哑型急性肺栓塞的临床研究

目的 探讨哑型急性肺栓塞（APE）患者的临床特点和预后。方法 51 例经肺动脉增强CT确诊,但无明显肺栓塞常见临床特征的哑型APE患者予以低分子肝素钠、华法林抗凝治疗。分析患者D- 二聚体、血管彩超、心脏彩超、心电图检查结果,并观察治疗后情况,了解哑型APE患者的临床特点及预后。结果 51 例患者均痊愈出院,4 例患者因出现活动性出血停止抗凝治疗。31 例患者在3个月后复查肺动脉增强CT 未见明显栓塞征象,其余16 例患者在4~6 月后肺栓塞征象消失。结论 哑型APE患者临床表现不典型,肺动脉增强CT 检查是明确诊断的金标准,D-二聚体、心电图等可作为相应的补充,经过恰当及时的治疗,患者预后良好。     

麻醉前视频宣教对全麻患者麻醉信息获取、术前焦虑及麻醉满意度的影响

目的 观察在麻醉前访视时辅助视频宣教对全麻患者麻醉信息获取、术前焦虑及麻醉满意度的影响。方法 将105 例全麻患者采用随机数字表法分为视频组（V 组）53 例和常规组（N 组）52 例,麻醉前访视后,所有患者完成访视内容问卷、STAI状态焦虑评分量表（S-AI）及焦虑视觉类比试验（AVAT）评分,术后24h 填写麻醉满意度评分,记录入手术室后10min的心率和平均动脉压值。结果 V 组问卷分数（3.80±1.21）分,显著高于N 组患者（2.79±1.03）分（P＜0.01）,V 组患者S-AI 评分（43.11±8.72）分,高于N 组患者（38.37±10.72）分（P＜0.05）,V 组患者AVAT 评分为（3.15±0.82）分,N 组患者（2.94±0.75）分（P ＞0.05）,V 组患者满意度评分（95.90±5.49）分,高于N 组患者（92.20±5.95）分（P＜0.05）。结论 对全麻患者麻醉前访视时进行视频宣教和告知,能增加其对宣教和告知内容信息的获取量,提高患者的麻醉满意度;但难以判断其对于术前焦虑的影响。     

CDE、CDUS检查评估活动期强直性脊柱炎患者骶髂关节炎的价值

目的探讨彩色多普勒能量图（CDE）、彩色多普勒超声（CDUS）检查评估活动期强直性脊柱炎（AS）患者骶髂关节炎的应用价值。方法对36例活动期AS患者的72个骶髂关节进行MRI检查,筛选出存在活动性炎症的63个骶髂关节（病例组）及25例健康志愿者的50个骶髂关节（对照组）作超声检测,对比血流显示率、血流丰富程度（半定量分级）及血流阻力指数（RI）,并对治疗后病情缓解的31例AS患者的54个骶髂关节行CDE、CDUS检查,对比活动组及病情缓解组的血流显示率、血流丰富程度及血流RI。结果病例组骶髂关节内部或周边血流显示率（90.5％）较对照组（52.0％）高,两组间差异有统计学意义（P=0.000）;病例组以2～3级多血流为主,而对照组以0～1级少血流为主,病例组与对照组间骶髂关节血流丰富程度的差异有统计学意义（P=0.000）;病例组平均动脉血流RI为0.57±0.07,较对照组的0.78±0.11低,两组间差异有统计学意义（P=0.000）。活动组的平均动脉RI 0.57±0.08较病情缓解组0.69±0.09低,两组间差异有统计学意义（P=0.000）;而活动组与病情缓解组的骶髂关节内部或周边血流显示率及血流丰富程度差异均无统计学意义（P=0.086、0.052）。结论彩色超声可显示骶髂关节异常血流信号,尤其是低阻血流信号为诊断AS患者骶髂关节炎并评估其活动性提供了重要的参考依据。     

急性脑梗死患者脑微出血的发病情况及其危险因素分析

目的探讨急性脑梗死患者脑微出血的发病情况及其危险因素。方法选择急性脑梗死患者75例,男51例,女24例,年龄42～83（64.9±10.8）岁。行头颅CT、磁敏感成像（SWI）检查,依据脑微出血检出的结果分成阳性组（23例）与阴性组（52例）,比较两组的一般资料,探讨脑微出血发病的危险因素。结果SWI检查的检出率比CT检出率高（χ2=27.17,P＜0.05）。阳性组年龄、高血压病、糖尿病患病率均较阴性组高,差异均有统计学意义（均P＜0.05）;两组性别、血脂异常、心房颤动、冠心病、吸烟、饮酒情况比较,差异均无统计学意义（均P＞0.05）。logistic回归分析显示年龄增长、高血压病是脑微出血的独立危险因素（P＜0.05）。结论急性脑梗死患者合并存在脑微出血的比例高,SWI检查是检测脑微出血的敏感方法,年龄大、高血压病与脑微出血的发生密切相关。     

