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31.
后房型人工晶状体植入术后的超声生物显微镜观察 总被引:6,自引:2,他引:4
目的:探讨后房型人工晶状体植入术后眼前节结构的改变。确切定位人工晶状体襻的位置。观察人工晶状体襻对于周围组织的影响。方法:白内障摘除及后房型人工晶状体植入术的50名患者(50眼)于术前,术后1周及三个月进行超声生物显微镜观察。结果:术后前房深度,房角宽度押送术前显著增加。人工晶状体中囊袋内植入者36枚(72%)。睫状沟植入者6枚(12%),不对称植入者8枚(16%)。人工晶状体光学部倾斜1眼(2%)。人工晶状体襻推挤虹膜根部2眼(4%)。人工晶状体襻睫状沟侵蚀3眼(6%)。术后1周2眼(4%)眼压升高。皮质少量残留5眼(10%)。结论:囊袋内为后房型人工晶状体植入的理想位置。可保证人工晶状体的良好位置。避免人工晶状体襻对于色素膜组织的干扰及对血-房水屏蔽的损伤,从而减少并发症的发生。 相似文献
32.
Ultrasonographic (US), computed tomographic (CT), and magnetic resonance imaging (MRI) findings of a patient suffering from an amebic abscess of the liver complicated by a bronchohepatic fistula are presented. Subsequent to US, CT provided the specific diagnosis. Multiplanar MRI was valuable to directly visualize the secondary diaphragmatic rupture and the bronchohepatic fistula. 相似文献
33.
Istvn . Mrocz Kullervo Hynynen HLkon Gudbjartsson Sharon Peled Vincent Colucci Ferenc A. Jlesz 《Journal of magnetic resonance imaging : JMRI》1998,8(1):136-142
The aim of this study was to investigate a potential technique for image-guided minimally invasive neurosurgical interventions. Focused ultrasound (FUS) delivers thermal energy without an invasive probe, penetrating the dura mater, entering through the cerebrospinal fluid (CSF) space, or harming intervening brain tissue. We applied continuous on-line monitoring by MRI to demonstrate the effect of the thermal intervention on the brain tissue. For this, seven rabbits had a part of their skull removed to create access for the FUS beam into the brain through an acoustic window of 11 mm in diameter. Dura was left intact and skin was sutured. One week later, the rabbits were sonicated for 3 seconds with 21 W acoustic power, and the FUS focus was visualized with a temperature-sensitive T1-weighted MRI pulse sequence. The tissue reaction was documented over 7 days with T2-weighted images of the brain. The initial area of the central low signal intensity in the axial plane was .4 ± .3 mm2, and for the bright hyperintensity surrounding the lesion, it was 2.3 ± .6 mm2 (n = 7). In the coronal plane, the corresponding values were .4 ± .1 mm2 and 3.4 ± .9 mm2 (n = 5). The developing brain edema culminated 48 hours later and thereafter diminished during the next 5 days. Histology revealed a central necrosis in the white matter surrounded by edematous tissue with inflammatory cells. In summary, the image-guided thermal ablation technique described here produced a relatively small lesion in the white matter at the targeted location. This was accomplished without opening the dura or the need for a stereotactical device. MRI allowed on-line monitoring of the lesion setting and the deposition of thermal energy and demonstrated the tissue damage after the thermal injury. 相似文献
34.
Ultrasound for diagnosis of apophyseal injuries 总被引:1,自引:0,他引:1
D. Lazović U. Wegner G. Peters F. Gossé 《Knee surgery, sports traumatology, arthroscopy》1996,3(4):234-237
Avulsion injuries of the apophysis is a problem in young athletes. A correct diagnosis is necessary for establishing the appropriate treatment and the rehabilitation program. However, it is often difficult to distinguish between a simple muscle strain and an avulsion fracture. The X-ray examination is helpful only when an ossification center of the apophysis exists. Ultrasonography is considered the suitable diagnostic tool for these cases. From June 1988 to June 1993, 243 young athletes were seen with an anamnestic and clinically suspected apophyseal injury of the lower extremity. In all cases X-ray examination and ultrasound examination were performed. In 80 cases the diagnosis was confirmed by X-ray examination and in 97 by ultrasonography. Four criteria were defined for the sonographic examination: (a) a hypoechogenic zone, (b) increased distance to the apophysis, (c) dislocation of the apophysis, and (d) mobility of the apophysis on dynamic examination. These criteria are correlated to (a) edema, (b) lysis, (c) avulsion, and (d) unstable avulsion of the apophysis. Ultrasonography is a proven technique for the detection of apophyseal injuries. In comparison to X-ray examination, it has the advantages of no radiation exposure, early detection even without ossification center, and dynamic examination. 相似文献
35.
