Quantitative assessment of transient left ventricular asynergy in coronary artery disease

The purpose of this study was to determine the diagnostic value of quantitative two-dimensional echocardiography during transesophageal atrial pacing in assessing the presence and severity of coronary artery disease. Apical four- and two-chamber views were registered at rest and at different pacing rates. Computerized quantitative evaluation of left ventricle wall motion was performed. On the basis of left ventricle wall motion analysis data of 22 individuals with no coronary pathology, as assessed by angiography and with negative exercise ECG and transesophageal atrial pacing ECG test, nomograms for assessment of wall motion abnormalities and for calculation of asynergy area as a measure of wall motion abnormality extent were obtained. The method revealed new transient wall motion abnormalities during pacing or exacerbation of old ones present at rest in 83 of the 89 patients with angiographically proven coronary artery stenosis greater than or equal to 70% and in 3 of the 32 controls with no changes in their coronary angiograms. Thus, it showed high sensitivity (93%), specificity (91%), predictive value of positive result (96%), predictive value of negative result (83%), and efficiency of the test (93%). These values appeared to be higher than those calculated for transesophageal atrial pacing ECG, recorded simultaneously with echocardiographic images (81, 87, 95, 62, and 83%, respectively) and for exercise ECG test which was performed in 66 coronary patients and in 29 controls (68, 86, 92, 54, and 74%, respectively). The extent of pacing-induced left ventricular regional wall motion abnormalities appeared to be directly correlated to the extent of coronary artery disease.(ABSTRACT TRUNCATED AT 250 WORDS)     

DCE-MRI及IVIM模型在直肠癌病理分级中的应用及其灌注参数的相关性

目的探讨动态增强磁共振成像(DCE-MRI)定量参数、体素内不相干运动(IVIM)不同模型在直肠癌病理分级中的应用价值,比较两者灌注指标的相关性。资料与方法收集行动态增强及多b值扩散加权成像扫描,且经手术或肠镜病理证实为直肠癌的37例患者,其中高分化11例,中分化12例,低分化14例,测量DCE-MRI参数容积转移常数(K^trans)、速率常数(Kep)和血管外细胞外容积分数(Ve),IVIM模型中标准表观扩散系数(标准ADC)、双阶单指数纯扩散系数(D-mono)、灌注系数(D^*-mono)、灌注分数(f-mono)及双阶双指数模型纯扩散系数(D-Bi)、灌注系数(D^*-Bi)、灌注分数(f-Bi),检验数据一致性,比较不同病理分化程度直肠癌各参数值的差异及各组间参数值的差异,分析各灌注指标间的相关性。结果观察者间测量数据一致性良好(ICC>0.5)。DCE-MRI参数K^trans、Ve值及IVIM模型参数D-mono及D^*-mono值在不同病理分级的直肠癌中差异有统计学意义(P<0.05),低分化组Ktrans及Ve值均高于高分化组;低分化组D-mono值低于高分化组,D*-mono值高于高分化组,且随着分化程度降低,D-mono值逐渐降低,D^*-mono值逐渐升高,差异有统计学意义(P<0.05);Ve与f-Bi呈正相关(r=0.365,P=0.026)。结论DCE-MRI及IVIM模型可为直肠癌病理分级的术前评估提供较可靠的定量参数。IVIM模型的f-Bi值与DCE-MRI灌注参数Ve具有相关性。     

多层螺旋CT后处理技术对小儿气道异物的诊断价值

目的探讨多层螺旋CT后处理技术在小儿气道异物临床诊断中的应用价值。方法对我院39例疑似气道异物患儿行64排CT平扫后利用后处理技术重建图像资料,影像诊断为气道异物,并回访临床支气管镜下异物探查结果进行分析讨论。结果39例患儿中提供异物吸入史的为36例,37例支气管镜下异物探查取出术结果证实为阳性,准确率达95%,2例误诊,误诊率为5%;其中2例出现阻塞性肺炎,右侧支气管21例,左侧支气管15例,支气管分叉处1例。结论根据患儿有无吸入史,结合多层螺旋CT后处理技术后重建图像,对气道异物诊断、定位及临床治疗和预后提供了重要价值。     

股骨颈骨折术后股骨头坏死的影像学及发病因素分析

目的调查股骨颈骨折闭合复位加压内固定术后股骨头坏死的影像学表现,分析其发病因素。方法回顾性分析2006年2月至2013年3月期间接受闭合复位内固定治疗的782例股骨颈骨折患者。平均随访（6.3±2.4）年,筛选出术后出现股骨头坏死的患者132例,使用Ficat分期标准对患者进行影像学表现分期,将患者的年龄、性别、伤侧、骨折复位满意度等基本资料运用Logistic回归进行多因素分析。结果不同年龄组股骨头坏死的Ficat分期差异有统计学意义（CMH统计量为4.321,P=0.026）;男、女的Ficat分期分布情况差异无统计学意义（CMH统计量为1.532,P=0.224）。多因素回归分析显示骨折的移位程度、骨折复位质量与股骨头坏死明显相关（OR分别为2.327,4.213）。结论闭合复位加压螺纹钉内固定治疗股骨颈骨折效果较好,骨折移位程度及骨折复位质量对术后股骨头坏死的发生有明显的影响。     

