3．0T磁共振成像在腹部伪影的研究

目的：对3．0T磁共振成像（MRI）在腹部伪影产生的原因、表现和抑制方法进行研究。方法：收集40例腹部经GE Signa EXCITE HD 3．0T磁共振扫描产生伪影的图像进行分析。结果：3．0T MRI在腹部伪影主要是：化学位移伪影、ASSET伪影、电介质伪影、磁化率伪影、运动伪影和带状伪影。结论：认识3．0T伪影在腹部的特性，了解伪影产生的原因能够有针对性地选择抑制技术，提高图像质量。     

磁共振图像伪影的产生机理及其解决办法的研究

目的研究磁共振成像伪影产生的机理,探讨磁共振伪影处理的解决办法。方法回顾性分析了87例日立0．3T、GE1．5T、GE3．0T磁共振扫描仪的图像伪影。结果磁共振常见的儿种伪影主要有：射频伪影、梯度伪影、运动伪影、化学位移伪影、卷摺伪影及金属伪影。结论了解磁共振图像伪影的产生原因,寻找解决办法,对改善图像质量,提高诊断率具有重要意义。     

介绍一种消除颅脑MRI运动伪影的简易方法

目的：探索一种能有效抑制和消除颅脑MRI运动伪影产生的方法，以提高图像质量和工作效率。方法：利用包装CT管球的海绵．设计并制作了2cm×7．5cm×22cm，3cm×7．5cm×22cm，4cm×7．5cm×22cm等3种规格的海绵垫，配合使用颅脑正交线圈进行颅脑MRI检查。结果：采用“加垫法”行颅脑MRI检查2638例。其中，一次性扫描成功2633例（占99．81％），失败5例（占0．19％）；在扫描失败的5例患者中，第2次扫描时配合使用医用绷带成功4例，失败1例。结论：采用“加垫法”行常规颅脑MRI扫描，方法简单、可靠，可有效抑制和消除运动伪影的产生，提高图像质量和工作效率。     

螺旋桨扫描技术在消除头部MRI伪影的应用

目的：探讨螺旋桨扫描技术在消除头部MRI扫描时运动或（和）金属伪影的，临床应用价值。方法：收集我院2006年4～11月颅脑MRI检查患者，检查中出现躁动不合作者39例和18例口腔有固定金属异物行头颅MRI检查引起的磁敏感伪影的患者，应用PROPELLER技术进行T2WI和（或）扩散加权成像（DWI），并与常规T2WI图像进行对比分析。结果：39例患者的常规聊显示因运动产生的伪影，导致图像质量降低，无法达到诊断要求；采用PROPELLER T2WI均显著消除伪影的影响，病变显示清晰，达到诊断要求；18例因固定义齿常规MRI扫描时产生磁敏感伪影，采用PROPELLERDWI技术后均明显消除干扰伪影。获得了具有诊断价值的图像。结论：应用PROPEUJER T2WI、DWI技术，明显消除患者因运动或金属异物造成的伪影，可获得满意的、分辨率高、无伪影、具有临床诊断价值的理想图像。     

螺旋桨技术消除颅脑磁共振图像伪影的临床价值探讨

目的：探讨螺旋桨（PROPELLER）技术在颅脑磁共振成像中消除伪影的临床应用价值。方法：临床检查中出现躁动不配合或口腔内有固定金属异常的患者86例,使用GESignaHD1．5T高场双梯度磁共振扫描仪行PROP删I和（或）PROP-DWI以及常规FSE—RWI和（或）EPI—DWI轴位扫描。由3位高年资的影像科大夫对其图像质量进行评价,采用统计学,检验,分析图像的伪影和优质片率状况。结果：使用PROP-T22WI和PROP—DWI扫描序列比采用常规FSE—T2WI和EPI—DWI扫描序列所获得图像的运动及其他伪影明显减少（扩检验,P〈0．01）,优质图像的百分率明显提高（X2检验,P〈0．01）,颅内病灶显示更清晰。结论：PROPELLER—MRI解决了显著头动患者的运动伪影以及金属异物造成的磁敏感伪影,可重建成分辨率高、对比度好、无运动及磁敏感伪影的理想MR图像,具有较高的临床实用价值。     

