基于直肠超声图像分析引导下的经会阴前列腺穿刺活检在前列腺癌诊断中应用

目的:探讨经直肠超声引导下经会阴前列腺穿刺活检对于前列腺癌诊断的价值。方法:通过9+X穿刺方法,对82例临床拟诊前列腺癌的患者进行经直肠超声引导下经会阴前列腺穿刺活检,对穿刺结果进行分析。结果:全部患者均活检成功,前列腺癌的阳性率为25.6%(21/82),穿刺并发症轻微。结论:经直肠超声引导下经会阴前列腺穿刺活检相对阳性率更高,并发症相对较少、较轻,适应范围更广,必将有更广阔的应用前景。     

肺隐球菌病18例临床分析

目的探讨肺隐球菌病的临床特征,以提高对本病的认识。方法回顾性分析我院2001年1月-2008年8月经病理确诊为肺隐球菌病住院患者临床资料。结果本组肺隐球菌病以中青年男性为主,既往均无基础疾患。主要临床症状有咳嗽、咳痰、发热,病变影像学以肿块结节型为主,经CT引导下经皮肺穿刺活检证实7例,手术证实11例,病理诊断前误诊率达100%。11例经外科手术切除,其余应用抗真菌药物治疗,均取得较好疗效。结论肺隐球菌病多发生于中青年男性,临床表现无特异性,影像学改变以肿块结节型为主,误诊率高,确诊有赖于病理,对难以明确诊断者应尽早行病理检查。     

二维及三维超声成像在先天性子宫畸形诊断中的应用

目的:分析二维及三维超声成像在先天性子宫畸形诊断中的临床应用。方法:二维超声常规检查时,对可疑有先天性子宫畸形的病例进行经阴道三维超声扫查,并联合二维超声检查结果综合分析。结果:经阴道二维超声成像获得明确子宫畸形诊断的41例,经阴道三维超声成像获得明确子宫畸形诊断的61例,二者联合获得较明确子宫畸形诊断的64例。结论:二维及三维超声成像联合能够得到子宫外形轮廓和子宫腔准确、全面的信息,较准确地诊断先天性子宫畸形,特别是三维超声冠状切面成像在子宫畸形的分类、鉴别诊断及指导临床治疗中,起着非常重要的作用。     

经尿道钬激光前列腺切除术护理

1资料与方法1.1临床资料我科2004年至今共收治76例患者,年龄56岁至85岁,平均66.27岁。有尿频、夜尿增多、进行性排尿、尿潴留等症状;经前列腺特异抗原(PSA)、直肠指检(DRE)、国际前列腺症状评分(IPSS)、生活质量评分(QOLS)及尿动力学检查明确诊断为BPH。其中15例有尿潴留史。1.     

超声引导经阴道穿刺治疗输卵管积水

目的探讨超声引导经阴道穿刺治疗输卵管积水的临床效果。方法对61例输卵管积水患者行超声引导经阴道穿刺抽液及无水乙醇凝固治疗,随访3～12个月。结果61例患者中58例成功完成了液体抽吸及无水乙醇凝固治疗。术后3个月随访53例,其中治愈47例（88．7％）,好转2例（3．8％）,无效4例（7．5％）,总有效率为92．5％。术后12个月随访41例,其中治愈36例（87．8％）,好转2例（4．9％）,无效3例（7．3％）,总有效率为92．7％。所有囊内液细胞学检测均未发现癌细胞。结论超声引导经阴道穿刺治疗输卵管积水技术操作简单、疗效可靠。     

SAM扫描器件芯/焊结合空洞的失效分析

超声无损检测是70种无损探伤技术的最热点。扫描声学显微镜(SAM)的原理是声阻抗成像,要求缺陷尺度大于超声波的波长。结合SAM技术中的A-扫描波形分析和C-扫描特征成像,针对由封装引入的分层和空洞缺陷进行失效分析。研究发现:分层定位的关键是A-扫描波形分析中对各界面处反射波的时间位置的判断;基于分层定位的芯/焊结合空洞缺陷的判别,关键是C-扫描图像中灰阶色带的区分(反射率差值)。     

