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61.
62.
矩形外固定器治疗桡骨远端粉碎性骨折 总被引:1,自引:1,他引:1
本文报告一种新的矩形外固定器,1992年以来,治疗5例桡骨远端粉碎性骨折,经临床观察和随访,治疗结果较满意。外固定针固定在2~3掌骨和桡骨干上。根据需要,闭合复位后,可利用外固定器行加压或撑开固定,该固定器具有操作简单和固定牢固等优点,很适宜治疗桡骨远端粉碎性骨折 相似文献
63.
Hyun Joo Shin Yong Eun Chung Young Han Lee Jin-Young Choi Mi-Suk Park Myeong-Jin Kim Ki Whang Kim 《Korean journal of radiology》2013,14(6):886-893
Objective
To evaluate the feasibility of sinogram-affirmed iterative reconstruction (SAFIRE) and automated kV modulation (CARE kV) in reducing radiation dose without increasing image noise for abdominal CT examination.Materials and Methods
This retrospective study included 77 patients who received CT imaging with an application of CARE kV with or without SAFIRE and who had comparable previous CT images obtained without CARE kV or SAFIRE, using the standard dose (i.e., reference mAs of 240) on an identical CT scanner and reconstructed with filtered back projection (FBP) within 1 year. Patients were divided into two groups: group A (33 patients, CT scanned with CARE kV); and group B (44 patients, scanned after reducing the reference mAs from 240 to 170 and applying both CARE kV and SAFIRE). CT number, image noise for four organs and radiation dose were compared among the two groups.Results
Image noise increased after CARE kV application (p < 0.001) and significantly decreased as SAFIRE strength increased (p < 0.001). Image noise with reduced-mAs scan (170 mAs) in group B became similar to that of standard-dose FBP images after applying CARE kV and SAFIRE strengths of 3 or 4 when measured in the aorta, liver or muscle (p ≥ 0.108). Effective doses decreased by 19.4% and 41.3% for groups A and B, respectively (all, p < 0.001) after application of CARE kV with or without SAFIRE.Conclusion
Combining CARE kV, reduction of mAs from 240 to 170 mAs and noise reduction by applying SAFIRE strength 3 or 4 reduced the radiation dose by 41.3% without increasing image noise compared with the standard-dose FBP images. 相似文献64.
Objectives:
To investigate the accuracy of cone beam CT (CBCT) images obtained with and without artefact reduction (AR) in detecting simulated buccal peri-implant and buccal periodontal defects.Methods:
42 implants inserted into edentulous mandibles, and 38 teeth present in dry mandibles were used. Simulated buccal peri-implant defects (n = 22) and buccal periodontal defects (n = 22) were prepared. 20 implants and 18 teeth without simulated defects were the control group. Images of the mandibles were obtained using a Planmeca ProMax® 3D Max CBCT unit (Planmeca Oy, Helsinki, Finland). Image reconstructions were prepared without and with low, medium and high AR modes. Images were viewed randomly by six observers twice for the presence of defects. Kappa coefficient was calculated. F2_LD_F1 design for non-parametric analysis of longitudinal data was used. Area under curves (AUCs) were calculated for each observer. Significance level was taken as α = 0.05.Results:
Intraobserver kappa ranged from 0.140 to 0.792 for peri-implant and from 0.189 to 1.0 for periodontal defects. All factors were statistically significant (p < 0.001), except for image mode and implant brand. Pairwise interactions were found between periodontal defects and peri-implant defects (p < 0.001), observers (p < 0.001), observer and image mode (p < 0.001), defect model and observer (p < 0.001) and defect model, image mode and observer (p = 0.04). AUC values ranged from 0.39 to 0.52 for peri-implant and from 0.45 to 0.71 for periodontal defects. Higher AUC values were found for periodontal defects than for peri-implant defects.Conclusions:
Buccal peri-implant defects were more difficult to detect than buccal periodontal defects. No difference was found among CBCT images obtained with and without AR modes. 相似文献65.
运动员减体重期维生素代谢的改变及其补充 总被引:4,自引:0,他引:4
对34名摔跤运动员减体重期维生素代谢的研究表明,运动员减体重期摄入的VA、VB1、VB2、PP、VC都明显低于运动员供给量标准。血中VA浓度减重前后基本一致,暗适应时间稍延长,24h尿中VB1;、VB2、VC排出量减体重后明显低于减体重前。尿中PP排出量减体重前后基本一样,任意克肌酐尿中VB1、VB2、PP、VC排出量与24h尿中这几种维生素排出量结果基本一致,进一步说明了结果的可靠性。服用减重营养饼干后,血中VA含量减体重后高于减前,适应时间减体重前后基本一致,但短于普通饼干组。尿中VB1、VB2、PP、VC排出量减体重后高于减重前,且均高于吃普通饼干对照组。说明减体重营养饼干补充了运动员减体重造成的各种维生素的不足和丢失,满足了运动员减体重对维生素的需要。 相似文献
66.
67.