近年来超声波介导的基因输送技术由于其相对安全性和操作上的简单得到关注。本文对超声波导致的声致穿孔的机制,空化核的作用——增强基因输送的效率,以及细胞和在体基因输送效率作了综述,讨论了超声波介导的基因输送效率的影响因素。此方法充满希望并且载药的空泡可以作为一种新型药物载体在超声作用下实现药物的靶向输送 相似文献
36.
目的分析孕中期血清筛查数据和胎儿彩色多普勒与染色体异常之间的关系。方法对一孕中期血清产前筛查18三体风险1:10,血清Free-hCGβ异常减低(值为1.29ng/ml即0.08MOM),胎儿系统结构检查提示胎儿小于孕周,头腹围比(1.63)大于正常(1.25),上唇连续性中断延至鼻底的孕妇进行羊膜腔穿刺,抽取羊水进行细胞遗传学检查。结果羊水细胞染色体核型:69,XXY。结论中孕期妇女血清Free-hCGβ异常减低和胎儿头胸围发育不同步、胎儿唇腭裂提示胎儿染色体畸变可能,血清和超声联合筛查有助于染色体疾病的检出。 相似文献
37.
M. Eriksen 《Medical & biological engineering & computing》1987,25(2):189-194
A system for the direct measurement of the inner diameters of selected human arteriesin situ has been developed. Ultrasound pulses are emitted perdendicular to the vessel axis, and reflected from the wall material
interfaces. Improved depth resolution is achieved by using a high-frequency transducer, and by inverse filtering of the signal.
This is performed by emitting a waveform calculated beforehand to give an optimum time resolution in the received echo. Echoes
from both innerand outer surfaces of the vessel walls are discriminated, and the inter-echo time intervals can be measured
with an accuracy of 33ns, corresponding to approximately 26μm. By repeating the measurements through the cardiac cycle, the
diameter variations can be accurately described. 相似文献
38.
Ultrasonographic assessment of human skeletal muscle size 总被引:7,自引:0,他引:7
The measurement of human muscle size is essential when assessing the effects of training, disuse and ageing. The considered gold standard for cross-sectional area measurements of muscle size is magnetic resonance imaging (MRI). However, MRI is costly and often inaccessible. The aim of the present study was to test the reproducibility and validity of a more accessible alternative method using ultrasonography (ULT). We examined the cross-sectional areas in the vastus lateralis muscle of six individuals. Axial-plane ULT scans were taken at given levels along the entire muscle length. The ULT scanning was repeated on different days (reliability) and validated against MRI-based measurements. Mean intraclass correlation coefficients were 0.998 for the reliability of ULT and 0.999 for the validity of ULT against MRI. The coefficient of variation values for cross-sectional area measurements assessed by six different experimenters were 2.1% and 0.8% for images obtained with ULT and MRI, respectively. The ULT method is a valid and reliable alternative tool for assessing cross-sectional areas of large individual human muscles. The present findings justify the application of the ULT method for the detection of changes throughout large muscles in response to training, disuse or as a consequence of sarcopenia. 相似文献
39.
Saijo Y Ohashi T Sasaki H Sato M Jorgensen CS Nitta S 《Annals of biomedical engineering》2001,29(12):1048-1053
Scanning acoustic microscopy (SAM) was equipped to assess the acoustic properties of normal and atherosclerotic coronary arteries. The SAM image in the atherosclerotic lesion clearly demonstrated that the sound speed was higher than that in the normal intima, and that the variation of elasticity was found within the fibrous cap of the plaque. Young's elastic modulus of each region was calculated and the finite element analysis was applied to derive the stress distribution in these arterial walls. In a case of normal coronary artery, the stress was dominant in the intima and the distribution was rather homogeneous and in a case of atherosclerosis, high stress was concentrated to the relatively soft lesion in the fibrous cap overlying lipid pool. SAM provides information on the physical properties, which cannot be obtained by the optical microscope. The results would help in understanding the pathological features of atherosclerosis. © 2001 Biomedical Engineering Society.
PAC01: 8764-t, 8763Df, 8719Xx, 8719Rr 相似文献
40.
目的 用Logistic多因素非条件回归分析,建立超声筛查胎儿发育异常回归模型。方法对影响胎儿发育异常的各个因素进行非条件Logistic回归分析,计算标准偏回归系数、0R值等。结果共有7个因素进入方程,从各影响因素的标准偏回归系及OR值大小分析,以股骨、孕妇年龄、羊水对回归模型影响较大。结论胎儿发育异常与多种因素有关,股骨短小的孕妇应作为超声重点监测对象。 相似文献