颈椎钛合金固定术后MRI优化扫描

目的：探讨颈椎钛合金术后MRI扫描参数的优化,以降低磁化率伪影。方法：提出以分组的方式,按照3级评分标准,对10例颈椎钛合金术后患者行MRI检查（5例前路固定,5例后路固定）,患者均行矢状位、轴位：T1,T2加权成像（T1WI,T2WI）。其中部分扫描改变频率编码方向,TE值,空间分辨率,序列进行对比。分别对各组图像中磁化率伪影大小进行评判。结果：伪影在T1、T2加权像均呈低信号,其边缘分界线呈高信号;频率编码方向与钛合金长轴主轴平行时产生的伪影小于两者垂直时;TE取值越小,伪影越轻微;分辨率越高,伪影越轻微;梯度回波伪影比快速自选回波伪影严重。结论：在不增加病人风险的前提下,选择合适的扫描序列,合理优化扫描参数,可以有效降低磁化率伪影。     

磁共振成像的伪影分析与扫描技术处理

在磁共振扫描或信息处理过程中，由于某一种或几种原因出现了一些人体本身不存在的致使图像质量下降的影像，这就是所谓的磁共振成像的伪影。与其它影像技术相比，ＭＲＩ是出现伪影最多的一种影像技术。常见的几种伪影归纳如下：（１）卷褶伪影；（２）运动伪影；（３）金属伪影；（４）化学位移伪影；（５）部分容积效应伪影。本文拟对伪影产生的原因以及各种伪影的图像特征进行分析，以期有效地限制、抑制以至消除伪影，提高图像质量。一、卷褶伪影图像特征：扫描视野外的解剖部位的部分影像移位或翻转后重叠于扫描视野内的图像上。它常出…     

对MR产生伪影的改进

伪影是指MR成像过程中，由于各种原因所致，在成像过程中所显示出来的不是组织内存在的影像称伪影。伪影的产生严重影响图像质量，影响诊断，有时会出现误诊或漏诊。根据伪影产生的原因大致可分为：设备伪影；金属伪影；运动伪影。     

多层螺旋CT超高分辨率扫描在显示窦口鼻道复合体中的应用价值研究

目的探讨多层螺旋CT超高分辨率扫描及重建技术在显示窦口鼻道复合体解剖变异与相关病变中的应用价值。方法扫描模式UHRCT6mm×0．75mm,螺距0．9,FOV200mm,层厚2mm、层距1mm重叠重建。对1272例患者采用超高分辨率横轴扫描后MPR重建冠状图像及直接冠状位扫描随机分组：（1）MPR660例;（2）直接冠扫612例。两组图像分析对显示OMC的解剖、相关病变及图像内伪影干扰进行评估、比对。结果1272例患者中1088例显示变异、病变,占85％;MPR组与直接冠扫组中有假牙与无假牙无统计学意义（P〉0．05）,具有可比性;MPR组图像中有伪影显示33例（5％）,少于直接冠扫组中有伪影151例（24．67％）,差异有统计学意义（P〈0．01）。结论本研究解决了特殊情况下不能做冠状扫描患者的问题,在避免了假牙伪影干扰的同时,保证图像质量,达到充分显示OMC变异及相关病变的目的,为临床提供重要影像学依据。     

PET／CT图像基于CT衰减校正伪影的实验研究

目的：研究不同浓度泛影葡胺溶液在不同CT扫描条件下对PET／CT图像质量的影响。方法：向5个乳胶容器中分别注入体积分数为5％、10％、15％、20％和40％的1：7服泛影葡胺溶液，依次将其密闭置于圆柱形水模内进行PET／CT成像。利用CT扫描数据对PET图像进行衰减校正，并比较不同管电压CT扫描条件下PET图像的差异。结果：体积分数为15％、20％和40％的泛影葡胺充盈区在经CT衰减校正的PET图像上表现为高浓聚伪影．标准摄取值比本底均有不同程度的升高，而体积分数为5％、10％的泛影葡胺充盈区则无明显伪影，反映了随着泛影葡胺浓度的升高CT衰减校正伪影随之增强；对于体积分数为40％的口服泛影葡胺溶液，随着CT扫描所使用的管电压的升高．经CT衰减校正的PET图像上的伪影随之减弱．标准摄取值降低。结论：体积分数大于15％的泛影葡胺溶液在PET／CT成像中标准摄取值升高，图像表现出伪影；PET／CT成像中CT扫描所采用的管电压越高，高浓度泛影葡胺溶液产生的伪影越弱。     

