【作者】 张利华；

【导师】 王云华；

【作者基本信息】 中南大学 ， 影像医学与核医学， 2010， 硕士

【摘要】 目的通过对COPD患者行64层SCT低剂量深吸气末、深呼气末扫描,利用pulmo软件,并与临床肺功能检查(PFT)对照,探讨64层SCT低剂量双相扫描获得的密度、体积及像素指数各指标在COPD患者肺功能评价方面的应用价值。资料与方法对长治医学院附属和平医院及中南大学湘雅二医院2010年3月-2010年9月期间,部分住院及门诊的经临床肺功能检查确诊的COPD患者36例,男性19例,女性17例,年龄范围51岁-84岁,平均年龄65.5士12.3岁,进行64层SCT低剂量双相扫描。另对30例健康体检者(无任何心肺疾患且胸部CT检查正常),男18例,女12例,年龄范围50岁-75岁,平均年龄60.5±10.5岁,进行同样方法的CT扫描。两组研究对象均采用德国Siemens SOMATOM Sensation 64层SCT机进行深吸气末、深呼气末的全肺低剂量扫描。利用pulmo软件,按扫描层数将全肺等分为上、中、下三个肺区,分别测量和计算出COPD组与正常对照组的：(1)深吸气末、深呼气末上、中、下肺区及全肺的密度指标与体积指标：其中密度指标纳入研究的有：深吸气末密度(Din)、深呼气末密度(Dex)、密度差(Dex-Din)、密度比(Dex/Din)、密度变化百分比(Din-Dex)/Din,体积指标有：深吸气末体积(Vin)、深呼气末体积(Vex)、体积差(Vin-Vex)、体积比(Vex/Vin)、体积变化百分比(Vin-Vex)/Vin。(2)将深吸气末、深呼气末像素指数(PI)分为-1024～-960,-960～-910,-910～-800,-800～-700,-700～-400,5个阈值区域,计算出深吸气末、深呼气末各阂值区域的像素指数：深吸气末像素指数(Plin)、深呼气末像素指数(Plex)。(3)深吸气末、深呼气末上、中、下肺区及全肺的小于-910HU的像素指数各指标：PIin-910、PIex-9100、PIin-910-PIex-910、PIex-910/PIin-910、(PIin-910-PIex-910/PIin-910。所有COPD患者均在CT检查前后3天内完成PFT检查,PFT检查采用德国耶格公司的体积描记仪Master Lab(Jaeger, Gemrnay)测定肺通气功能,指标为第1秒用力肺活量的实测值与预计值的比值(FEV1%)及第1秒用力肺活量与用力肺活量的比值(FEV1/FVC)。另对其中的40例被检查者(包括20例COPD组及20例正常对照组)加做100mAs吸气末CT扫描,所有扫描结束后,由CT扫描机自动计算出每次扫描(包括50m As呼吸双相与100mAs单相)的容积CT剂量指数(computed tomography dose index, CTDIvol)和剂量长度乘积(dose-length product, DLP),计算并比较不同管电流及呼吸状态下的CT扫描辐射剂量,并由有经验的医师及技师各一人,对每幅图像进行阅片,评价不同扫描条件下每幅横断面影像的质量。应用SPSS17.0统计软件包进行数据统计,不同扫描条件下的的CTDIvol DLP的比较采用配对样本的t检验,不同扫描条件下的CT图像质量评价应用四格表的X2检验(Fisher确切概率法),CT各指标的两独立样本之间采用t检验,比较COPD组与正常组之间的差异性,利用Pearson相关分析来检验各CT指标与肺功能FEV1%、FEV1/FVC指标的相关性。结果1.50mAs呼吸双相扫描的CTDIVol之和、DLP之和与100mAs条件下单相扫描的相应指标比较,它们之间的差异均无统计学意义(p>0.05)；管电流使用100mAs吸气末、50mAs深吸气末、深呼气末的图像优良率分别为100%、97.5%、92.5%,它们之间的差异没有统计学意义(p>0.05)。2.COPD组与正常组比较,各肺区及全肺区的密度各指标差异均有统计意义(p<0.05或p<0.01)；各肺区的Vin差异无统计学意义(p>0.05),各肺区及全肺区的其余体积指标差异均有统计意义(p<0.05或p<0.01)；除PIin.910-PIex.910外,各肺区及全肺区的PI-910指标差异均有显著统计学意义(p<0.01)。3.正常组与COPD组比较,Plin在-960～-1024,-910～-960,-800～-910三个分区差异有显著统计意义(p<0.01),而Plex在各个分区差别均有显著统计意义(p<0.01)。4.PI-960～1024,PI-910～1024与FEVl%、FEV1/FVC有显著相关性(p<0.01),以PI-910～-1024相关性较佳。5.各CT指标中,所有呼气相指标与反映气流阻塞的FEV1%、FEV1/FVC均有良好的相关性,双相密度差值及各指标比值、变化百分比也与FEVl%、FEV1/FVC有良好的相关性(p<0.01)。结论1.应用64层SCT低剂量双相扫描所获得的容积数据与图像质量能够满足正常人及COPD患者肺功能评价的要求,可取代常规剂量下的64层SCT双相扫描肺功能检查。2.64层SCT低剂量双相扫描可用于评价正常人及COPD患者的肺功能状况,其中Dex.Vex.PI-910指标及Dex-Din及呼气末与吸气末各项指标比值、变化百分比为肺功能评价的有用指标(与FEVl%.FEVl/FVC两项指标均有较好的相关性),而PIex-910. PIex-910/PIin-910指标更有临床价值(与FEVl%.FEVl/FVC相关系数均达0.64以上)。更多还原

