate (OR=4.33, 95%CI 2.07 to 9.08, P<0.001), the incidence of pneumothorax (OR=1.62, 95%CI 1.12 to 2.33, P=0.010) and pulmonary hemorrhage (OR=1.64, 95%CI 1.07 to 2.51, P=0.020). ConclusionAlthough Hook-wire localization is slightly better than microcoil localization in the aspect of the success rate of pulmonary nodule localization, microcoil localization has an obvious advantage compared with Hook-wire localization in terms of controlling the incidence of dislocation, pneumothorax and pulmonary hemorrhage. Therefore, from a comprehensive perspective, this study believes that CT-guided microcoil localization is a preoperative localization method worthy of further promotion.

          Release date:2023-06-13 11:24 Export PDF Favorites Scan
        • Therapy experience of multiple interventional technologies for visceral artery aneurysms in 32 cases

          ObjectiveTo investigate treatment methods and effect of endovascular interventional therapy for visceral artery aneurysms.MethodsThe clinical data of 32 patients with visceral artery aneurysms, who were treated in the No. 960 Hospital of PLA from February 2011 to April 2018, were retrospectively analyzed. It was proveded by the CT or digital subtraction angiography before the interventional therapy. The implantation of covered stent, coil embolization together with stent implantation, double stents placement or pure coil embolization were performed. The postoperative antithrombotic therapy was adopted in the patients accepted the stent implantation. The CT angiography was performed on the month of 1, 6, 12, 24 or the patient was uncomfortable after the treatment to evaluate the obstruction condition of the aneurysms, stent blood flow, and branches arteries, etc..ResultsThe success rate of the endovascular interventional therapy was 100%. In the 11 patients underwent the implantation of covered stent, the postoperative angiography showed that the stent lumen was patent and the aneurysm was not visualized. In the 9 patients underwent the coil embolization together with stent implantation and 3 patients underwent the double stents placement, the postoperative angiography results of the aneurysm showed that it was faintly visualized and the branch arteries were not involved. In the 9 patients underwent the pure coil embolization, the postoperative angiography showed that the aneurysm was not visualized. No perioperative mortality or procedure related complications occurred. No case was lost during the follow-up of a median period of 25.5 (6–48) months. During the follow-up, one patient developed the mild abdominal pain in one month, which disappeared after the symptomatic medication management. Except for 1 patient developed the mild stent stenosis (<30%) on the 12th month after the procedure, the stent and the branch arteries of the other patients were completely patent, and no aneurysms recurred.ConclusionFor treatment of visceral artery aneurysms, endovascular interventional therapy is safe and effective and shows an excellent short-term and mid-term effects.

          Release date:2019-03-18 05:29 Export PDF Favorites Scan
        • Intraoperative sac embolizaion with coils and fibrin glue during endovascular aneurysm repair for preventing postoperative type Ⅱ endoleak

          Objective To investigate the technical feasibility and effectiveness of intraoperative sac embolizaion with coils and fibrin glue for preventing type Ⅱ endoleak after endovascular aneurysm repair (EVAR). Methods A patient with abdominal aortic aneurysm (AAA), which had high risk of type Ⅱ endoleaks, was treated with combined packing of coils and fibrin glue in order to prevent type Ⅱ endoleak after EVAR. Percutaneous catheter preset and balloon occlusion were used to ensure accurate packing. Results At the end of the operation, the angiography showed that the blood flow of the stent and distal artery was unobstructed, there was no type Ⅰ and Ⅲ endoleaks, and delayed angiogram showed no collateral circulation of aneurysm. The procedure was successful. The operative duration was 120 min and the blood loss was only 20 mL. No complications such as colonic ischemia and ectopic embolism occurred, and the patient was discharged on 3 days after operation. At 6 months after follow-up, the computerized topographic angiography showed that the aneurysm cavity was completely thrombotic, without type II endoleak, and the diameter and volume of aneurysm were reduced. Conclusions The technique of intraoperative sac embolizaion with coils and fibrin glue during EVAR is safe and effective to prevent postoperative endoleaks, which is simple and feasibility. Intraoperative indwelling catheter and balloon blocking are the key points of successful implementation of this technique.