新型主动脉旁反搏装置在小尾寒羊的初步实验研究

目的通过急性心衰动物辅助实验验证主动脉旁反搏装置（PACD）的辅助效果。方法随机选择健康成年8只小尾寒羊为研究对象,体重（44．9±2．5）kg,雌雄不限。自行设计并制作的PACD,其主体为一血囊通过一无瓣膜的人工血管连接至实验动物的降主动脉。气囊连接至IABP控制台,通过充、放气提供反搏动力。结扎前降支和（或）回旋支分支建立急性心衰模型。应用生理记录仪、连续心排量仪等连续采集反搏前后各血流动力学指标。比较心衰动物反搏前后各血流动力学变化,以评估PACD的循环辅助效果。结果结扎冠状动脉后心衰模型建立成功：心输出量（CO）、平均动脉压（MAP）及左室外功（LVEW）分别显著下降了17．6％（P〈0．01）,27．7％（〈0．01）,48．8％（P〈0．01）,肺毛细血管楔压（PCWP）显著增加了57．7％（P〈0．01）。PACD辅助后,CO及LVEW分别增加了6．3％（P〈0．01）,16．0％（P〈0．01）。平均舒张期主动脉压（MADP）及心内膜活力比率（EVR）分别现在增加了19．4％（P〈0．01）,39．5％（P〈0．01）。辅助后,心脏的血液灌注明显改善：平均舒张期冠脉左主干流量（MDLMF）及冠状静脉窦回心血量（CSF）分别增加了14．0％（P〈0．01）,11．6％（P〈0．01）。结论在急性心衰动物中,PACD显著增加了MADP、LADF及冠脉回心血量,提供了显著的辅助效果,因此有望给难治性心衰患者提供长期、安全、有效的循环辅助。     

The pattern of cardiac diseases at the cardiac clinic of jimma university specialised hospital, South west ethiopia

Background

Rheumatic heart disease is the commonest cardiac disease in most sub-Saharan African countries, followed by hypertensive heart disease which is rising along with the other non-communicable diseases. However the pattern in our setting is not known. This study aimed to determine the pattern of cardiac diseases among adult patients on follow-up at the cardiac follow-up clinic of Jimma University Specialized Hospital.

Methods

A cross-sectional study was conducted on cardiac patients who are newly enrolled to the cardiac follow up clinic of Jimma university specialized hospital during a five year period from 2003 to 2008. Out of the total 837 cases that were newly enrolled to the clinic in the five year period, 781 patients who had complete record about etiologic diagnosis were included in the study. The data were collected using structured record review checklist. The collected data were then analyzed using SPSS for windows version 12.0.

Results

Rheumatic heart disease was the diagnosis in 256 (32.8%) of the cardiac cases on follow-up followed by hypertensive heart disease and cardiomyopathy accounting for 189 (24.2%) and 158 (20.2%) of cases, respectively. Among Rheumatic heart disease patients; male to female ratio was 0.86:1 and the mean age was 31.4 years. One hundred ninety three (75.4%) of the cases with rheumatic heart disease had echocardiographic report that showed valve(s) involvements of pure MS in 99 (51.3%) and combined MS, MR in 49 (25.4%). Overall, hypertension contributed for a total of 241 (30.9%) of cardiac patients that included 189 (24.2%) hypertensive heart disease and 52 (6.7%) as one major risk factor for ischemic heart disease.

Conclusion

Rheumatic, hypertensive and cardiomyopathic heart diseases accounted for more than three-quarters of cardiac diseases in the study population. This study highlighted the need for further study to determine the burden at community setting.     

Radionuclide ventriculography in severely underweight anorexia nervosa patients before and during refeeding therapy

Congestive heart failure is a well-recognized complication of refeeding therapy in underweight patients with anorexia nervosa but there are few data describing cardiac function during the critical refeeding period. This prospective study examined left ventricular function with conventional electrocardiographic-gated radionuclide ventriculography (RVG) in severely underweight anorexia nervosa patients both before and during refeeding therapy. Eight patients underwent rest and exercise RVG at admission and after regaining approximately 5% to 10% of their ideal body weight. With the admission study serving as a control, the left ventricular ejection fraction and regional wall motion analysis were analyzed before and after refeeding and weight gain. Resting left ventricular ejection fractions were not significantly different between the first and second RVGs (64 +/- 11% vs. 62 +/- 8%, respectively; P greater than .05). Likewise, the left ventricular ejection fraction with maximal exercise did not significantly differ when comparing the first or the second RVG (74 +/- 10% vs. 72 +/- 8%, P greater than .05). During the baseline RVG, the left ventricular ejection fraction increased from 64 +/- 11% (rest) to 74 +/- 10% (maximal exercise) (P less than .001). During the second RVG, the ejection fraction increased from 62 +/- 8% (rest) to 72 +/- 8% (maximal exercise) (P = .003). However, the left ventricular exercise ejection fraction in the second RVG in one patient increased only by one absolute percentage point. Four of the eight patients had regional wall motion abnormalities detected during resting and/or exercise RVG. Abnormal cardiac function occurs in asymptomatic patients with anorexia nervosa undergoing refeeding therapy.     

