In vivo comparison of two through-plane MR velocity mapping methods: Fast fourier encoding and phase mapping

Magnetic resonance imaging maps of velocity were acquired with a 1.5-T system in 10 subjects in a plane perpendicular to the main pulmonary artery. Velocity images were successively acquired with a method developed from Fourier-encoding velocity imaging (FEVI) principles with eight gradient steps and one excitation, and with two-point phase-subtraction mapping. Reconstruction in FEVI was implemented by zero-filling interpolation around the eight gradient steps and then around the four central steps. The methods were compared by using estimates of noise in velocity measurements based on the difference between the experimental map and a smooth fitted map. For the same acquisition time, FEVI with four encoding steps was more precise in velocity measurements than phase mapping. Precision was further increased by the use of eight encoding steps, but acquisition time was doubled.     

日本的生活垃圾收费及减量效果分析——"日野模式"考察

介绍了东京都日野市确立生活垃圾收费标准的方式及为推行这一政策所采取的相关举措,分析了收费前后的垃圾减量效果及居民的环境意识变化,提出了对我国探索城市生活垃圾收费改革的启示.     

闭合复位经皮螺钉内固定治疗跖跗关节损伤

目的探讨应用闭合复位经皮螺钉内固定治疗跖跗关节损伤的临床疗效。方法自2003年1月～2005年6月应用闭合复位经皮螺钉内固定治疗跖跗关节损伤26例。按照Myerson分类:中间柱损伤13例,内侧、中间柱合并损伤7例,内侧、中间、外侧柱三柱损伤6例。结果本组切口均一期愈合,平均手术时间为40min(30～70min),切口长度平均为5mm;所有患者获平均11.4个月(6～17个月)随访,根据美国足踝骨科协会(AOFAS)评分平均为87分,患者术后平均5.3个月(3～11个月)恢复正常生活。结论闭合复位经皮螺钉内固定手术创伤小,软组织并发症低,能有效治疗跖跗关节复合体损伤;中间柱复位并沿Lisfranc韧带方向插入螺钉内固定是重建跖跗关节复合体稳定性的关键。     

Restricted field of view magnetic resonance imaging of a dynamic time series.

A restricted field of view (rFOV) approach for imaging a dynamic time series of volumes of limited spatial extent within a larger subject is described. The shorter readout with rFOV-MRI can be exploited to either limit image artifacts or increase spatial resolution. To accomplish rFOV imaging of a multislice volume for a dynamic series, an outer volume suppression (OVS) preparation that saturates signal external to a cylinder through the subject is followed by slice-selective excitation and a spiral readout. The pass- and stopband efficiencies of the OVS in an agar gel phantom were 97% (+/-1.5%) and 3% (+/-1%), respectively. Profiles of the temporal signal-to-noise ratio (SNR) were measured in a phantom and an adult brain. The rFOV sequence reduced distortions from off-resonance signal and T2*-induced blurring compared to a conventional sequence. Sequence utility is demonstrated for high-resolution rFOV functional MRI (fMRI) in the visual cortex. The rFOV sequence may prove to be useful for other multislice dynamic and high-resolution imaging applications.     

桡骨颈骨折经皮撬拨复位的远期疗效

用经皮撬拨复位治疗桡骨颈骨折56例,其中复位良好46例,较好6例和不良4例;经3年7个月平均随访,复位良好和较好的44例中,后期疗效良好32例,较好11例和一般1例。骨折解剖复位、撬拨复位的手术损伤轻和石膏固定时间较短是后期疗效满意的关键。成人桡骨颈骨折伴肘内侧副韧带严重损伤比儿童多见,但儿童桡骨颈骨折严重倾斜移位和完全移位比成人多见,后期疗效更满意。     

硝基化合物还原、氢化的研究 Ⅳ.用Fe~(3+)催化转移氢化3,3′-二硝基-4,4′-二氨基二苯醚

以Fe~(3+)代替Pd-C和Raney Ni为催化剂、水合肼为供氢体、3,3′-二硝基-4,4′-二氨基二苯醚为受氢体、甲醇为溶剂,进行催化转移氢化反应,产物3,3′,4,4′-四氨基二苯醚(TADPO)质量好,得率可达80%。此外,还对反应温度、时间、以及水合肼、催化剂、溶剂用量,水合肼浓度、催化剂重复使用等影响因素进行了研究,获得了较佳工艺条件。本法制得的TADPO与均苯四甲酸二酐缩聚可制得性能良好的聚眯唑吡咙。     

3—氯—4—氟苯胺的生产与研究概况

评述了3-氯-4-氟苯胺的实验室研究和工业生产现状,特别对氯化、硝化、氟化和还原等反应中间体的制备及其质量作了分析。     

AO苜蓿叶形支撑钢板治疗Pilon骨折

目的总结使用AO苜蓿叶形钢板治疗Pilon骨折的经验。方法分析我科自1996年3月-2001年6月用该方法治疗的23例病人的治疗效果：按Ruedi-Allgower分型：其中Ⅱ型18例，Ⅲ型5例，均采用切开复位，AO苜蓿叶形钢板内固定术。结果治疗后，临床疗效优良率82．6％，其中Ⅱ型达88．8％，Ⅲ型达60％。结论AO苜蓿叶形钢板治疗Pilon骨折，具有骨折稳定性可靠，有利于骨折愈合和早期关节活动的优点，Ⅲ型骨折的治疗方法有待进一步探讨。     

撬拨复位空心钉内固定治疗跟骨舌状骨折

目的探讨撬拨复位空心钉内固定治疗跟骨舌状骨折的临床意义。方法对31例39侧跟骨舌状骨折，行闭合撬拨复位空心钉内固定术。结果全部病例得到随访，平均随访22个月，根据Maryland评分系统进行术后功能评价。优18足，良16足，可3足，差2足，优良率87．2％。结论跟骨舌状骨折行撬拨复位空心钉内固定可以较好复位，固定可靠，早期开始功能锻炼，疗效满意。     

闭合复位经皮穿针治疗移位的肱骨外科颈骨折

目的总结闭合复位经皮穿针治疗移位的肱骨外科颈骨折的方法及结果。方法2001年1月～2002年12月,采用闭合复位、经皮穿针治疗移位的肱骨外科颈骨折46例,仅对其中随访资料完整的34例患者进行分析。结果34例获得22个月(10～34个月)的平均随访。采用Constant-Murley评分方法,平均Constant-Murley绝对值为92分(76～100分),优良占86%(29/34),可占14%(5/34),无差病例。所有骨折在术后6～8周愈合,无固定失效,未出现肱骨头坏死病例。结论闭合复位经皮穿针治疗移位的肱骨外科颈骨折手术时间短、软组织损伤小、固定可靠,术后可早期功能锻炼,取针简便。