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81.
Pulsed ultrasonic Doppler velocimetry (20 MHz) (PUDVM) has evolved considerably in the last 10 years. Engineering development has resulted in a computer-controlled vessel-scanning instrument whose backscattered frequency shift spectra are analyzed using fast Fourier transforms (FFT). Benchtop and theoretic studies indicate accurate (error less than 5%) velocity and volumetric flow rate measurements in vessels with a lumen diameter as small as 1.2 mm. Clinical application of the PUDVM has provided transcutaneous measurements of blood flow variables in normal human digital arteries. Experimental application to arteries 1.0-1.5 mm has provided information on the hemodynamic effects of topical vasodilators, standard microarteriorrhaphy, variations in microvascular technique, interpositional grafts, and early wound repair. With improving computer capabilities and technical modifications, the PUDVM will be an increasingly important tool in clinical and experimental microsurgery. 相似文献
82.
A case of solitary extramedullary plasmacytoma of the testis is presented demonstrating the appearances on ultrasound. The clinical implications of this diagnosis are discussed. 相似文献
83.
84.
采用流室定量研究阶跃切应力对内皮细胞释放前列环素(pGI_2)的影响。对流室中的内皮细胞连续100分钟施加1、10、20dyne/cm ̄2的阶跃剪切应力,用放免法测流室的8个时间段流出液的6-keto-PGFi_(1a)。绘出切应力刺激内皮细胞释放PGI_2的曲线。结果表明:未施加切应力时,内皮细胞释放PGI_2的量在检测限以下,施加切应力后,PGI_2释放速率很快达极大值,且又在数分钟内减小.施加阶跃切应力越大,PGI_2释放速率曲线峰值越高,但衰减也越快,在80~100分钟时间内的前列环素释放速率平均值也越大。由此提示,在活体中血液流变学因素一血流切应力对血管内皮细胞释放前列环素有促进作用。 相似文献
85.
超声引导下注射皮质类固醇治疗狭窄性腱鞘炎 总被引:1,自引:0,他引:1
目的 探讨超声引导下注射皮质类固醇治疗狭窄性腱鞘炎的方法及效果。方法 38例狭窄性腱鞘炎患者,按药物注射方法的不同随机分成2组。治疗组(21例)在10-MHz超声引导下向腱鞘内腱周间隙内穿刺注射醋酸强的松龙0.6 ml,对照组(17例)采用闭合穿刺法注射等量药物。注射前及随访时(注射后3周)测定疼痛强度视觉类比评分(Visual analogue score,VAS)。结果 随访时疼痛消失率治疗组为81%、对照组为53%,VAS下降值治疗组为[(6.8±1.9)x±s,下同]对照组为(5.1±3.0)。结论超声引导下将针尖穿刺于腱鞘内腱周间隙的操作简单、准确并可实时观察药物的分布,是治疗狭窄性腱鞘炎的较好方法。 相似文献
86.
A mesenteric cyst with milk of calcium in an adult patient is presented. Preoperative evaluation included plain film, ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI). To our knowledge, the presence of milk of calcium in a mesenteric cyst has not been previously described. 相似文献
87.
H. Brändström P. Gerdhem F. Stiger K. J. Obrant H. Melhus Ö. Ljunggren A. Kindmark K. Åkesson 《Calcified tissue international》2003,74(1):18-24
Osteoprotegerin (OPG), a secreted member of the tumor necrosis factor receptor family, is a potent inhibitor of osteoclast activation and differentiation. In animal models OPG prevents bone loss, and in humans bone resorption can be reduced by injections of OPG. OPG may also play a role in cardiovascular disease since mice lacking the OPG gene display arterial calcification. In a screening effort of the OPG gene, we recently discovered a single nucleotide polymorphism in the promoter region of OPG (T950C), and reported an association with vascular morphology and function in 59 healthy individuals. Due to the pronounced effect of OPG on bone turnover, the present study was conducted to investigate whether OPG polymorphisms are also associated with bone mineral density or with fracture. The relationship between single nucleotide polymorphisms in the promoter region of OPG (T950C) and the first intron (C1217T), and bone mineral density, measured by DXA in the hip or spine or ultrasound of the heel, was investigated in the Malmö OPRA-study of 1044 women, all 75 years old. The possible relation to fracture incidence was also analyzed. Among the 858 and 864 individuals respectively, genotyped, no significant associations between the investigated single nucleotide polymorphisms and bone mineral density measurements (T950C P = 0.50–0.64, C1217T P = 0.51–1.00), quantitative ultrasound measurements of the calcaneus, or fractures (T950C P = 0.61–0.66, C1217T P = 0.14–0.33) were found. Thus, our results show that polymorphisms in the OPG gene, one of which has previously been found to be associated with cardiovascular morphology and function, are not associated with bone mineral density in elderly Swedish women. 相似文献
88.
89.
B C Goss K P McGee E C Ehman A Manduca R L Ehman 《Magnetic resonance in medicine》2006,56(5):1060-1066
Magnetic resonance elastography (MRE) is a phase-contrast technique that can spatially map shear stiffness within tissue-like materials. To date, however, MRE of the lung has been too technically challenging-primarily because of signal-to-noise ratio (SNR) limitations and phase instability. We describe an approach in which shear wave propagation is not encoded into the phase of the MR signal of a material, but rather from the signal arising from a polarized noble gas encapsulated within. To determine the feasibility of the approach, three experiments were performed. First, to establish whether shear wave propagation within lung parenchyma can be visualized with phase-contrast MR techniques, MRE was performed on excised porcine lungs inflated with room air. Second, a phantom consisting of open-cell foam filled with thermally polarized (3)He gas was imaged with MRE to determine whether shear wave propagation can be encoded by the gas. Third, preliminary evidence of the feasibility of MRE in vivo was obtained by using a longitudinal driver on the chest of a normal volunteer to generate shear waves in the lung. The results suggest that MRE in combination with hyperpolarized noble gases is potentially useful for noninvasively assessing the regional elastic properties of lung parenchyma, and merits further investigation. 相似文献
90.
目的分析并比较NE系列的两种冲击波源碎石机治疗输尿管结石的疗效、碎石时的疼痛程度、碎石时间及副作用。方法回顾性分析应用NE-IV型液电冲击波源碎石机治疗输尿管结石患者1290例及应用NE-VB型电磁冲击波源碎石机治疗输尿管结石患者1196例的临床资料,并进行疗效、碎石时间、碎石时的疼痛程度及副作用的比较。结果应用电磁冲击波源碎石机治疗输尿管上段结石患者的总有效率为85.4%,治疗时间23~60min,平均(35.3±5.7)min;输尿管下段结石患者的总有效率为94.6%,治疗时间3~60min,平均(30.5±6.1)min。碎石时患者的疼痛感觉轻。液电冲击波源碎石机治疗的输尿管上段结石患者的总有效率为75.7%,治疗时间25~110min,平均(38.0±9.8)min;输尿管下段结石为85.7%,治疗时间4~90min,平均(35.8±7.7)min。碎石时患者的疼痛感觉明显。此外,肾绞痛、血尿、恶心、呕吐、皮肤瘀斑等副作用明显高于电磁冲击波源碎石机治疗组。结论电磁冲击波源碎石机治疗输尿管结石疗效优于液电冲击波源碎石机,而且更安全、有效、痛苦小。 相似文献