68例应征青年心脏杂音临床分析

目的探讨应征青年心脏杂音与器质性心脏病的相关性。方法选择听诊有心脏杂音的应征青年68例,运用超声心动图检测其心脏结构及血液流动的改变。结果经超声心动图检出有相应瓣膜返流46例(67.6%)、左室假腱索11例(16.2%)、房间隔缺损3例(4.4%),总检出率88.2%,淘汰率27.9%;在边缘状态性心脏杂音24例中,相应瓣膜返流21例(87.5%)、左室假腱索3例(12.5),检出率100%,淘汰率66.7%。结论常规心脏听诊与超声心动图检查相结合是客观评价心脏杂音性质的理想方法 ,适合于各类健康体检对心脏杂音性质的判断。     

Prognosis for the fetus with congenital heart defects in the era of modern diagnostics and therapeutics

BACKGROUND: Prenatal detection of structural heart diseases and rhythm disturbance has become possible using echocardiography. Authors have already documented the high diagnostic accuracy of intrauterin diagnosis of heart diseases in our country as well. AIM OF THIS STUDY: To examine the prognosis of fetal cardiac diseases diagnosed by echocardiography in the institute between 1985-2001. METHODS: The prognosis of 223 (6.3%) cardiac anomalies found in 3468 fetal echocardiograms was assessed by postnatal echo/surgery/or autopsy. RESULTS: The authors detected cardiac anomalies in 153, rhythm disturbance in 70 fetuses. They could follow (mean 4.2 yrs) the 83% of patients by postnatal echo/surgery or autopsy. They lost 46 pts (36%) by elective termination, intrauterine death, or during the postnatal period. 83% of these pts had hypoplastic left heart syndrome, fibroeleastosis, or aortic stenosis. Right heart anomalies (tetralogy of Fallot, critical pulmonary stenosis etc.) showed good prognosis with early surgical or catheter intervention. Isolated fetal supraventricular tachycardias can be successfully treated prenatally, and fetal complete heart block by emergency postnatal permanent pacemaker implantation. CONCLUSIONS: Fetal echocardiography must be considered in our country also such a method which can influence the natural history of fetal heart diseases. The result of infant cardiac surgery also dramatically improved, so we think this knowledge is very important during the counselling.     

多排螺旋CT肋骨三维重建呼吸运动伪影与肋骨骨折鉴别诊断

目的：探讨64排螺旋CT肋骨三维重建检查中呼吸运动伪影产生的原因及表现。方法：对56例存在呼吸运动伪影的肋骨三维重建图像进行分析,运用三维重建技术容积重建（volume reconstruction,VR）、多平面重建（multiple plannar reconstruction,MPR）等分析呼吸运动伪影的表现。结果：56例患者中．肋骨三维重建检查共发现呼吸运动伪影的肋骨269处．肋骨骨折215处,VR和MPR上呼吸运动伪影都有特异的表现,VR图像上表现为平行于横断面的“骨折线”,且大多有“错位”、边缘模糊：MPR上呼吸运动伪影表现为“断端”两侧的肋骨相互嵌插,并且断端骨皮质逐渐变薄,没有明确的断端。结论：呼吸运动伪影的产生是由于患者的精神紧张、呼吸急促等,三维重建可以鉴别呼吸运动伪影与肋骨骨折,对减少误诊具有重要的作用。     

Micromax 1型等3种便携式超声与常规超声心动图对老年心脏病住院患者心脏检查的对比研究

评价了3种便携式超声(Hand-carried ultrasound,HCU)在老年心脏病住院患者的临床应用价值。以常规超声心动图(comprehensive echo-cardiography,CE)为评判标准,对401例老年心脏病住院患者进行左室、左房、主动脉根部内径,室间隔与左室后壁厚度,二、三尖瓣反流的检测。两种技术在心脏腔径大小及左室射血分数的检测上无明显差异,关于室壁节段运动异常评价HCU相对于CE的检出率为92.15%。对于检测二尖瓣反流,三尖瓣反流两种技术均具有较好的符合率(符合率分别为93%与91.4%)。HCU对于老年心脏病诊断及病情监测具有一定实用性。     