          Release date:2023-02-02 08:55 Export PDF Favorites Scan
        • Spherical measurement-based analysis of gradient nonlinearity in magnetic resonance imaging

          The gradient field, one of the core magnetic fields in magnetic resonance imaging (MRI) systems, is generated by gradient coils and plays a critical role in spatial encoding and the generation of echo signals. The uniformity or linearity of the gradient field directly impacts the quality and distortion level of MRI images. However, traditional point measurement methods lack accuracy in assessing the linearity of gradient fields, making it difficult to provide effective parameters for image distortion correction. This paper introduced a spherical measurement-based method that involved measuring the magnetic field distribution on a sphere, followed by detailed magnetic field calculations and linearity analysis. This study, applied to assess the nonlinearity of asymmetric head gradient coils, demonstrated more comprehensive and precise results compared to point measurement methods. This advancement not only strengthens the scientific basis for the design of gradient coils but also provides more reliable parameters and methods for the accurate correction of MRI image distortions.

          Release date:2025-02-21 03:20 Export PDF Favorites Scan
        • A Detection Method of Liver Iron Overload Based on Static Field Magnetization Principle

          Magnetic induction method aims at the noninvasive detection of liver iron overload by measuring the hepatic magnetic susceptibility. To solve the difficulty that eddy current effects interfere with the measurement of magnetic susceptibility, we proposed an improved coil system based on the static field magnetization principle in this study. We used a direct current excitation to eliminate the eddy current effect, and a rotary receiver coil to get the induced voltage. The magnetic field for a cylindrical object due to the magnetization effect was calculated and the relative change of maximum induced voltage was derived. The correlation between magnetic susceptibility of object and maximum magnetic flux, maximum induced voltage and relative change of maximum induced voltage of the receiver coil were obtained by simulation experiments, and the results were compared with those of the theory calculation. The contrast shows that the simulation results fit the theory results well, which proves our method can eliminate the eddy current effect effectively.

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        • Application of preoperative computed tomography-guided embolization coil localization of pulmonary nodules in thoracoscopic pulmonectomy: A randomized controlled trial

          Objective To explore the diagnostic and treatment value of computed tomography (CT)-guided embolization coil localization of pulmonary nodules accurately resected under the thoracoscope. Methods Between October 2015 and October 2016, 40 patients with undiagnosed nodules of 15 mm or less were randomly divided into a no localization group (n=20, 11 males and 9 females with an average age of 60.50±8.27 years) or preoperative coil localization group (n=20, 12 males and 8 females with an average age of 61.35±8.47 years). Coils were placed with the distal end deep to the nodule and the superficial end coiled on the visceral pleural surface with subsequent visualization by video-assisted thoracoscopic (VATS). Nodules were removed by VATS wedge excision using endo staplers. The tissue was sent for rapid pathological examination, and the pulmonary nodules with definitive pathology found at the first time could be defined as the exact excision. Results The age, sex, forced expiratory volume in the first second of expiration, nodule size/depth were similar between two groups. The coil group had a higher rate of accurate resection (100.00% vs. 70.00%, P=0.008), less operation time to nodule excision (35.65±3.38 minvs. 44.38±11.53 min,P=0.003), and reduced stapler firings (3.25±0.85vs. 4.44±1.26,P=0.002) with no difference in total costs. Conclusion Preoperative CT-guided coil localization increases the rate of accurate resection.

          Release date:2017-11-01 01:56 Export PDF Favorites Scan
        • Study on the relaxing effect of salbutamol combined with Y-27632 on porcine airway smooth muscle

