建立模拟功能状态下的下颌骨三维有限元模型

本文在三维影像重建和三维有限元分析技术的基础上，建立了正常人和颞下颌关节疾病患者正中咬合时下颌骨的三维有限元模型。下颌骨螺旋ＣＴ和有限元模型三维重建影像的几何相似性良好，加载方式符合生理状况，比较真实地反映和模拟了功能状态下颞下颌关节与牙合的受力情况。为对颞下颌关节在各种状况下的生物力学行为进行分析和研究创造了条件。     

Liver lesion detection,characterization, and effect on patient management: Comparison of single-phase spiral CT and current MR techniques

This study compares liver lesion detection, characterization, and effect on patient management between single-phase spiral CT and MRI using spoiled gradient echo (SGE), T2-weighted fat-suppressed spin echo, and serial post gadolinium SGE. All patients with suspected liver lesions who underwent spiral CT and MRI within a 1-month period between January 1993 and September 1996 were included in the study. Spiral CT and MRI were interpreted prospectively in a blinded fashion by separate individual experienced investigators, and lesion detection and characterization were determined. Confirmation was obtained by surgery (6 patients), biopsy (18 patients), imaging follow-up (36 patients), or combined reading of all imaging studies and clinical follow-up (29 patients). Effect on patient management was determined by combined chart review and interview of the patients' physicians and by retrospective clinical assessment performed by a surgical oncologist and medical oncologist separately. Eighty-nine patients were included in the study. Regarding true positive lesion detection, 295 and 519 lesions were detected on spiral CT and MR images, respectively, which was significantly different on a patient-by-patient basis (P < .001). More lesions were detected on MR than on spiral CT in 44 of 89 patients (49.4%), and 11 of these 44 patients had lesions shown on MRI in whom no lesions were apparent on CT images. No patients had true positive lesions shown on spiral CT that were not shown on MRI. Regarding lesion characterization, 129 and 466 lesions were characterized on spiral CT and MRI images, respectively, which was significantly different on a patient-by-patient basis (P < .001). More lesions were characterized on MR than CT images in 67 patients (75.3%). Regarding effect on patient management, chart review with physician interview demonstrated that findings on MRI provided information that altered patient management as compared with findings on spiral CT in 57 patients. Retrospective clinical evaluation by the surgical and medical oncologist showed that MRI was considered to have a greater effect on patient management than spiral CT in 58 and 55 patients, respectively. Comparing current MRI technique to single-phase spiral CT, MRI detected more lesions in 49.4% and characterized more lesions in 75.3% of patients investigated for focal liver disease. MRI had a greater effect on patient management in each of the three methods than singlephase spiral CT in more than 61% of patients.     

PET-CT在冠心病中应用价值的研究进展

利用PET—CT研究冠状动脉硬化性心脏病(Coronary artcry disease CAD)目前罕见报道：．单纯利用正电子发射断层显像(Positron emission tomography PET)对CAD的研究在国外已经取得了一定的进展。取得了一些经验，国内只有零星的报道；尚未开展比较系统的、规模的、符合我国实际特点的研究。多层螺旋CT(Muti-slices spiral computed     

Adenovirus-mediated human β-nerve growth factor gene transfer has a protective effect on cochlear spiral ganglion after blast exposure

Objective：To study whether adenovirus-mediated human β-nerve growth factor （Ad-hNGFβ） gene has any protective effect on blast hearing impairment. Methods：Deafness was induced by blast exposure （172.0 dB） in 30 healthy guinea pigs. On day 7 of blast exposure, Ad-hNGFβ was infused into the perilymphatic space of 20 animals as the study group （hNGFβ group）, and artificial perilymph fluid （APF） was infused into the perilymphatic space of the other 10 animals as the control group. At weeks 1, 4 and 8 after blast exposure, the animals were sacrificed and the cochleae were removed for immunohistochemical and HE stainings. Results： Expression of Ad-hNGFβ protein was detected in each turn of the cochlea at the 1st week, with almost equal intensity in all turns. At the 4th week, the reactive intensity of the expression of Ad-hNGFβ protein decreased. At the 8th week, no expression was detectable. The results of HE staining showed that the amount of spiral ganglions in hNGFβ group was significantly greater than that of the control group at week 4 （P〈0.01）. Conclusion： Ad-hNGFβ can be expressed at a high level and for a relatively long period in the blast impaired cochlea, suggesting that Ad-hNGFβ has a protective effect on cochlear spiral ganglion cells after blast exposure and the efficient gene transfer into cochlea had been achieved without toxicity.     