人工全膝关节置换中截骨技术的研究进展

目的 探讨人工全膝关节置换术（TKA）中截骨方法的研究进展。方法 在PubMed、Springer Link、FMJS、万方网络数据库中,以“膝关节置换术”、“截骨”、“计算机导航”和“个体化模板”为关键词,查阅1988年1月—2014年6月有关人工TKA中截骨技术研究的相关文献,进行分析和总结。结果 TKA是治疗中晚期膝关节疾病的标准经典手术,术中截骨方法主要有传统器械截骨、计算机导航及个体化模板辅助截骨等。TKA中传统器械截骨,依靠机械引导装置定位及术者经验截骨,主观性强,精确度较低,手术风险大,并发症多,手术效果欠佳。与传统器械截骨相比,计算机导航辅助截骨精度可能受多种因素影响,需要的时间和并发症发生的概率更多;另外,由于其学习曲线长、设备费用昂贵、技术要求高等众多因素,限制了导航系统的推广应用。个体化模板辅助TKA技术可设计精确化的截骨方法或工具,实现个体化解剖截骨,具有提高截骨精确性、缩短手术时间、减轻手术损伤等优势,膝关节术后功能恢复更加理想。结论 随着数字骨科的不断发展,人工TKA手术方案会更加个性化,截骨更精确。数字化、个体化截骨技术可能成为今后TKA发展的新方向。     

Organization of ventrolateral periolivary cells of the cat superior olive as revealed by PEP-19 immunocytochemistry and Nissl stain

Ventrolateral periolivary cell groups, through their descending projections to the cochlear nucleus (CN) and local projections to principal nuclei of the superior olive, may participate in brainstem mechanisms mediating such tasks as signal detection in noisy environments and sound localization. Understanding the function of these cell groups can be improved by increased knowledge of the organization of their synaptic inputs in relation to their cellular characteristics. Immunocytochemistry for PEP-19 (a putative calcium binding protein) reveals four patterns of immunolabeling within the ventrolateral periolivary region. Three of the patterns, which have distinct fiber and punctate labeling characteristics, help to define three subdivisions of the lateral nucleus of the trapezoid body (LNTB). The fourth pattern defines two other nuclei, the anterolateral periolivary nucleus (rostral) and the posterior periolivary nucleus (caudal), which display many immunoreactive cell bodies but little fiber and punctate labeling. One of the subdivisions of the LNTB contains large PEP-19 immunolabeled puncta arranged in pericellular nests. Analysis of Nissl-stained sections reveals a neuronal population that resembles globular cells of the ventral cochlear nucleus (VCN) and which colocalizes with pericellular nests of large immunolabeled puncta. Cell counts reveal that roughly 10,000 neurons constitute the cat ventrolateral periolivary region, 9,000 of which are found in the LNTB. Three-dimensional reconstructions of auditory brainstem nuclei clarify the complex spatial relationships among these structures. © 1996 Wiley-Liss, Inc.     

螺旋CT仿真内窥镜对鼻腔鼻窦占位性病变的研究

目的:探讨螺旋CT仿真内窥镜对鼻腔鼻窦占位性病变的显示能力和临床应用价值. 方法:收集临床疑为鼻部占位病变的患者30例60侧鼻腔,分别进行CT仿真内窥镜检查(CTVE)、硬管内窥镜检查(RE),将两种检查方法所得显示结果进行对比研究,并利用Wilconxon W test 和X test进行统计分析.结果:CTVE与RE对鼻腔解剖结构和占位性病变的显示有良好的一致性,可完整显示鼻腔内大部分未受侵犯的结构及大的病变,但无法显示粘膜和病变的颜色,有时会遗漏较小的病变. CTVE较RE更好地显示鼻窦的解剖结构和鼻窦内的占位性病变而不需要破坏窦壁. 结论:CTVE的影像与RE相似,同时具有操作简便、无创性、多入路方式及多观察方向的特点.在鼻腔病变的诊断上,CTVE可作为RE一种补充手段;CTVE对鼻窦病变的诊断较RE有明显优势,可作为一种主要手段应用于临床.     

超低剂量下不同迭代重建技术在肺动脉成像中的优化

目的 探讨不同迭代重建技术在超低剂量肺动脉成像中的应用价值。方法 对30例临床疑似肺动脉栓塞患者行CT肺动脉成像,扫描采用80 kV管电压并开启自动管电流调制技术,分别采用滤波反投影法(FBP)、iDOSE⁴、迭代模型重建(IMR)重建图像。采用5分制评价肺动脉主干及其分支的图像质量,测量计算图像噪声值、SNR、CNR,记录CT容积剂量指数(CTDIvol)、剂量长度乘积(DLP)、计算有效剂量(ED)。比较不同重建技术图像噪声、SNR、CNR及主观图像质量。结果 30例患者的平均体质量指数(BMI)为(25.12±2.48)kg/m²;平均CTDIvol为(0.78±0.28)mGy;平均DLP为(30.46±11.34)mGy·cm,平均ED为(0.43±0.16)mSv。IMR、iDOSE⁴、FBP图像噪声依次增高(P<0.05),SNR、CNR依次降低(P<0.05),CT值差异无统计学意义(P>0.05)。IMR、iDOSE⁴图像的主观评分显著高于FBP(P<0.05);IMR、iDOSE⁴图像可诊断率高于FBP(P<0.05),IMR图像优良率高于iDOSE⁴(P<0.05)。结论 采用80 kV联合IMR可保证肺动脉成像较高的图像质量,同时大大降低患者辐射剂量。