21天头低位卧床对肺弥散功能的影响

目的　探讨 2 1d - 6°头低位卧床 (HDT - 6°)对肺弥散功能的影响 ,并对其变化的相关因素进行分析 ,为地面模拟失重及航天飞行医学监督提供有关医学参考。　方法　采用Vmax 2 2LV肺功能仪和 6 2 0 0肺功能仪 ,对 16名健康男性受试者卧床前、后及卧床不同时间反映肺弥散功能的指标 [弥散容量 (DLco)、弥散常数 (Kco)、肺泡容量 (VA) ]以及反映肺内气体分布的指标和肺血容量分别进行了测试。　结果　与卧床前平卧位相比 ,在卧床开始时 ,DLco、Kco均增加 ,从卧床的第 3天起至恢复期第 1天 ,DLco、Kco显著减少 ,恢复期第 3天尚未恢复至卧床前水平 ;头低位卧床期间VA显著减少。Kco在卧床中的变化趋势与DLco一致 ,但变化率高于DLco ,主要是由于头低位卧床期间VA、肺血容量的显著减少以及肺内吸入气的分布不均有关 ,同时肺泡 毛细血管膜的变化也是不容忽视的因素。　结论　头低位卧床肺弥散功能下降与肺毛细血管血量的减少、肺泡容量下降 ,以及通气血流分布不均和潜在性的肺间质水肿导致膜弥散下降有关 ,在头低位卧床模拟失重的医学监督应考虑肺弥散功能的变化。     

肺弥散功能指标DLco,Kco在肺疾病诊断中应用价值探讨

为了进一步了解各关因素对肺散功能ＤＬｃｏ及Ｋｃｏ测定的影响以及二者测定在航天医学中应用的可行性。本实验采用一口法对１２０例健康人和７６例肺疾病患者进行了肺弥散功能和常规肺功能测定，并作了对比分析。结果表明，健康人ＤＬｃｏ，Ｋｃｏ均值随年龄增加而递减。     

糖尿病患者的肺功能变化及其临床意义

用CHEST-25型肺功能仪测定49例糖尿病患者和37名正常人的肺容量、流速容量曲线及肺弥教功能．结果示糖尿病患者的VC、VC%、FEV1%、MVV、MVV%、RV、FRC和TLC等与正常人接近，而DLco．DLco%、DLco／VA和DLco／VA%明显降低，病程在6年以上和伴有其它并发症者下降更显著．1型糖尿病患者和空腹血糖及糖化血红蛋白浓度高者弥敬功能也较差。糖尿病患者弥散功能障碍可能与糖尿病性肺部徽血管病变和蛋白的非尊糖基化有关。     

肺弥散量测定方法评估急进高原后高山反应

27名健康者从海拔2260m快速进入海拔4700m高原进行了肺CO弥散量的测定，显示肺CO弥散量与急性高山病有某种程度相关。反应组10例和对照组17例相比，肺CO弥散量均随海拔的增高而增加，增加的幅度反应明显小于对照组。因此，认为人体进入高原后肺CO弥散代偿能力不足是发生急性高山病重要原因之一，利用肺DL-CO量测定评估人体对高原的适应性可作为预测急性高山病发生的一项客观指标。     

头低位-30°对肺功能的影响

目的研究短时间模拟失重对健康人肺功能的影响。方法采用头低位 - 30°模拟短期 ( 4 5min)失重 ,用体描箱对 1 2名健康男性分别于坐位、平卧位、头低位 1 0～ 1 5min ,头低位 45min测量了肺功能的各项指标 ,同时用彩超测量了肺动脉血流和右心功能。并进行了对比分析。结果随着体位由坐位、平卧位到头低位 ,肺通气量 (FVC ,FEV1 ,FEV1 % ,MVV)、肺容量 (VA ,IVC)逐渐减少 ,其中以MVV变化显著 (P <0 .0 0 0 )。而同时随体位变化肺弥散显著增加 ,DLCO(P <0 .0 0 1 ) ,KCO(P <0 .0 0 0 )。结论 -30°、45min头低位时 ,肺通气量、肺容量显著减少。肺弥散量明显增加 ,其中以肺血容量增加 ,肺血流的均匀分布为主要影响因素。     

充分血液透析对慢性肾功能衰竭患者肺弥散功能的影响

通过观察10例慢性肾功能不全血液透析患，在充分血液透析情况下的肺弥散功能、通气功能和肺容量，发现血液透析患的肺功能不能达到完全正常。达到充分透析的指标时．KT／V值的增加，未见肺弥散功能相应提高，两无相关性。     