SCTA在微小脑动脉瘤诊断中的应用

目的 探讨螺旋CT血管造影（SCTA）在直径小于10mm的脑动脉瘤诊断中的临床应用和价值。方法 选择12例直径小于10mm的脑动脉瘤患，进行SCTA，DSA或MRA检查，SCTA成像技术为表面遮盖法（SSD）和最大密度投影法（MIP）。结果 12例微小脑动脉瘤患术前均准确定性，定位，全部经神经外科手术证实。结论 SCTA是一种无创伤性血管成像方法，在诊断脑动脉瘤方面，具有分辨率高，快速，准确，经济等优点，可为临床诊断与治疗提供更多的信息。     

Cystic duct and Heister's "valves"

The anatomy and physiology of the cystic duct have been relatively neglected by anatomists and the function of the spiral mucosal folds or "valves" of Heister, first described in 1732, remains obscure. The gross and microscopic anatomy of the cystic duct is reviewed together with results from laboratory investigations into the function of the cystic duct and its spirally arranged folds. The duct and spiral folds contain muscle fibers responsive to pharmacologic, hormonal, and neural stimuli. There is, however, no convincing evidence of a discrete muscular sphincter within the duct. Although the cystic duct is unlikely to play a major role in gallbladder filling and emptying, it appears to function as more than a passive conduit. Coordinated, graded muscular activity in the cystic duct in response to hormonal and neural stimuli may facilitate gallbladder emptying. The principal function of the internal spiral folds that are found in man and other animals may be to preserve patency of this narrow, tortuous tube rather than to regulate bile flow.     

利用CT扫描及CAD技术建立腰椎活动节段的有限元模型

目的 :探讨腰椎活动节段有限元模型的建立。方法 :选取一正常自愿者L4～L5节段为研究对象 ,通过CT扫描、图像数字化处理及计算机辅助设计建立了腰椎活动节段的有限元模型 ,通过Super SAP有限元分析软件包对模型进行了应力分析。结果 :建立了L4～L5活动节段的有限元模型 ,并分析了生理载荷下腰椎活动节段不同组成部分的应力分布。结论 :为腰椎活动节段有限元模型的建立提供了一种简便、准确的方法 ,为分析和研究该模型在各种情况下的生物力学表现创造了条件     

肝外胆管梗阻病变MSCT曲面重建胆管成像与MRCP的比较研究

目的比较多层螺旋CT（MSCT）曲面重建（CPR）胆管成像与磁共振胰胆管成像（MRCP）对肝外胆管梗阻病变的诊断价值。方法66例经B超检查提示有肝外胆管梗阻病变的患者，采用单次激发快速自旋回波（SSFSE）序列，行MRCP检查，同期采用10mm层厚层距，使用血管对比剂，行MSCT增强扫描，将门静脉期图像采用2．5mm层厚、1．25mm层距重建，获得轴面源像（ASI），数据传输至图像工作站，作CPR胆管成像。比较CPR胆管成像、MRCP对肝外胆管梗阻病变的定位、定性诊断价值。结果CPR胆管成像、MRCP成功率为100％；CPR胆管成像、MRCP均对肝外胆管梗阻部位做出明确诊断，定位诊断率为100％；CPR胆管成像、MRCP定性诊断率分别为95．5％和80．9％。结论CPR胆管成像、MRCP对肝外胆管梗阻病变均能明确定位，CPR胆管成像定性诊断率明显高于MRCP，CPR胆管成像显示胆管及其周围病变与扩张胆管的关系更直观。     

应用多层螺旋CT对耳硬化症的术前评估价值

目的:评估MDCT在术前耳硬化症诊断中的作用。方法:收集经临床证实为耳硬化症、且CT扫描采用螺旋扫描病例共18例,采集的数据传输到4.1工作站,进行多平面重建。结果:18例共36耳显示异常:单独前庭窗异常18耳,表现为前庭窗扩大或狭小,周围骨质密度降低或镫骨底板板密度增高;前庭窗及蜗窗同时受累共8耳;主要累及耳蜗周围迷路骨质10耳,表现为耳蜗骨迷路边缘不整,呈条片状密度减低或双环征。MPR交互重建充分显示了所有重要解剖结构的位置、形态:其中3耳为颈静脉球高位。结论:MDCT可以正确显示耳硬化症病灶的细微改变,提供详细的术前诊断信息;结合MPR技术可全面观察病变范围,并充分显示颞骨内重要解剖结构的位置和形态。对于手术方案的设计、防止手术并发症和提高疗效等具有重要意义。