超声造影诊断肝孤立性坏死结节的价值

目的:探讨超声造影诊断肝孤立性坏死结节的价值。材料和方法:回顾分析了12例肝孤立性坏死结节的超声造影表现。结果:12例病灶造影动脉期、门脉期、实质期均无增强,呈边界清晰的造影剂充盈缺损区。结论:超声造影对诊断肝孤立性坏死结节具有较高的价值。目的:探讨超声造影诊断肝孤立性坏死结节的价值。材料和方法:回顾分析了12例肝孤立性坏死结节的超声造影表现。结果:12例病灶造影动脉期、门脉期、实质期均无增强,呈边界清晰的造影剂充盈缺损区。结论:超声造影对诊断肝孤立性坏死结节具有较高的价值。     

超声引导下经皮经肝胆囊/胆管置管引流术在肝胆系疾病中的临床应用

目的探讨超声引导下经皮经肝胆囊置管引流术(percutaneous transhepatic gallbladder drainage，PTGD)／经皮经肝胆管置管引流术(percutaneous transhepatic bile duct drainage，PTBD)在肝胆系疾病中的应用价值。方法从2000年12月至2003年12月在超声引导下对60例患者施行PTGD／PTBD68例次，其中急性化脓性胆囊炎15例，急性重症胆管炎8例，各种恶性梗阻性黄疸37例。结果15例急性化脓性胆囊炎患者行PTGD术，14例成功，1例失败而中转手术。37例恶性梗阻性黄疸患者共行45例次PTBD术，42次置管成功，3例失败，其中2例中转手术，1例放弃治疗；14例择期行胆管癌切除术或姑息内引流术，8例在x线透视下放置胆道支撑架，15例患者长期带管，最长存活者已超过2年，平均9个月。8例急性重症胆管炎6例成功，1例因引流不畅而中转手术，1例死于多器官功能衰竭。并发症包括：胆漏2例，出血3例，门静脉胆管瘘1例，引流管脱出或阻塞7例。结论超声引导下PTGD／PTBD是胆道引流的有效方法，具有创伤小，操作简便、准确、安全，并发症少等优点，在肝胆系疾病，尤其是急性胆囊炎具有较大的临床应用价值。     

对116例异位妊娠的腹部超声诊断分析

目的：探讨腹部超声对异位妊娠诊断价值。方法：用腹部超声对116例异住妊娠进行手术及病理检查结果进行分析。结果：114例经手术及病理证实诊断为异位妊娠，诊断符合率为97．68％，误诊率2．32％。结论：腹部超声检查异住妊娠可给临床提供准确率很高的诊断依据，它具有简便、直观、迅速、敏感性高、无损伤及易于重复等优点，所以腹部超声应作为异位妊娠诊断的首选方法。     

Transvaginal ultrasound and diagnostic hysteroscopy as a predictor of endometrial polyps: risk factors for premalignancy and malignancy

The aim of this study is to assess accuracy of transvaginal ultrasound (TVUS) and diagnostic hysteroscopy in diagnosing endometrial polyps and to determine premalignancy and malignancy rates in asymptomatic women. The study was designed to retrospectively analyze 438 women who underwent operative hysteroscopy in a day-care unit when endometrial polyp was suspected after TVUS and diagnostic hysteroscopy. Multivariate logistic regression modeling showed effects of age, previous breast cancer with tamoxifen treatment, and menopause with or without bleeding on pathologic results. The results indicate that positive predictive value of TVUS with diagnostic hysteroscopy was 79.9%. Premalignancy or malignancy occurred in 3.2% and was significantly related to menopause with abnormal bleeding (P < 0.001), which carried a 20-fold higher risk of pathology than any other group. Age was also a risk factor. It was concluded that TVUS with diagnostic hysteroscopy reliably evaluates endometrial polyps. The low incidence of endometrial tumors in asymptomatic (especially premenopausal) women suggests that their operative evaluation may not be cost effective. Larger studies are needed to support this tentative conclusion.     

Postmenopausal Women With Colles'' Fracture Have Lower Values of Bone Mineral Density Than Controls as Measured by Quantitative Ultrasound and Densitometry