旅居高原肺通气功能的动态变化

作者在不同的海拔高度对30例健康人肺通气功能、血氧饱和度(SO_2)及流速容量曲线(MEFV)做了较长时间的动态观察。结果发现:呼吸频率(RR)、潮气量(TV)和每分通气量(MV)均随海拔升高而升高,但SO_2却随海拔升高而下降。持续海拔5000米高原11周时SO_2呈上升趋势,但MV却减少,二者呈反向变化。因此、作者认为,肺通气对缺氧的代偿是非常有限的,它需要肺血灌注和弥散功能的改善以及氧运输、氧利用的密切配合。而SO_2和MV的反向变化以及血红蛋白(Hb)的提高可能是机体在器官水平上逐渐产生了对低氧适应的结果。作者还对随海拔升高高峰流速(PEFR)的逐渐增大以及等速容量(Visov)的增大进行了讨论。     

SARS对肺膜弥散量和肺毛细血管血量影响的临床研究

目的研究严重急性呼吸综合征(SARS)的肺弥散能力(DL)、肺泡毛细血管膜弥散能力(Dm)及肺泡毛细血管血容量(Vc)的变化,探讨肺弥散功能障碍的病理生理机制。方法SARS组(26例)及正常对照组12名,测定静息状态下不同氧分压下的DL,按照Roughton和Forster方法计算Dm和Vc。结果SARS组DLco显著低于对照组,A组Dm和、Vc显著低于对照组;肺部病变程度越重,肺弥散功能损害越重,残气容积(RV)低于或高于正常值者也增多。结论SARS患者不仅有Dm而且也有Vc的改变,Dm和Vc的测定对发现SARS肺病变有益,可以明确DL下降的原因及判断病变的程度,是肺弥散功能检查重要和敏感的指标。     

铀氧化物在人体模拟肺液中的溶解特性

目的 研究现场采集的不同粒径铀氧化物在人体模拟肺液和相关的缓冲体系中的溶解特性,方法 用Cascade采样器将氧化铀按粒径分级、观察不同粒径铀氧化物在模拟肺液和缓冲液中不同时间的累积溶解百分数。结果 小粒径铀氧化物在模拟肺液中的溶解度相对较高,且溶解速率随时间增加而增大。铀氧化物在HAc-NaAc体系中的溶解速率随酸度增加而加快,在碱性NH4OH－NH4Cl体系中溶解速率随碱性增加而加快。铀氧化物在Na2CO3溶液中易溶,在NaH2PO4-Na2HPO4体系中几乎不溶。结论 小粒径铀氧化物在模拟肺液中溶解度较高。铀氧化物易溶于酸性HAc-NaAc体系,碱性NH4OH－NH4Cl体系和Na2CO3溶液,不溶于NaH2PO4-Na2HPO4体系。     

健康人胸片的X线定量分析(附462例报告)

目的为了提高对健康人胸片的认识和积累资料.方法对462例6～102岁健康人的胸片28项指标进行了X线定量分析.结果代表心脏、大血管、胸廓及肺体积改变的各项观测指标,随年龄增长而发生不同程度的变化.结论各项观测指标符合健康人生理发展规律.     

Pulmonary complications of multimodality therapy for esophageal carcinoma

Thirty patients with cancer of the esophagus were treated with multimodality therapy. We studied the incidence of pulmonary complications in these patients. The value of chest radiographs and sequential measurements of carbon monoxide diffusing capacity (DLco) in predicting pulmonary toxicity was determined. Patients were divided into two groups, according to treatment. Patients in group I (n = 16) received two cycles of chemotherapy (bleomycin 15 units/m2, cisplatinum 120 mg/m2, vincristine 2 mg) and radiotherapy (50 Gy). Based on the presence of interstitial lesions on chest radiographs in five patients the incidence of pulmonary toxicity was 32%. In four of these five patients such an appearance was preceded by a drop in DLco: this was documented in 8 of the 16 patients. Nine patients of group I underwent esophagectomy and four (44%) developed adult respiratory distress syndrome (ARDS). In group II (n = 14) the tumor was resected without other treatment and four (29%) of these patients developed ARDS. The incidence of ARDS in both groups demonstrates that pulmonary complications are mainly related to surgical manipulation and to preexisting lung disease. Preoperative radiotherapy and chemotherapy may be associated factors. Sequential measurements of DLco are more sensitive for detecting pulmonary damage than chest radiographs and should be used to predict pulmonary toxicity.     

