小波分析技术在椎旁及腰大肌肿块超声诊断中的应用

目的使用photoshop计算机技术,观察研究肿块组织的纹理空间分布特征表现,以提高超声诊断能力。方法将超声获取的图像组织,再经photoshop技术的变换和变换后的小波系数与图像的局部特征的对应关系进行分析,即:行细节按列排序,列细节按行排序,对角线细节按Z排序。结果通过对椎旁及腰大肌肿块组织的图像测定和小波技术分析,提供了频谱数据及图像的纹理分析信息,获取了病灶区域与正常组织的纹理定量的数据描述。结论小波分析技术为临床诊断椎旁及腰大肌肿块提供了分辨和分析病灶性质、程度的可靠依据。     

声触诊组织定量技术在颈部淋巴结疾病中的初步研究

目的研究分析声触诊组织定量技术在颈部淋巴结疾病诊断中的应用。方法 2013年4月~2013年12月,对我院78例颈部淋巴结肿大的患者行声触诊组织定量技术检查,获取病灶的VTQ值声触诊组织定量。根据病理结果将淋巴结分为良性、恶性两组,绘制受试者工作特征曲线(ROC曲线)并确定VTQ的诊断临界值。结果经检验,受检颈部淋巴结中,良、恶性的VTQ平均值分别为(2.28±0.83)m/s和(6.61±1.63)m/s,差异具有统计学意义。结论声触诊组织定量技术应用于诊断颈部淋巴结良、恶性具有可行性。     

甲状腺髓样癌超声结合声触诊组织弹性成像与病理基础对照

目的深入探讨甲状腺髓样癌(MTC)的超声及声触诊组织弹性成像(VTI)特征与病理基础的关系,进一步提高对MTC的认识和超声诊断水平。方法回顾性分析我院22例患者共28个病灶经病理证实为MTC的术前高频超声及VTI弹性成像图像指标,并与指标相应的组织病理学进行对比分析。结果病灶位于甲状腺中、上极22个,形态不规则20个,边界清晰19个,有声晕13个,低或极低回声26个,内部回声不均匀22个,出现钙化14个,混合血管型病灶18个,VTI弹性成像评分≥4分的19个,10例患者颈部出现转移性肿大淋巴结,对比病理结果,超声诊断恶性肿瘤准确率71.4%。结论 MTC与其病理组织学变化密切相关,高频超声及VTI弹性成像为诊断MTC提供了良好的影像学诊断方法。     

基于小波变换的超声图像纹理特征提取及前列腺癌诊断

目的 根据小波变换原理,研究了前列腺直肠超声图像中纹理特征的提取方法,并应用于前列腺癌的早期诊断.方法 本文提取出前列腺直肠超声图像中目标区域的小波变换纹理特征和边界频率特征,通过主分量分析方法(principal components analysis,PCA)对提取出的纹理特征进行选择,得到一个最优的特征子集.然后分别应用K均值聚类、支持向量机(suppoa vector machine,SVM)算法和AdaBoost(a-daptive boosting)算法来对所提取出的病变区域纹理特征进行分类.结果 对比实验结果表明,本文所提取的特征比单纯的使用灰度级差矢量(gray level difference vector,GLDV)具有更好的区分良恶性图像的能力,AdaBoost算法和SVM算法都能够有效地识别病变区域,识别正确率达到94.12%和93.46%.结论 使用本文算法可以为医生诊断提供有用的辅助信息,并提高诊断效率.     