后腹腔镜下肾部分切除术后发生尿瘘的危险因素分析

目的 分析和探讨后腹腔镜下肾部分切除术后发生尿瘘的危险因素。方法统计和分析2004-10-2013-06 行腹 腔镜下经后腹膜路径肾部分切除术后发生尿瘘的128 例肾肿瘤患者的临床资料,尿瘘严格定义为手术2d 后仍从后腹膜引流管持续引流出尿液。结果术后有14 例（10.9%）患者发生尿瘘。发生尿瘘的患者中10 例（71.4%）未行CTA 检查,术中平均出血量（232.3±86.7）ml,平均肾动脉阻断时间（28.2±7.5）min,平均住院时间（13.1±2.1）d,9 例（64.3%）术中发现集合系统破损。单因素分析提示年龄（P =0.1102）、糖尿病（P =0.0445）、肿瘤内生型生长（P =0.0835）、术前是否行CTA 检查（P=0.0137）、集合系统损伤（P=0.0935）、肾动脉阻断时间（P =0.1225）及术中出血量（P=0.0045）是发生尿瘘的危险因素;多因素分析提示糖尿病（P =0.0381）、术前是否行CTA 检查（P =0.0433）及术中出血量（P =0.0155）是术后发生尿瘘的独立危险因素。结论糖尿病、术中出血 量及术前是否行肾脏CTA 检查是后腹腔镜下肾部分切除术后发生尿瘘的独立危险因素。减少术中出血有利于术者获得清晰的操作视野,有效缝合破损的集合系统,从而防止尿瘘的发生。     

宝石能谱CT对胃癌区域淋巴结转移的诊断价值

目的 研究宝石能谱CT（gemstone spectral CT,GSCT）对胃癌区域淋巴结转移的诊断价值。方法 回顾分析52例胃镜下组织学活检证实为胃癌并行GSCT（GSCT 组,24 例）或双源CT（dual source CT,DSCT）（DSCT 组,28 例）的患者,两组除常规CT增强检查外,GSCT在动脉期应用能谱成像GSI（gemstone spectral imaging）软件,获得区域转移淋巴结与胃癌病变的能谱衰减曲线,对比分析两组CT结果与术后病理结果符合率及GSCT 对转移淋巴结评估的准确性。结果 通过计算淋巴结大小、CT 值差值及短长径比值的方法,GSCT 组评估淋巴结转移与病理符合率高于DSCT 组（P＜0.05）;胃癌及转移淋巴结能谱分析结果无统计学差异（P≥0.05）。结论 GSCT 检查胃癌区域淋巴结转移与病理结果的一致性高于DSCT;GSCT可对胃癌术前转移淋巴结进行详细判断,并对术前评估提供了理论依据和技术支持,具有重要的临床应用价值。     

完全腹腔镜胰十二指肠切除术6例临床疗效分析

目的 评估完全腹腔镜胰十二指肠切除术（laparoscopic pancreaticoduodenectomy,LPD）的可行性、安全性。方 法 采用LPD 治疗胰头或十二指肠肿瘤患者6 例,回顾性分析手术时间、术中出血量、淋巴结清扫数目、术后肛门排气时间、术后住院天数、手术并发症发生率及术后短期疗效。结果 6 例手术均在完全腹腔镜下完成,无中转开腹病例。手术时间（380.5±38.1）min;出血量（241.7±189.3）ml;清扫淋巴结（15.3±2.8）枚;平均肛门排气时间（3.5±1.0）d;术后住院（14.0±5.7）d。手术并发症发生率为33.3％（2/6）,其中轻度胰漏1例,肺炎1例;本组患者术后随访3~12个月,无肿瘤复发及转移。结论 LPD 安全、可行,能达到胰头或十二指肠肿瘤根治性切除的目的。     

术前超声双重造影检查对胃癌患者胃周淋巴结转移的评估价值

目的探讨超声双重造影检查（DCUS）在不同部位胃癌术前淋巴结转移评估中的应用价值。方法选择180例胃癌患者,手术前3～5d内均进行DCUS及螺旋CT检查,对不同部位的胃癌患者术前均进行淋巴结分站评估,与术后病理检查结果对照得出正确率,并进行相互间比较。结果 DCUS和螺旋CT检查对远端胃切除患者淋巴结转移判断正确率分别为86.0%和83.9%,对全胃切除患者的判断正确率分别为82.5%和85.0%,两种检查方法判断准确率差异均无统计学意义（P＞0.05）;DCUS对近端胃切除患者淋巴结转移判断正确率为66.0%,明显低于螺旋CT检查的85.1%,差异有统计学意义（均P＜0.05）。结论胃癌术前淋巴结转移评价中,超声双重造影检查判断正确率与螺旋CT相当,仅对贲门胃底部癌判断正确率略低。     