Dose reduction in CT examination of children by an attenuation-based on-line modulation of tube current (CARE Dose) 总被引:3,自引:0,他引:3
Greess H Nömayr A Wolf H Baum U Lell M Böwing B Kalender W Bautz WA 《European radiology》2002,12(6):1571-1576
In a controlled patient study we investigated the potential of attenuation-based on-line modulation of the tube current to reduce milliampere values (mAs) in CT examinations of children without loss of image quality. mAs can be reduced for non-circular patient cross sections without an increase in noise if tube current is reduced at those angular positions where the patient diameter and, consequently, attenuation are small. We investigated a technical approach with an attenuation-based on-line control for the tube current realised as a work-in-progress implementation. The CT projection data are analysed in real time to determine optimal mAs values for each projection angle. We evaluated mAs reduction for 100 spiral CT examinations with attenuation-based on-line modulation of the tube current in a group of children. Two radiologists evaluated image quality by visual interpretation in consensus. We compared the mAs values read from the CT scanner with preset mAs of a standard protocol. Four different scan regions were examined in spiral technique (neck, thorax, abdomen, thorax and abdomen). We found the mAs product to be reduced typically by 10-60% depending on patient geometry and anatomical regions. The mean reduction was 22.3% (neck 20%, thorax 23%, abdomen 23%, thorax and abdomen 22%). In general, no deterioration of image quality was observed. There was no correlation between the age and the mean mAs reduction in the different anatomical regions. By classifying the children respectively to their weight, there is a positive trend between increasing weight and mAs reduction. We conclude that mAs in spiral CT examinations of children can be reduced substantially by attenuation-based on-line modulation of the tube current without deterioration of image quality. Attenuation-based on-line modulation of tube current is efficient and practical for reducing dose exposure to children. 相似文献
68.
Digital subtraction in gadolinium-enhanced MR imaging of the brain: a method to reduce contrast dosage 总被引:2,自引:0,他引:2
Chan JH Tsui EY Chan CY Lai KF Chau LF Fong D Mok CK Cheung YK Wong KP Yuen MK 《European radiology》2002,12(9):2317-2321
The aim of the study was to investigate the feasibility of using digital subtraction in contrast-enhanced MR imaging of the brain to reduce the MR contrast dosage without jeopardizing patient care. Fifty-two patients with intracranial lesions, either intra-axial or extra-axial, detected by computerized tomography were selected for contrast-enhanced MR imaging with half-dose and full-dose of gadopentetate dimeglumine. The half-dose unsubtracted, full-dose unsubtracted, and half-dose subtracted MR images were visually assessed by counting the number of enhancing brain lesions in the images and quantitatively analyzed by computing their lesion contrast-to-background ratios (CBR). The visual conspicuity of the half-dose subtracted MR images was comparable to that of the full-dose unsubtracted MR images ( p>0.05), whereas the CBR of the half-dose subtracted images was approximately two to three times higher than that of the full-dose unsubtracted images. The half-dose subtracted T1-weighted spin-echo images might be able to replace the conventional standard-dose T1-weighted spin-echo images in MR imaging of the brain. 相似文献
69.
应用皮肤皱缩缝合技术行垂直切口乳房缩小整形术 总被引:3,自引:0,他引:3
目的 减少乳房缩小整形术所导致的切口瘢痕。方法 在做乳房缩小整形术时 ,在乳房下皱襞处不做切口 ,仅保留乳晕周围和乳晕下垂直切口 ,对乳房进行悬吊和塑形 ,而对乳晕下多余的皮肤和较长的皮肤切口 ,应用皮肤皱缩缝合技术进行缝合 ,利用组织的弹性 ,使其在手术后自动逐渐展平。结果 共为 13例患者实施了垂直切口的乳房缩小整形术 ,术后切口皆一期愈合 ,无血肿、感染、皮肤或乳头坏死等并发症发生 ,除 3例巨乳合并乳房严重松垂者半年后需再次对下皱襞处多余皮肤进行小的修整外 ,其余患者术后乳房和垂直切口形态满意。结论 垂直切口乳房缩小整形术设计、操作简单 ,容易掌握 ,效果恒定 ,在保证乳房缩小整形良好的乳房形态的同时 ,避免了在乳房下皱襞处的切口 ,是一种较好的乳房缩小整形术式。 相似文献
70.
股骨重建钉治疗同侧股骨颈、干骨折 总被引:16,自引:0,他引:16
目的 探讨使用股骨重建钉内固定治疗同侧股骨颈、干骨折的临床疗效、手术要点和围手术期注意事项。方法 对12例使用股骨重建钉治疗的疗效进行回顾性分析。手术采用闭合穿钉、闭合或小切口切开复位,用三维瞄准器锁定远骨折端,股骨颈保持15。前倾角置人2枚拉力螺纹钉。结果 11例获得随访,随访平均时间12.3个月(6~58个月)。远期疗效按马元璋评定标准:优5例,良4例,可2例,优良率81.8%,平均股骨颈骨折临床愈合时间5.2个月、股骨干骨折临床愈合时间6.7个月,一期骨折愈合率达到72.7%,其中3例术后10,12,15个月远骨折段骨延迟愈合,改为动力固定,4~6个月后骨折愈合。无股骨头坏死征象。结论 股骨颈骨折强调不切开复位,并争取解剖复位;股骨干骨折则常规闭合穿钉、小切口复位、有限扩髓、静力固定。股骨重建钉是目前治疗股骨干粉碎性骨折伴同侧股骨颈骨折的有效方法。 相似文献