颈部肿大淋巴结的超声诊断

超声技术在颈部肿大淋巴结的诊断中应用广泛,其不同的技术均存在优点与不足。常规二维超声能直观提供淋巴结形态及结构信息,但不具有特异性。多普勒超声能显示淋巴结血供状态,但受角度及血管内径影响。弹性成像技术能提示淋巴结硬度信息,但受操作医师手部施压力及主观感觉影响大。超声造影无创直观,但费用较高。超声引导下经皮穿刺活检能提供病理诊断,但微创手术仍存在风险。本文拟对不同超声技术在诊断颈部肿大淋巴结中的进展作一综述,以利于未来选择最为合适的超声技术。     

甲状腺隐匿性癌患者30例临床CT表现与病理比较

目的探讨甲状腺隐匿性癌(OCT)临床CT、超声的表现,以提升OCT影像学诊断水平。方法回顾我院收治的经手术病理证实的30例OCT患者CT和超声表现。对患者OCT的影像学资料(部位、形态、CT密度或回声、钙化情况等)进行分析,并与OCT的病理结果对照。结果 30例患者病灶共34个(单发27例,双发2例,三发1例)。圆形或类圆形病灶14个,不规则形病灶20个;边缘光整病灶11个,不光整病灶23个;甲状腺边缘连线完整病灶22个,连线中断病灶12个。病灶CT密度或回声均匀,无明显坏死囊变或出血。CT平扫显示低密度病灶21个,等密度病灶13个;超声显示实质性低回声病灶25个,混合性回声9个。CT检查见15个病灶存在钙化,而超声检查仅见9个病灶存在钙化。CT检查见9例患者颈部淋巴结肿大,超声见5例患者颈部淋巴结肿大。结论 OCT的影像表现与其病理特征相关,病灶边缘的不光整、边缘连线的中断、病灶的钙化、颈部淋巴结的肿大等影像学表现有助于OCT的诊断。     

多灶性甲状腺乳头状癌的超声及病理特征分析

目的探讨超声在诊断分析多灶性甲状腺乳头状癌(MPTC)特征中的价值。方法回顾性分析经病理证实的86例MPTC患者的术前超声检查声像图特征,按照微小癌及非微小癌、是否存在颈部淋巴结转移进行分组,比较两组病例的超声及临床病理特征。结果 86例MPTC患者共发现病灶210枚,术前超声检出甲状腺癌175枚,漏诊6枚,病理为直径0.2cm的微灶,误诊为结节性甲状腺肿29枚,超声诊断符合率83.3%(175/210)。病灶位于单侧26例,双侧60例。非微小癌50例,微小癌36例。16例(18.6%, 16/86)合并桥本甲状腺炎,31例(36%, 31/86)合并结节性甲状腺肿。颈部淋巴结肿大36例,31例出现转移灶。非微小癌组与微小癌组两者在血流分布及淋巴结转移方面差异有统计学意义(均P0.05)。与颈部无淋巴结转移组比较,淋巴结有转移组病灶个数有统计学差异(P0.05)。结论高频超声有助于多灶性甲状腺乳头状癌的诊断,对于微小癌,当合并多发良性结节及桥本甲状腺炎病变时,应注意综合分析,避免漏误诊。同时,应仔细观察颈部淋巴结情况,为临床诊断、治疗提供重要信息。     

超声引导下穿刺活检术对颈部淋巴结诊断的现状及进展

颈部淋巴结占全身淋巴结约1/3,全身各个部位的恶性肿瘤均有可能转移到颈部淋巴结致其肿大,因此明确其性质对恶性肿瘤分期、治疗计划制定和疗效分析等具有重要意义.目前,超声引导下穿刺活检被认为是非手术条件下获取明确病理组织学诊断的最佳方法之一.该文探讨了超声引导下穿刺活检术在颈部淋巴结病变病理学诊断中的临床应用价值及研究进展...     