IDUS、CT和MRCP对胆道恶性梗阻的诊断价值

目的探讨腔内超声（IDUS）、CT和磁共振胰胆管造影（MRCP）和对胆道恶性梗阻的诊断价值。方法回顾性分析53例胆道恶性梗阻患者的IDUS、CT和MRCP检查结果,比较3种影像学检查方法对胆道恶性梗阻的图像特征和诊断情况。结果IDUS、CT和MRCP对胆道恶性梗阻定位诊断准确率分别为65.31%、82.98%和82.93%,差异有统计学意义（P＜0.05）;而定性诊断准确率分别为63.27%、74.47%和75.61%,差异无统计学意义（P＞0.05）。3种影像学检查方法均能显示胆道恶性梗阻的部位、数量和回声/密度/信号特征：CT和MRCP对壶腹癌定位诊断、胰头癌定性诊断均有较高符合率。IDUS对胆管狭窄性质的阴性预测能力明显高于CT和MRCP（P＜0.05）。结论IDUS、CT和MRCP均能清晰显示胆道恶性梗阻的特征,各有优势,具有较高的应用价值。     

三维斑点追踪成像评价甲状腺功能亢进患者左心室收缩功能改变的应用价值

目的 探讨三维斑点追踪成像（3D-STI）技术在评价甲状腺功能亢进(甲亢)患者左心室整体收缩功能中的应用价 值。方法 选择50 例甲状腺功能亢进患者与45 例健康志愿者,获取心尖四腔心切面动态图像,存储左心室三维全容积动态图像后,运用3D-STI 软件进行脱机分析,得到两组收缩期左心室整体纵向峰值应变（GLS）、圆周峰值应变（GCS）、左心室扭转度角度峰值(LV-tw)、左心室扭力（LV-tor）、左心室心底水平旋转角度峰值（Prot-B）、左心室心尖水平旋转角度峰值（Prot-A）及左心室射血分数（LVEF）等,比较两组三维应变（3DS）指标之间的差异。结果 与正常对照组比较,甲亢组的左心室收缩功能增强,GLS、GCS 分别为（-20.47±3.08）% vs.（-18.52±4.77）%、（-28.98±3.00）% vs.（-25.88±2.12）%,两组差异均有统计学意义（均P＜0.05）;甲亢组LV-tw、LV-tor、LVProt-A、LVProt-B 均较正常对照组略有增加,但差异均无统计学意义（均P＞0.05）。结论 3D-STI 可无 创、敏感检测甲亢患者左心室三维应变,为临床客观评估甲亢左心室收缩功能提供一种新方法。     

Asymptotics of pseudodifferential operators acting on functions with corner singularities

A new definition of the expansion in smoothness of a distribution at a point is introduced. Some properties of the new expansion are studied and a uniqueness result for the coefficients of the expansion is proved. The main application of the definition is for obtaining the asymptotics in smooth ness of pseudodifferential operators acting on a function near a corner point of singsupp f. An example of usage of the obtained results in computed tomog raphy is presented.     

Nonlocal spatial clustering in automated brain hematoma and edema segmentation

Hematoma and edema volume are potential predictors of 30‐day mortality rate and functional outcome (degree of disability or dependence in daily activities after a stroke) for patients with intracerebral hemorrhage. The manual segmentation of hematoma and edema from computed tomography scans is common practice but a time‐consuming and labor‐intensive task. Automated segmentation is an appealing alternative, but it is challenging because of the poorly defined boundary between edema and the surrounding healthy brain tissue. There is limited literature on this problem, and we aim to help fill the gap between the theoretical development of segmentation methods and the practical need. Our framework is fully automated and requires no supervision. The method uses nonlocal regularized spatial fuzzy C‐means clustering in the initialization stage and the active contour without edges method in the refinement stage. To evaluate it, we used 30 subjects with different sizes, shapes, and locations of hematoma and edema. Compared with the manual segmentation results from two independent raters, our method performs hematoma segmentation well, with an average dice score coefficient of 0.92. Although there is a lack of ground truth in edema segmentation due to the high inter and intrarater variation, our results are comparable with manual segmentation results.     