Helium-3 diffusion MR imaging of the human lung over multiple time scales

RATIONALE AND OBJECTIVES: Diffusion magnetic resonance imaging (MRI) with hyperpolarized (3)He gas is a powerful technique for probing the characteristics of the lung microstructure. A key parameter for this technique is the diffusion time, which is the period during which the atoms are allowed to diffuse within the lung for measurement of the signal attenuation. The relationship between diffusion time and the length scales that can be explored is discussed, and representative, preliminary results are presented from ongoing studies of the human lung for diffusion times ranging from milliseconds to several seconds. MATERIALS AND METHODS: (3)He diffusion MRI of the human lung was performed on a 1.5T Siemens Sonata scanner. Using gradient echo-based and stimulated echo-based techniques for short and medium-to-long diffusion times, respectively, measurements were performed for times ranging from 2 milliseconds to 6.5 seconds in two healthy subjects, a subject with subclinical chronic obstructive pulmonary disease and a subject with bronchopulmonary dysplasia. RESULTS: In healthy subjects, the apparent diffusion coefficient decreased by about 10-fold, from approximately 0.2 to 0.02 cm(2)/second, as the diffusion time increased from approximately 1 millisecond to 1 second. Results in subjects with disease suggest that measurements made at diffusion times substantially longer than 1 millisecond may provide improved sensitivity for detecting certain pathologic changes in the lung microstructure. CONCLUSIONS: With appropriately designed pulse sequences it is possible to explore the diffusion of hyperpolarized (3)He in the human lung over more than a 1,000-fold variation of the diffusion time. Such measurements provide a new opportunity for exploring and characterizing the microstructure of the healthy and diseased lung.     

Time-resolved three-dimensional pulmonary MR angiography and perfusion imaging with ultrashort repetition time

RATIONALE AND OBJECTIVES: The purpose of this study was to implement ultrafast, multiphase three-dimensional (3D) magnetic resonance (MR) angiography and perfusion imaging after bolus injection of contrast medium to generate preliminary validation of parameters in a pig model and to illustrate potential applications in patients with lung abnormalities. MATERIALS AND METHODS: Five healthy volunteers, five patients, and three pigs underwent rapid, time-resolved pulmonary MR angiography and perfusion imaging on a 1.5-T MR imager. All patients had undergone correlative computed tomographic or conventional angiography. The pulse sequence was a 3D spin-warp, gradient-echo acquisition with a repetition time of 1.6 msec and an echo time of 0.6 msec. Each 3D acquisition lasted 2-3 seconds, and 8-16 sequential measurements were made in each study. Artificial pulmonary emboli were generated in pigs with gelatin sponge. All patients had diseases of the pulmonary circulation (as confirmed with other studies). RESULTS: Multiphasic, time-resolved pulmonary parenchymal enhancement was demonstrated in all healthy subjects and animals. All segmental (n = 100) and subsegmental (n = 200) branches were identified in the healthy subjects. Perfusion deficits were clearly demonstrated in all pigs after gelatin embolization. Perfusion defects were identified in two patients with lung disease. Abnormalities of the pulmonary vasculature were clearly identified in the patient group. CONCLUSION: Dynamic time-resolved 3D pulmonary MR angiography and perfusion imaging is feasible in humans as well as in animals. Induced perfusion deficits are identifiable after artificial embolization in pigs. Combined pulmonary MR angiography and parenchymal (perfusion) imaging may improve evaluation of the pulmonary circulation in a variety of conditions.     

周围型肺癌对癌周肺灌注的影响:螺旋CT初步研究

目的 采用螺旋CT扫描技术，研究周围型肺癌癌周肺灌注表现。资料与方法 对32例肺内肿块患者行病灶最大面积层面同层动态增强扫描，获取时间．密度动态曲线。根据病理或临床诊断结果，将受试者分为两组：周围型肺癌组和良性病变组。计算患肺和健肺兴趣区的CT强化值(简称EV)，分别比较各组病例两肺间的EV及两组病例患肺间的EV差异。结果 (1)周围型肺癌组患肺EV值统计学上显著低于健肺(P=0．039)；(2)良性病变组患肺和健肺EV间无明显统计学差异(P=0．183)；(3)两组病例患肺间EV有显著性统计学差异(P=0．008)。结论 周围型肺癌癌周肺组织常有不同程度灌注低下。     