双源CT双能量虚拟平扫技术在颈部淋巴结病变中的应用价值

目的 探讨双源CT双能量虚拟平扫技术在颈部肿大淋巴结中的临床应用价值.方法 回顾分析48例经病理证实并行颈部CT常规平扫及双能量模式增强扫描的颈部淋巴结肿大患者的影像资料,利用"Liver VNC"软件处理得到虚拟平扫图像.对颈部肿大淋巴结虚拟平扫(virtual noncontrast,VNC)图像和常规平扫(conventional noncontrast,CNC)图像在平均CT值、噪声,信号噪声比(signal to noise ratio,SNR),图像质量,对病灶的显示情况,辐射剂量(用CTDIvol和DLP表示)等方面进行比较研究.结果 常规平扫和虚拟平扫所测颈部肿大淋巴结的平均CT值差异无统计学意义(P>0.05);虚拟平扫图像噪声明显低于常规平扫,而信号噪声比明显高于常规平扫(P<0.05);虚拟平扫图像质量低于常规平扫但差异无统计学意义(P>0.05);虚拟平扫及常规平扫对颈部肿大淋巴结内坏死均可见显示;双能量扫描模式较常规扫描模式的总辐射剂量小(P<0.05).结论 在颈部肿大淋巴结检查中,1次双能量增强扫描可获得增强图像和VNC图像,而VNC图像基本不影响病灶的观察同时显著降低了辐射剂量,具有潜在的临床应用价值.     

艾滋病患者颈部包块的超声表现

目的: 探讨艾滋病患者颈部包块的超声声像图特征.材料和方法: 对21例艾滋病患者颈部包块行超声检查并结合临床资料分析其图像特征.结果: (1)超声表现: 21例病例中有20例的超声表现为淋巴结肿大.其中,16例≥3cm的淋巴结/融合团块内可见大片无回声区,其内见细小点状回声漂浮,探头加压后见细小点状回声移动,彩色多普勒超声表现为尚存的实性回声部分可探及较多的红蓝彩色血流信号.(2)临床诊断: 16例为淋巴结结核,2例为真菌感染,2例为化脓性细菌感染,1例病理符合坏死组织之改变,培养未见真菌、细菌,病因学未明.结论: 艾滋病患者颈部包块淋巴结炎可能性大,其声像图表现具有一定特征.     

Photoshop软件在自体角膜转位手术中的运用

目的 提高自体角膜转位手术的可预测性、直观性.方法 用Photoshop图像处理软件,对准备进行自体角膜转位的角膜照片进行预切取,并在电脑上进行模拟手术旋转,以直观分析手术可能产生的效果.结果 用Photoshop图像处理软件产生的手术后模拟效果与实际手术疗效基本吻合.结论 Photoshop图像处理软件可大大提高自体角膜转位术的可预测性,有利于手术选择最佳手术部位,并帮助判断手术疗效.     

Ultrasound motion estimation using a hierarchical feature weighting algorithm.

The quality of ultrasonic images is usually influenced by speckle noises and the temporal decorrelation of the speckle patterns. Most traditional motion estimation algorithms are not suitable for speckle tracking in medical ultrasonic images which usually have a low signal-to-noise ratio (SNR). This paper proposes a new motion estimation algorithm that is designed for assessing the dense velocity fields of soft tissue motion in a sequence of ultrasonic B-mode images. We design a hierarchical maximum a posteriori estimator together with an adaptive feature weighted mechanism to estimate the motion field from an ultrasonic image sequence. The proposed method was compared with several existing motion estimation methods via a series of experiments with synthetic speckle image sequences. Performance was also tested on in vivo ultrasonic images. The experimental results show that motion can be assessed with better accuracy than other methods for synthetic speckle images and a good correspondence with clinicians' observations has also been achieved for clinical ultrasonic images.     