          Objective To explore the effect of salbutamol combined with Rho associated coiled-coil forming protein kinase (ROCK) inhibitor Y-27632 on airway smooth muscle and to find a new way for drug treatment of asthma. Methods Pig tracheal smooth muscle tissue strips were prepared, and after treatment they were divided into an electrical stimulation group (Fmax, 50%Fmax) and a blank group. The smooth muscle tissue strips were quickly frozen to determine the expression level of Rock-Ⅱ and the phosphorylation level of MLC20. The Fmax and 50%Fmax electrical stimulation groups were divided into a blank group, a salbutamol group, a Y-27632 group, and a salbutamol combined with Y-27632 group according to different intervention drugs. The relaxation of smooth muscle strips was observed. Results In the blank group, 50%Fmax group and Fmax group, the expression level of Rock-Ⅱ and the phosphorylation of MLC20 in smooth muscle tissue showed an increasing trend, with statistically significant differences (P<0.05). In the 4 subgroups of the 50%Fmax group intervention with different drugs (blank group, salbutamol group, Y-27632 group, salbutamol plus Y-27632 group), the diastolic ratio smooth muscle tissue strips showed an increasing trend. When the time reaches 10 min, the diastolic ratios were 0.7%, 2.5%, 6.0%, and 15.0%. the diastolic ratios were 1.8%, 4.5%, 7.5%, and 21.0% at the time of 20 min. the diastolic ratios were 1.9%, 7.5%, 7.9% and 22.0% at the time of 40 min. the diastolic ratios were 2.0%, 8.0%, 8.8%, and 22.5% at the time of 60 min. In the four subgroups of the Fmax electrical stimulation group, the relaxation ratio of smooth muscle tissue strips also showed an increasing trend. When the time reaches 10 min, the diastolic ratios were 1.0%, 3.0%, 7.0%, and 17.0%. the diastolic ratios were 2.6%, 5.5%, 9.0%, and 24.0% at the time of 20 min. the diastolic ratios were 2.8%, 9.0%, 9.5%, and 27.5% at the time of 40 min. diastolic ratios were 2.9%, 10.5%, 10.5%, and 28.0% at the time of 60 min. The analysis of difference between groups showed that at the same time, the diastolic ratio of smooth muscle in salbutamol combined with Y-27632 group was significantly higher than that in salbutamol alone group and Y-27632 group (P<0.05). In addition, the smooth muscle diastolic ratio of combined intervention was also better than the the mathematical sum effect of both single drug intervention (P<0.05). Conclusions The contractility and intensity of smooth muscle are positively correlated with the expression level of ROCK and the phosphorylation level of MLC20. Salbutamol combined with Y-27632 can enhance the relaxation of porcine airway smooth muscle, which may have a synergistic effect.

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        • Effectiveness and Safety of Power Chain versus Nickel Titanium Coil Springs in Closing Dental Extraction Space: A Meta-Analysis

          Objective To systematically review the effectiveness and safety of power chain vs. nickel titanium coil springs in closing dental extraction space. Methods Databases including PubMed, EMbase, The Cochrane Library, Chinese Biomedicine Literature Database, Chinese Scientific Journals Full-text Database, and Chinese Journal Full-text Database were searched to collect the randomized controlled trials (RCTs) on comparing power chain with nickel titanium coil springs published before February 2012. Two reviewers independently screened literature, extracted data and assessed the quality of the included studies. Then meta-analysis was conducted using RevMan 5.0 software. Results A total of 4 RCTs involving 122 patients were included. The results of meta-analyses showed that there was a significant difference in the rate of space closure between the two groups (MD=0.30 mm per month, 95%CI 0.17 to 0.44, Plt;0.000 1); The results of subgroup analyses indicated that, both high-quality trials (MD=0.20, 95%CI 0.07 to 0.34, P=0.003) and low quality trials (MD=0.40, 95%CI 0.30 to 0.50, Plt;0.000 01) showed no significant difference in the rate of space closure. Conclusion Current clinical evidence indicates nickel titanium coil spring is superior to power chain in the rate of space closure, but its long-term effect still needs to be proved by more large-scale RCTs.

          Release date:2016-09-07 10:58 Export PDF Favorites Scan
        • Deep transcranial magnetic stimulation coil design and multi-objective slime mould algorithm

          The therapeutic effects of transcranial magnetic stimulation (TMS) are closely related to the structure of the stimulation coil. Based on this, this study designed an A-word coil and proposed a multi-strategy fusion multi-objective slime mould algorithm (MSSMA) aimed at optimizing the stimulation depth, focality, and intensity of the coil. MSSMA significantly improved the convergence and distribution of the algorithm by integrating a dual-elite guiding mechanism, a hyperbolic tangent control strategy, and a hybrid polynomial mutation strategy. Furthermore, compared with other stimulation coils, the novel coil optimized by the MSSMA demonstrates superior performance in terms of stimulation depth. To verify the optimization effects, a magnetic field measurement system was established, and a comparison of the measurement data with simulation data confirmed that the proposed algorithm could effectively optimize coil performance. In summary, this study provides a new approach for deep TMS, and the proposed algorithm holds significant reference value for multi-objective engineering optimization problems.

          Release date:2025-08-19 11:47 Export PDF Favorites Scan
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          2. 射丝袜