Pulmonary blood flow distribution in erect man in air and during breathhold diving

We used intravenously administered 99mTc-labelled macroaggregates and a gamma camera attached to a computer for measuring distribution of pulmonary blood flow per unit lung volume in eight healthy subjects sitting erect in air and also during breathhold diving to 1 or 10 m of depth. We measured distribution of perfusion in the supine position and substituted regional lung volume with regional perfusion in the supine for calculating regional perfusion per lung volume erect in air and during diving. The perfusion per unit lung increased rectilinearly down the lung in subjects below 30 years of age but decreased in the lowermost regions in older subjects. This decrease showed a strong correlation to closing capacity. An age-related decrease in transpulmonary pressure may influence both basal perfusion and closing capacity. During submersion, perfusion became equal in all regions with the exception of the lung apex which became hyperperfused. Close to the diaphragm, small inconsistent changes were noted. Redistribution was the same at surface (1 m of depth) with the lung volume being close to total lung capacity and at 10 m of depth when lung volume was compressed to functional residual capacity. During breathhold diving, high intrapulmonary blood volume and pressure became more important for blood flow distribution than gravity or lung volume, while differences in regional hypoxic vasoconstriction and in transpulmonary pressure seem to explain interindividual variation.     

Pulmonary diffusing capacity: assessment with oxygen-enhanced lung MR imaging preliminary findings

PURPOSE: To determine differences in the signal intensity (SI) time courses at oxygen-enhanced magnetic resonance (MR) lung imaging in healthy volunteers and patients with pulmonary diseases and to correlate these differences with pulmonary diffusing capacity. MATERIALS AND METHODS: Seventeen patients with pulmonary diseases and 11 healthy volunteers underwent oxygen-enhanced MR imaging while they breathed room air and 100% oxygen. A turbo spin-echo sequence with global or section-selective inversion pulses was used. For postprocessing, SI slope maps during the breathing of 100% oxygen were calculated. Mean SI slope and SI change values were compared with the diffusing capacity of the lung for carbon monoxide (DLCO). RESULTS: The SI slopes were significantly different for patients and volunteers (P < or = .05, Mann-Whitney U test). Linear correlations were detected between the DLCO and SI slopes for the section-selective inversion pulse (r(2) = 0.81) and the global inversion pulse (r(2) = 0.74). A lower correlation was associated with the SI change for the section-selective pulse (r(2) = 0.04; global pulse, r(2) = 0.81). Regional differences were seen in the SI slope and SI change maps. These differences correlated with findings on radiographs and computed tomographic scans. CONCLUSION: The SI slope during the breathing of 100% oxygen allows spatially resolved assessment of the pulmonary diffusion capacity.     

肺表面活性物质与体外循环术后肺损伤

肺表面活性物质的异常在许多疾病的发生、发展中起重要作用。实验证实，体外循环术后内源性肺表面活性物质各个组分均有不同程度的改变，并最统筹兼顾民为体外循环术后肺损伤的原因之一。现就肺表面活性物质与体外循环术后肺损伤的关系作一简要综述，并对利用外源性肺表面活性物质治疗体外循环术后肺损伤进行展望。     

系统性硬化症患者静息肺功能的变化

目的:比较分析系统性硬化症(SSc)患者有、无呼吸道症状等不同状态时静息肺功能的变化,以观察其不同阶段肺损害的程度.方法:选择临床确诊的SSc患者68例,男10例,女58例,平均年龄41.5岁,测定静息肺功能的变化.结果:无任何呼吸道症状组胸片异常占23.2%,弥散功能障碍高达91.1%,限制型通气功能障碍占42.3%,小气道功能障碍占56.8%.有呼吸道症状组胸片异常占66.7%.无呼吸道症状组和胸片正常组SSc患者实测值占预计值%均有2项均值(FEF_(25%～75%)和DLco)异常,而有呼吸道症状组和胸片异常组则分别有5项异常.四组均以DLco、FEF_(25%～75%)和PEF下降的发生率和下降幅度最大.各组FEV_1/EVC均在正常范围内.胸片正常组VC、TLC、FRC和DLco明显高于异常组.结论:SSc肺功能改变与呼吸系统症状和胸片异常改变有关,且早于呼吸系统症状出现和胸片异常改变前.弥散功能障碍和小气道病变是SSc早期肺功能改变.肢端型SSc亦有很高比例的肺功能损害.SSc早期存在代偿性肺气肿.