Optimization of multiplanar reformations from isotropic data sets acquired with 16-detector row helical CT scanner

Institutional review board approval and waiver of consent were obtained for the patient component of this retrospective HIPAA-compliant study. By using an anthropomorphic phantom and metal oxide semiconductor field effect transistor detectors, radiation dose was determined for one eight-detector row and two 16-detector row computed tomographic (CT) protocols. A custom phantom was scanned by using the three protocols to identify isotropy. Contrast-to-noise ratios (CNRs) were determined for the same protocols by using a third phantom. Seven patients had undergone isotropic 16-detector row CT of the abdomen and pelvis. Anonymized coronal reformations at various thicknesses were ranked qualitatively by three radiologists. Effective dose equivalents were similar for the eight- and 16-detector row protocols. When transverse and coronal reformations of data acquired in the custom phantom were compared, coronal reformations obtained with the 16-detector row and 0.625-mm section thickness protocol were found to be nearly identical to the transverse image for all sets of line pairs. CNRs were consistently highest on 5-mm-thick coronal reformations (CNR range, 1.2-3.3). For qualitative assessment, 2- and 3-mm-thick coronal reformations were consistently preferred.     

Multiplanar and 3D imaging of the central airways: comparison of image quality and radiation dose of single-detector row CT and multi-detector row CT at differing tube currents in dogs

PURPOSE: To compare in an animal model the image quality of multiplanar reformation and three-dimensional (3D) reconstruction images of the central airways by using single-detector row computed tomography (CT) and multi-detector row CT at varied tube currents and to compare radiation dose. MATERIALS AND METHODS: Five dogs each underwent five consecutive helical CT examinations (one single-detector row CT examination at 240 mA and four multi-detector row CT examinations at 240, 120, 40, and 20 mA), with 0.8-second gantry rotation time. Multiplanar reformation and 3D reconstruction images were created from each of the 25 CT acquisitions. The images were randomized and blindly reviewed with consensus agreement by three radiologists who graded image quality by using a five-point scale. In a separate review, the three radiologists independently used a four-point scale to rank the comparative image quality of the multi-detector row CT 3D images, while blinded to specific tube currents. The radiation doses were measured for each type of scan, and the relative radiation dose length products that were normalized to single-detector row CT values were used to compare radiation doses of the various CT techniques. Statistical analysis was performed with the Wilcoxon signed-rank test and the Friedman analysis of variance test. RESULTS: Image quality was consistently ranked higher for multi-detector row CT images than for single-detector row CT images (P =.03). Although there were no distinguishable differences between images obtained with multi-detector row CT at 240, 120, or 40 mA, images obtained with 20 mA were given a significantly (P =.04) lower relative rank (mean, 2.4) than those obtained with higher tube currents (mean, 1.4-1.7). Multi-detector row CT radiation doses were 1.64, 0.82, 0.27, and 0.14 (for 240-, 120-, 40-, and 20-mA multi-detector row CT, respectively) relative to the dose for 240-mA single-detector row CT. CONCLUSION: Multi-detector row CT is superior to single-detector row CT for multiplanar and 3D imaging of the central airways. Substantial dose reductions can be made, while maintaining high image quality.     

Single- versus multi-detector row CT of the brain: quality assessment

PURPOSE: To assess the quality of brain computed tomographic (CT) studies obtained with a four-channel multi-detector row CT scanner compared with those obtained with a single-detector row CT scanner. MATERIALS AND METHODS: Forty-seven patients referred for brain CT were imaged with both single- and multi-detector row scanners. Single-detector row CT images were acquired by using a 5-mm-collimated beam in the transverse mode. Multi-detector row CT images were acquired in four simultaneous 2.5-mm-thick sections, which were combined in projection space to create two contiguous 5-mm-thick sections. Two neuroradiologists blinded to the acquisition technique independently evaluated the CT image pairs, which were presented in a stacked mode on two adjacent monitors. Each study was graded by using a five-point scale for posterior fossa artifact, overall image quality, and overall preference. RESULTS: Multi-detector row CT studies were acquired 1.8 times faster than single-detector row CT studies (0.92 vs 0.52 section per second). Multi-detector row CT posterior fossa artifact was less than single-detector row CT posterior fossa artifact in 87 (93%) of 94 studies. Overall preference was expressed for multi-detector row CT in 84 (89%) of 94 studies. The differences in mean posterior fossa artifact scores (P <.001) and mean overall image quality scores (P =.001) were significant. CONCLUSION: Brain CT images obtained with multi-detector row CT resulted in significantly less posterior fossa artifact and were preferred to single-detector row CT images.     