Measurement of ultrasonographic parameters provides information concerning not only bone density but also bone architecture. We investigated the usefulness of ultrasonographic parameters and bone mineral density (BMD) to evaluate the probability of Colles' fracture. Two-hundred eighty-nine postmenopausal women (62.3 +/- 8.7 yr) with (n = 76) and without (n = 213) Colles' fracture were studied. BMD of lumbar spine and proximal femur was evaluated in all women by dual-energy X-ray absorptiometry (DXA) and speed of sound (SOS), broadband ultrasound attenuation (BUA), and stiffness in the calcaneus were measured by a Sahara ultrasonometer (Hologic). Patients suffering from Colles' fracture had lower values of BMD adjusted by height at the lumbar spine, L2-L4 (0.797 g/cm2 vs 0.860 g/cm2), femoral neck (0.685 g/cm2 vs 0.712 g/cm2 ), SOS (1518 m/sg vs 1525 m/sg), and stiffness (74.6 vs 77.7) (p < 0.05). Nevertheless, BUA values were similar in both groups. After stepwise logistic regression analysis, the area found under receiver operating characteristic (ROC) curves was 0.60 for L2L4 and 0.63 for a formula combining L2L4 and height. Our data suggest that patients suffering from Colles' fracture have lower values of BMD by DXA, SOS, and stiffness. However, the ability of these techniques to discriminate is low because the values for the area under ROC curve are 0.60 for L2-L4 and 0.63 for a formula derived of the combination of L2-L4 and height.     

Estimation of average flow in ungated 3D phase contrast angiograms

Three dimensional (3D) phase contrast angiograms contain velocity data, which is discarded after the reconstruction of the projections. In extension to earlier work on velocity quantification with ungated 2D phase data, this paper shows that a useful estimate of the average velocity and flow rate can be extracted from ungated 3D phase contrast angiograms. Simulations and experiments in a phantom and in vivo were performed. For pulsatile flow and strong spin saturation, an over-estimation of the flow rate at the net in-flow end of the imaging volume and underestimation at the net out-flow end was observed. Imaging at lower RF tip angles yielded flow rates close to the correct value within the entire imaging volume. In contrast to ungated 2D experiments, the flow rates determined by repeated 3D experiments showed no variation.     

Development of neurochemical separation of ON and OFF channels at retinal ganglion cells

Anatomical and physiological segregation of neurons into ON (brightening detector) and OFF (darkening detector) channels in the retina and subsequent visual system ensure the high sensitivity required for contrast detection and spatial discrimination. This segregation is finest at the visual axis. Neurochemically, ON and OFF ganglion cells at the visual axis seem to be distinguished by different inhibitory transmitters but not excitatory transmitters. Microiontophoretic studies of inhibitory transmitters on the retinal ganglion cells in kittens and adult cats suggest that this neurochemical distinction is poor in immature ganglion cells at the visual axis. Initially both ON and OFF cells seem to be supplied by GABAergic, glycinergic, and catecholaminergic amacrine cells, but in adults, ON cells remain supplied only by GABAergic amacrines, while OFF cells are supplied by glycinergic amacrines. Postnatal elimination of multiple inputs and strengthening of the appropriate inputs, as seen in the central nervous system, also seem to occur at the retinal neurotransmitter synapses during development.     

Ultrasound Biomicroscopic Dark Room Provocative Test

Purpose : To compare the clinical application value of Ultrasound biomicrsocpic dark room provocative test with the traditional dark room test in screening primary angle closure glaucoma (PACG).Methods: 22 eyes with PACG in prodromal stage and 30 eyes with deep anterior chamber and wide angle of 15 normal persons were observed in this trail. All 52 eyes were performed traditional dark room provocative test and ultrasound biomicorosopic darkroom test respectively. With different positive diagnostic criteria, the sensitivity of the two methods were compared using chi-squared analysis.Results : After staying in the dark room for 2 hours, In case group, IOP in 10 of 22 eyes rose more than 1. 07kPa(1kPa = 7.5mmHg), in 12 eyes less than 1.07kPa or had no changes; appositional angle closure were found by Goldmann gonioscopy in 8 eyes : 3 eyes in two quadrants, 5 eyes in more than two quadrants; the appositional angle closure was found by UBM in 15 eyes; 3 eyes in one quadrants, 5 eyes in two quadrants, 7 eyes     

产科诊断剂量超声波对培养细胞影响的实验研究

采用模拟在人体中使用的实测超声剂量，对体外培养的Ｌ－９２９株细胞进行辐照，通过细胞回复能力试验，观察回复前后的细胞增殖与抑制。对体外培养的人胚肺纤维细胞经１次及５次辐照，观察了ＤＮＡ及细胞核面积的影响。并通过电镜观察了细胞超微结构的变化。上述实验结果，均提示经辐照后细胞有增殖趋向     

血管内支架模型及离体血管经腔内超声三维重建的实验研究

我们自制了16个不同形状和大小的金属支架模型，置入人造血管腔中，并采用高体正常血管8条（犬腹主动脉4条，人冠状动脉4条）进行经血管腔内超声显像（IVUS）的体元模型三维重建（3DR）研究。结果显示，该技术能真实地再现支架在管腔内的形态、支架与管壁之间的间隙及离体正常血管的管腔及管壁形态，经提取后重建的支架模型与实物非常相似。经3DR测得的支架及血管腔内径与实测值均高度相关（r分别为0.96和0.99，p＜0．001）。支架与管壁之间空隙的3DR测值与实测值也高度相关（r=0.97，p＜r.0.01）。