【Abstract】 ObjectiveThe patients with COPD were selected and underwent chest 64 slices SCT Low-dose scanning at full inspiration and full expiration, respectively.The total lung was measured by CT pulmo software and the indexes were contrasted with the PFT results.To explore the clinical value of the density,volume and pixel index from 64 slices SCT images in evaluation of pulmonary function of patients with COPD.Materials and MethodsBetween March 2010 and September 2010,36 COPD patients (COPD group) who are partial out-patient clinic and partial hospitalization from the heping Hospital of Changzhi medical college and the second xiangya Hospital of central south University were enrolled in this study.All the patients were underwent PFT and were essentially verified COPD. The patients included 19 males and 17 females ranging in age from 51 to 84,with an mean age of 65.5±12.3 years.All the patients were underwent PFT and 64 slices SCT within 3 days.30 healthy people (control group) were selected and 64 slices SCT chest scanning results were normal.The group included 18 males and 12 females ranging in age from 50 to 75,with an mean age of 60.5±10.5 years.The two groups were underwent chest 64 slices SCT (Siemens,Germanny) low-dose scanning at full inspiration and full expiration.After the scanning,the total lung was measured by CT pulmo software. The lung was divided into three equal regions. Measure and calculate the results of each region (include upper,middle,lower field and the total lung) respectively:(1)lung density at full inspiration and full expiration (Din,Dex), density difference (Dex-Din), density ratio (Dex/Din), density variation percentage (Din-Dex)/Din;lung volume at full inspiration and full expiration (Vin,Vex),volume difference (Vin-Vex), volume ratio (Vex/Vin), volume variation percentage (Vin-Vex)/Vin; (2)pixels indexes with five groups of-1024～-960,-960～-910,-910～-800,-800～-700,-700～-400.Ca-lculate the pixels indexes at full inspiration and full expiration (the PI value is the sum of the Pixels under-910HU), (PIin-910,Plex-910),PI-910 difference (PIin-910-PIex-910), PI-910ratio (PIex-910/PIin-910),PI-910 variation percentage (PIin-910-PIex-910)/PIin-910.Their pulmonary function were tested by Master Lab (Jaeger,Germany).The indexes were forced expiratory volume at the first second%pre (FEV1%) and ratio of the first second forced expiratory volume to forced vital capacity (FEV1/FVC). We selected 20 patients with COPD and 20 healthy people.All subjects were underwent 64 slices SCT scanning of the total lung at routine-dose with inspiration,extrally.When the scanning was finished,CT machine calculated computed tomography dose index(CTDIvol) and dose-length product(DLP) automatically. We compared radiation dose at different tube currents and different breath condition and invited a salty doctor and a salty technician to observe every image and evaluate the section image quality. The results were analyzed statistically by the SPSS 17.0. CTDI Vol and DLP at different scanning condition were tested by paired t-test.Image quality evaluation at different scanning condition was tested by X2 test. Compared with the CT indexes between the COPD group and the normal group by t-test and the CT indexes were analyzed the correlation with the FEVI%and FEV1/FVC by pearson correlation analysis..Results1. Compared with CTDIVol in single phase of 100 mAs and the sum of CTDIvoLin two phases at low-dose of 50mAs, the difference between them was not statistically significant (p>0.05).DLP was the same result. Section image fineness ration at 100mAs at inspiration，50mAs at full inspiration,50 mAs at full expiration was 100%、97.5%、92.5%,the difference between them was not statistically significant (p>0.05)2.Compared with density indexes of each region and the total lung in normal group and the case group,the difference between them was statistically significant (p<0.05 or p<0.01); the difference of lung volume at full inspiration at each region was not statistically significant(p>0.05); the difference of the other lung volume indexes at each region and the total lung was statistically significant (p<0.05或p0.01); the difference of the all PI-910 indexes except the PIin-910-PIex.910 was statistically significant (p<0.01).3.Compared with Plin indexes of the total lung that were in-960～1024,-910～-960,-800～-910, three regions in normal group and all the case groups, the difference between them was statistically significant (p<0.01);but the difference of the all PIex indexes was statistically significant (p<0.01)4.There was statistical significance between the correlation with PI-960～-1024, PI-910～-1024 and FEV1%, FEV1/FVC (p<0.01), the PI-910～-1024 is Better.5.Excellent correlation was found between all the expiratory indexes with FEV1% and FEV1/FVC (p<0.01). There was statistical significance between the correlation with density difference,each indexes ratio, indexes variation percentage and FEV1%, FEV1/FVC (p<0.01),Conclusions1. The data and image quality obtained from 64 slices SCT chest scanning at low-dose in full inspiration and full expiration meets the requirements of pulmonary function assessment of patients with COPD and healthy people. It can replace the scanning of two phases at routine-dose to evaluate pulmonary function.2.64 slices SCT chest scanning at low-dose at full inspiration and full expiration can be used to evaluate pulmonary function of COPD and healthy people.Among all the indexes, Dex,Vex,PL-910, Dex-Din,the ration and the variation percentage were all the useful indexes to evaluate pulmonary function. (There was statistical significance between the correlation with all the indexes, FEV1%and FEVl/FVC.But PIex-910 and PIex-910/PIin-910were better.(The correlation coefficients were larger than 0.64)更多还原