Creutzfeldt-Jakob病二例电镜观察

本实验用透射电镜观察了二例Ｃｒｅｕｔｚｆｅｌｄｔ－Ｊａｋｏｂ病（ＣＪＤ）的尸检及活检脑组织。其中一例为死后６天尸检脑组织,电镜下可见神经元及神经胶质细胞明显变性,核染色质块状凝集,核碎裂,可见细胞碎片。另一例为穿刺活检脑组织,因取材过少光镜病理检查只发现脑组织水肿,不能明确诊断,电镜观察二例均少见神经元,神经胶质细胞多见且变性,最突出的表现为脑组织的海绵状界膜空泡变性,有髓神经纤维髓鞘解离并有部分溶解,轴索溶解消失并呈空泡样变性。本实验表明：对临床上表现为进行性痴呆,脑电图广泛异常的病人的组织活检,送检组织过少,一般病理检查不能明确诊断时,电镜检查具有重要意义,即使是死亡６天后的尸检仍可为ＣＪＤ这种疑难和罕见病例的确诊提供有力的证据。     

1例垂体肉芽肿伴出血的护理

目的：探讨垂体肉芽肿的临床特点与护理。方法：报告1例病人的临床资料,并护理。结果：患者以头痛和视力障碍起病,头颅MRI提示鞍内占位性病灶,信号不均匀,视交叉明显受压上抬,手术发现病灶有出血,病理证实为垂体肉芽肿。结论：垂体肉芽肿非常罕见,临床诊断困难,常经病理确诊。术后激素治疗,严密监测病情变化及生命体征,有效护理对于改善预后意义重大。     

双波长光学相干层析成像

组建了具有980nm和1300nm两个波长光源的光学相干层析(OCT)成像系统。利用此系统,分别在两个波长、不同光源功率下,对新鲜猪肉组织进行OCT成像。比较了同一波长、不同功率和不同波长、同一功率下的OCT图像,并比较了同一波长、不同功率和不同波长、同一功率下OCT信号强度随深度变化的曲线。对曲线进行线性拟合,分析了两个波长下生物组织散射系数的变化规律。发现提高光源功率会使探测深度有限提高,而探测深度会随波长增大而增加,并分析了波长变化对OCT系统各参数的影响和进行对比的图像产生差异的原因。     

全脑CT灌注成像在邻近大血管颅内肿瘤中的临床应用

目的探讨全脑CT灌注(WBCTP)成像在邻近大血管颅内肿瘤中的临床应用价值。方法对40例经手术病理证实为邻近大血管颅内肿瘤患者行WBCTP检查,WBCTP检查获得达峰时间(TTP)、平均通过时间(MTT)、脑血流量(CBF)、脑血容量(CBV)参数的三维灌注图,同时获得动态CT血管成像(4D-CTA)图像。三维CT血管成像(3D-CTA)图像包括容积再现(VR)图像,最大密度投影(MIP)图像,和通过后处理重建的肿瘤与3D-CTA的融合图像。分析颅内肿瘤患者的CTP和CTA表现。结果所有WBCTP图像均能满足评价标准,在三维灌注图上确定异常灌注区。脑膜瘤(n=20)与胶质瘤(n=18)的CBF和CBV值比较差异有统计学意义(P﹤0.05)。有35例患者的CTA图能找到供血动脉和引流静脉。23例肿瘤毗邻邻近大动脉,13例肿瘤毗邻邻近静脉窦,4例患者同时累及大动脉及静脉窦。大动脉受压移位有20例,被肿瘤包裹7例,静脉窦被受压移位有12例,上矢状窦受侵并致管腔变窄5例。结论WBCTP可以实现对邻近大血管颅内肿瘤的全面评价,对颅内肿瘤的诊断及评价肿瘤与周围大血管的关系有重要价值,从而指导临床治疗。     

Contrast-ultrasound diffusion imaging for localization of prostate cancer

Prostate cancer is the most prevalent form of cancer in western men. An accurate early localization of prostate cancer, permitting efficient use of modern focal therapies, is currently hampered by a lack of imaging methods. Several methods have aimed at detecting microvascular changes associated with prostate cancer with limited success by quantitative imaging of blood perfusion. Differently, we propose contrast-ultrasound diffusion imaging, based on the hypothesis that the complexity of microvascular changes is better reflected by diffusion than by perfusion characteristics. Quantification of local, intravascular diffusion is performed after transrectal ultrasound imaging of an intravenously injected ultrasound contrast agent bolus. Indicator dilution curves are measured with the ultrasound scanner resolution and fitted by a modified local density random walk model, which, being a solution of the convective diffusion equation, enables the estimation of a local, diffusion-related parameter. Diffusion parametric images obtained from five datasets of four patients were compared with histology data on a pixel basis. The resulting receiver operating characteristic (curve area = 0.91) was superior to that of any perfusion-related parameter proposed in the literature. Contrast-ultrasound diffusion imaging seems therefore to be a promising method for prostate cancer localization, encouraging further research to assess the clinical reliability.     