Cardiac responses of rats submitted to postnatal protein restriction

Undernutrition during critical stages of development and childhood has important effects on cardiovascular homeostasis. The present study was undertaken to evaluate the in vivo and ex vivo cardiac function of rats submitted to postnatal protein restriction. Male Wistar rats (28 days old) were fed a regular (20%) or low-protein (6%) diet over 5 weeks. After this period, cardiac function was analyzed by echocardiography and isolated heart preparation. Furthermore, the density of cardiac noradrenergic fibers and hematological profile were evaluated. We found that malnourished rats exhibited elevated arterial blood pressure, increased fractional shortening (echocardiography), increased systolic tension, increased ±dT/dt (isolated heart technique), impaired diastolic function characterized by a slight increase in the left ventricular end-diastolic diameter (echocardiography) and decreased diastolic tension (isolated heart technique), and cardiac hypertrophy evidenced by augmentation of the posterior left ventricular wall and discrete hematological changes. In addition, malnourished rats exhibited increased noradrenergic fiber density in their hearts (0.08% ± 0.02% area in control rats vs. 0.17% ± 0.03% area in malnourished rats). Our current data demonstrate that postnatal protein restriction causes cardiac adaptation characterized by an early overworking heart. This is at least in part mediated by an increase in the efferent sympathetic fibers to the heart. These findings provide important information for efforts to prevent and manage the consequences of undernutrition in the human population.     

选择性三野淋巴结清扫治疗胸中下段食管癌

目的探讨经左胸切口选择性三野淋巴结清扫术治疗胸中下段食管癌手术方法及淋巴结清扫效果。方法2005年6月至2009年3月手术治疗胸中下段食管癌213例,采用左胸第6肋间切口,对纵隔左右两侧同时进行淋巴清扫,并切除左右两侧纵隔胸膜,腹野清扫1—5组,7—12a组,16al、19组淋巴结,颈野仅做食管系膜内淋巴结摘除。结果213例共检出淋巴结14197枚,平均（66．65±24．73）枚;淋巴结转移105例,转移率49．29％（105／213）,转移淋巴结423枚,转移度2．97％（423／14197）,术后病理检查食管标本上下切缘均无癌残留。手术时间2．92～4．67（3．37±0．42）h,术中术后输红细胞0—6^u（1．08±0．93）^u;术中术后输血浆0—1400（103．77±184．89）ml;住院时间14—39（17．64±4．12）d。无喉返神经损伤,无吻合口瘘。1例死于呼吸衰竭,死亡率0．04％（1／213）。结论经左胸第6肋间切1：3,扩大了标准三野清扫术中的胸野淋巴结清扫范围,缩小了颈野淋巴结清扫范围,上腹部和胃周围淋巴结清扫达到选择性队水平,手术创伤小,术后并发症少。     

氯普鲁卡因用于蛛网膜下腔麻醉的临床观察

目的 观察国产氯普鲁卡因腰麻的临床效果。方法 40例患者经L3-4脊间隙行腰麻穿刺,向蛛网膜下间隙注入(针斜面向尾)氯普鲁卡因合剂(2.5%氯普鲁卡因1.2 ml+10%葡萄糖0.5 m l+3%麻黄碱0.5 ml)2.2ml/30~40秒。结果①麻醉起效时间、胸10无痛时间、双下肢不能抬起时间、达到最高阻滞平面的时间,分别为(21.69±9.43)sec、(3.56±0.77)min、(3.56±0.64)m in和(7.94±1.02)min;最高阻滞平面为胸5.03±1.27;麻醉消退至胸12开始疼痛时间、双下肢能抬起时间、麻醉完全消失时间,分别为(56.67±8.47)min、(67.94±12.85)m in和(76.95±17.17)min。②术中无患者诉疼痛。③麻醉后未出现低血压反应。心率相对稳定。SpO2正常。④麻醉后未出现恶心、呕吐。⑤麻醉后及其3天内未见任何精神神经系统不良反应。⑥2.5%氯普鲁卡因pH为6.38±0.55,比重为1.012±0.003,其腰麻合剂pH为6.12±0.46,比重为1.012±0.003。结论 氯普鲁卡因可安全有效地用于腰麻。