Clinical efficacy of a new software developed for dental digital subtraction radiography

OBJECTIVES: The aim of this study was to test and compare the efficacy of software developed recently for digital subtraction radiography (DSR) in vivo. METHODS: An algorithm performing both manual and automated image reconstructions and contrast correction was developed for the manipulation of radiographic images. Pre- and post-operative radiographic images of ten patients were obtained and the automated subtraction analyses were performed using four different softwares (new software, Emago, Photoshop 8.0 and Paintshop Pro 9). Ten experienced dental specialists evaluated the clinical efficacy of each program and scored the softwares by using visual analogue scales (VAS). The results were statistically analysed and alpha was set as 0.05. RESULTS: The newly developed algorithm received higher scores than the others (new software =67.89, Emago = 64.26, Paintshop Pro 9 = 33.41 and Photoshop 8.0 = 27.24, respectively). The clinical efficacies of the new software and Emago were not significantly different (P = 0.720); likewise, Photoshop 8.0 and Paintshop Pro 9 performed comparably (P = 0.295). CONCLUSIONS: Considering this study, the new software and Emago would be suggested for DSR in dental practice.     

MRI中T_1W WATS/FFE序列在肾脏疾病中的应用价值

目的:探讨MRI中T1加权选择水激励梯度回波成像(T1W/WATS/FFE)序列在肾脏疾病检查中的应用价值。方法:对临床拟诊和CT及超声检查后诊断为肾脏病变的211例患者,应用MRI中T1W/WATS/FFE序列进行扫描,分析该序列在肾脏疾病成像中的特点。结果:显示正常肾脏28例。肾脏病变183例,其中良性病变166例,恶性肿瘤17例。肾脏显示分为良好、一般、差三种,肾脏显示良好207例,一般2例,差2例。结论:MRI中T1W/WATS/FFE序列能很好地显示肾脏的结构,与周围组织和器官及病变对比度增加,扫描速度快成像时间短,图像质量高,能够满足临床的诊断要求。     

RARE-MR urography: a fast nontomographic imaging procedure for demonstrating the efferent urinary pathways using nuclear magnetic resonance

RARE-MR-Urography is a new fast data acquisition technique for magnetic resonance imaging. As a non-tomographic approach to the morphology of the urinary system, image information is similar to intravenous X-ray urography. As the sequence results in a heavily T2-weighted image displaying aqueous fluids, application of contrast agents is not necessary. Image quality is demonstrated by an exemplary case. Basic technical details and possible indications are discussed.     

A five-step approach to digital image manipulation for the radiologist.

Digital manipulation of images plays a key role in development of multimedia presentations. Five basic steps to digitizing images and preparing them for publication and computer presentation are scanning, correction, editing and labeling, saving files, and producing final output. These steps can be completed with commercially available hardware and image manipulation software (eg, Photoshop). The higher the quality of the original scanned image, the more image data there will be to edit: A good image cannot be created from an inferior scan. The most important functions for properly scanning images are size, resolution, and color. Resolutions of 300 ppi and 72 ppi should be used for print publication and computer presentations, respectively. The higher resolution image has the larger file size. The scanned image should be saved as a TIFF (tagged image file format), which is an uncompressed file type used for printed images. The Joint Photographic Experts Group (JPEG) format compresses the size of the image file but also reduces image quality. The JPEG format is a good choice if a small file size is needed, such as in Web and PowerPoint presentations. If the user needs to save an image as a JPEG file, the image should be edited first and then saved once in JPEG format. With Photoshop, the user can rotate and crop an image; adjust its brightness, contrast, and color; remove unwanted patient information, dust, and scratches; and add text and symbol labels to enhance images for teaching purposes. Digital manipulation can be fast and effective if the user has some basic knowledge and tools.