Three-dimensional ultrasound imaging systems for prostate cancerdiagnosis and treatment

3D ultrasound imaging system for imaging the prostate can be interfaced to any conventional ultrasound machine, and can accommodate side-firing transrectal ultrasound transducers. After acquiring a series of 2D ultrasound images, a 3D image is reconstructed. The 3D image is available to the physician, allowing the prostate to be viewed interactively in multiple simultaneous planes, allowing better visualization of its internal architecture. This approach allows the physician to record and view the whole prostate in successive examinations, making 3D TRUS well-suited to performing prospective or follow-up studies. The results indicate that 3D ultrasound imaging of the prostate has great potential as a tool for the diagnosis and follow-up of prostate disease     

Pubic arch detection in transrectal ultrasound guided prostatecancer therapy

New biopsy techniques, increased life expectancy, and prostate-specific antigen (PSA) screening have contributed to an increase in the reported incidence of prostate cancer. Among several treatment options available to the patients, transperineal prostate brachytherapy has emerged as a medically successful, cost-effective outpatient procedure for treating localized prostate cancer. Transperineal prostate brachytherapy employs transrectal ultrasound (TRUS) as the primary imaging modality to accurately preplan and subsequently execute the placement of radioactive seeds into the prostate. Under TRUS guidance, a needle (preloaded with radioactive seeds) is inserted through a template guide, through the perineum and into a predetermined prostate target. The pubic arch, formed by the central union of pelvic bones, is a potential barrier to the passage of these needles in the prostate. A critical aspect, therefore, in the planning and execution of the brachytherapy procedure is the accurate assessment of pubic arch interference (PAI) in relation to the prostate. Traditionally, the evaluation of PAI has involved computed tomography correlate scanning or crude subjective evaluations. In this paper, the authors describe a new method of assessing PAI by detecting the pubic arch via image processing on the TRUS images. The PAI detection (PAID) algorithm first uses a technique known as sticks to selectively enhance the contrast of linear features in ultrasound images. Next, the enhanced image is thresholded via percentile thresholding. Finally, the authors fit a parabola (a model for the pubic arch) recursively to the thresholded image. Their evaluation result from 15 cases indicates that the algorithm can successfully detect the pubic arch with 90% accuracy. Based on this study, the authors believe that detecting the pubic arch and assessing PAI can be done practically and more accurately in the clinical setting using TRUS rather than the current available methods     

Segmentation of prostate boundaries from ultrasound images using statistical shape model

This paper presents a statistical shape model for the automatic prostate segmentation in transrectal ultrasound images. A Gabor filter bank is first used to characterize the prostate boundaries in ultrasound images in both multiple scales and multiple orientations. The Gabor features are further reconstructed to be invariant to the rotation of the ultrasound probe and incorporated in the prostate model as image attributes for guiding the deformable segmentation. A hierarchical deformation strategy is then employed, in which the model adaptively focuses on the similarity of different Gabor features at different deformation stages using a multiresolution technique, i.e., coarse features first and fine features later. A number of successful experiments validate the algorithm.     

Modelling prostate motion for data fusion during image-guided interventions

There is growing clinical demand for image registration techniques that allow multimodal data fusion for accurate targeting of needle biopsy and ablative prostate cancer treatments. However, during procedures where transrectal ultrasound (TRUS) guidance is used, substantial gland deformation can occur due to TRUS probe pressure. In this paper, the ability of a statistical shape/motion model, trained using finite element simulations, to predict and compensate for this source of motion is investigated. Three-dimensional ultrasound images acquired on five patient prostates, before and after TRUS-probe-induced deformation, were registered using a nonrigid, surface-based method, and the accuracy of different deformation models compared. Registration using a statistical motion model was found to outperform alternative elastic deformation methods in terms of accuracy and robustness, and required substantially fewer target surface points to achieve a successful registration. The mean final target registration error (based on anatomical landmarks) using this method was 1.8 mm. We conclude that a statistical model of prostate deformation provides an accurate, rapid and robust means of predicting prostate deformation from sparse surface data, and is therefore well-suited to a number of interventional applications where there is a need for deformation compensation.     