ACCURATE ATTENUATION CORRECTION FOR ALGEBRAIC RECONSTRUCTION TECHNIQUE IN SPECT

We present a new iterative reconstruction algorithm to improve the algebraic reconstruction technique （ART） for the Single-Photon Emission Computed Tomography. Our method is a generalization of the Kaczmarz iterative algorithm for solving linear systems of equations and introduces exact and implicit attenuation correction derived from the attenuated Radon transform operator at each step of the algorithm. The performances of the presented algorithm have been tested upon various numerical experiments in presence of both strongly non-uniform attenuation and incomplete measurements data. We also tested the ability of our algorithm to handle moderate noisy data. Simulation studies demonstrate that the proposed method has a significant improvement in the quality of reconstructed images over ART. Moreover, convergence speed was improved and stability was established, facing noisy data, once we incorporate filtration procedure in our algorithm.     

Boundary functions in L2 H $$(\mathbb{B}^n )$$

We solve the Dirichlet problem for line integrals of holomorphic functions in the unit ball For a function u which is lower semi-continuous on we give necessary and sufficient conditions in order that there exists a holomorphic function f ∈ such that

实时三维超声心动图与640层CT定量评价冠心病患者左心室容积及收缩功能的对比研究

目的应用实时三维超声心动图（RT-3DE）和640层CT（640- MSCT）定量评价左心室容积和收缩功能,探讨两种方法测值的相关性及在左心功能评价中的应用价值。方法选择临床或冠状动脉造影确诊为冠心病的患者42例,分别行RT-3DE和640- MSCT心脏增强（分别采用自动法和手动法）检查,测量指标包括：左心室舒张末期容积（LVEDV）、左心室收缩末期容积（LVESV）、左心室每搏输出量（LVSV）和左心室射血分数（LVEF）。将两种方法各测量值的结果进行比较。结果（1）RT-3DE测得左心容积及功能指标与640- MSCT （自动、手动两种方法）测值（LVEDV、LVESV、LVSV及LVEF）间相关性较好（P＜0.01）;（2）640- MSCT与RT-3DE左心室容积与心功能测值之间差别在于：LVEDV、LVESV两项指标640- MSCT测值均高于RT-3DE测值（P＜0.05）,LVSV值640- MSCT测值稍高于RT-3DE测值（P＞0.05）,而LVEF值640- MSCT测值稍低于RT-3DE测值（P＞0.05）。结论640- MSCT与RT-3DE在评价冠心病患者左心容积及功能方面高度相关,RT-3DE可推荐为临床首选影像学检查;根据不同患者的病情和各自特点,将640- MSCT与RT-3DE结合使用,可提高临床的影像学诊断率,为临床提供更多的诊疗信息。     

Bounds on the quality of reconstructed images in binary tomography

Binary tomography deals with the problem of reconstructing a binary image from its projections. In particular, there is a focus on highly underdetermined reconstruction problems for which many solutions may exist. In such cases, it is important to have a quality measure for the reconstruction with respect to the unknown original image.     

Approximate inverse meets local tomography

Local or lambda tomography reconstructs Λƒ which has the same discontinuities as the searched‐for density distribution ƒ. Computing Λƒ, however, requires only local tomographic measurements. Local tomography is usually implemented by a filtered backprojection algorithm (FBA). In the present article we design reconstruction filters for the FBA such that Λ^2m+1ƒ will be reconstructed for a given m∈ℕ₀. Moreover, we prove convergence and convergence rates for the FBA as the discretization step size goes to zero. To this end we express the FBA in the framework of approximate inverse. Based on our analysis we further propose a scheme which yields a proper scaling of the reconstruction filters. Numerical experiments illustrate the analytic results. Copyright © 2000 John Wiley & Sons, Ltd.     

New regularized algorithms based on the spectral method for solving deformable layer tomography

The deformable layer tomography (DLT) is now a popular way to characterize the unknown geometry of the velocity interface by using the traveling time observed in data, which is difficult to solve accurately, because of the strong ill-posedness. In this paper, new regularization approaches based on the spectral method are introduced, which can invert the velocity value and the geometry of the interface simultaneously. The unknown interfaces are parameterized by Legendre spectral expansion, and various regularization methods combined with traditional regularization parameters selections are utilized to solve the ill-conditioned algebraic equation system. Moreover, a regularized algorithm with prior choice of regularization parameters is proposed to solve the DLT.     

Generic iterative subset algorithms for discrete tomography

Discrete tomography deals with the reconstruction of images from their projections where the images are assumed to contain only a small number of grey values. In particular, there is a strong focus on the reconstruction of binary images (binary tomography). A variety of binary tomography problems have been considered in the literature, each using different projection models or additional constraints. In this paper, we propose a generic iterative reconstruction algorithm that can be used for many different binary reconstruction problems. In every iteration, a subproblem is solved based on at most two of the available projections. Each of the subproblems can be solved efficiently using network flow methods. We report experimental results for various reconstruction problems. Our results demonstrate that the algorithm is capable of reconstructing complex objects from a small number of projections.