Edge-guided boundary delineation in prostate ultrasound images

Accurate detection of prostate boundaries is required in many diagnostic and treatment procedures for prostate disease. In this paper, a new paradigm for guided edge delineation is described, which involves presenting automatically detected prostate edges as a visual guide to the observer, followed by manual editing. This approach enables robust delineation of the prostate boundaries, making it suitable for routine clinical use. The edge-detection algorithm is comprised of three stages. An algorithm called sticks is used to enhance contrast and at the same time reduce speckle in the transrectal ultrasound prostate image. The resulting image is further smoothed using an anisotropic diffusion filter. In the third stage, some basic prior knowledge of the prostate, such as shape and echo pattern, is used to detect the most probable edges describing the prostate. Finally, patient-specific anatomic information is integrated during manual linking of the detected edges. The algorithm was tested on 125 images from 16 patients. The performance of the algorithm was statistically evaluated by employing five expert observers. Based on this study, we found that consistency in prostate delineation increases when automatically detected edges are used as visual guide during outlining, while the accuracy of the detected edges was found to be at least as good as those of the human observers. The use of edge guidance for boundary delineation can also be extended to other applications in medical imaging where poor contrast in the images and the complexity in the anatomy limit the clinical usability of fully automatic edge-detection techniques.     

Semiautomatic 3-D prostate segmentation from TRUS images using spherical harmonics

Prostate brachytherapy quality assessment procedure should be performed while the patient is still on the operating table since this would enable physicians to implant additional seeds immediately into the prostate if necessary thus reducing the costs and increasing patient outcome. Seed placement procedure is readily performed under fluoroscopy and ultrasound guidance. Therefore, it has been proposed that seed locations be reconstructed from fluoroscopic images and prostate boundaries be identified in ultrasound images to perform dosimetry in the operating room. However, there is a key hurdle that needs to be overcome to perform the ultrasound and fluoroscopy-based dosimetry: it is highly time-consuming for physicians to outline prostate boundaries in ultrasound images manually, and there is no method that enables physicians to identify three-dimensional (3-D) prostate boundaries in postimplant ultrasound images in a fast and robust fashion. In this paper, we propose a new method where the segmentation is defined in an optimization framework as fitting the best surface to the underlying images under shape constraints. To derive these constraints, we modeled the shape of the prostate using spherical harmonics of degree eight and performed statistical analysis on the shape parameters. After user initialization, our algorithm identifies the prostate boundaries on the average in 2 min. For algorithm validation, we collected 30 postimplant prostate volume sets, each consisting of axial transrectal ultrasound images acquired at 1-mm increments. For each volume set, three experts outlined the prostate boundaries first manually and then using our algorithm. By treating the average of manual boundaries as the ground truth, we computed the segmentation error. The overall mean absolute distance error was 1.26 +/- 0.41 mm while the percent volume overlap was 83.5 +/- 4.2. We found the segmentation error to be slightly less than the clinically-observed interobserver variability.     

Prostate mechanical imaging: 3-D image composition and feature calculations

We have developed a method and a device entitled prostate mechanical imager (PMI) for the real-time imaging of prostate using a transrectal probe equipped with a pressure sensor array and position tracking sensor. PMI operation is based on measurement of the stress pattern on the rectal wall when the probe is pressed against the prostate. Temporal and spatial changes in the stress pattern provide information on the elastic structure of the gland and allow two-dimensional (2-D) and three-dimensional (3-D) reconstruction of prostate anatomy and assessment of prostate mechanical properties. The data acquired allow the calculation of prostate features such as size, shape, nodularity, consistency/hardness, and mobility. The PMI prototype has been validated in laboratory experiments on prostate phantoms and in a clinical study. The results obtained on model systems and in vivo images from patients prove that PMI has potential to become a diagnostic tool that could largely supplant DRE through its higher sensitivity, quantitative record storage, ease-of-use and inherent low cost.     

Design and experimental evaluation of an intracavitary ultrasoundphased array system for hyperthermia

For evaluating the feasibility of treating prostate cancer, a 64-element linear ultrasound phased array applicator for intracavitary hyperthermia was designed and constructed. A 64-channel ultrasound driving system including amplifiers, phase shifters, and RF power meters was also developed to drive the array. The design of the array and driving equipment are presented, as are the results of acoustical field measurements and in vitro perfused phantom studies performed with the array. Several techniques for heating realistically sized tumor volumes were also investigated, including single focus scanning and two techniques for producing multiple stationary foci. The results show that the operation of the array correlated closely with the theoretical model. When producing a single stationary focus, the array was able to increase tissue temperature by 12°C in vitro in perfused phantom. With some minor improvements in array design, intracavitary phased arrays could be evaluated in a clinical environment     

基于相位编组的三维直肠超声导引图像中针检测算法研究

本文针对三维直肠超声导引前列腺介入式治疗中,针状手术器械定位难的问题,提出了一种三维超声图像中基于三维相位编组的针检测算法.该算法首先将体素按照梯度相位角进行分组,在得到的分组中用最小二乘拟合方法进行针状物体轴线提取,然后利用轴线体素的灰度统计特性进行端点定位.提出的方法在三维模拟数据、Agar 和鸡肉假体数据,以及三...