双源CT灌注成像早期诊断放射性肺损伤的价值及其病理基础

发布时间：2018-07-05 16:12

本文选题：放射性肺损伤 + 断层扫描　；参考：《苏州大学》2014年博士论文

【摘要】：第一部分双源CT肺部灌注成像及其检测放射性肺损伤的临床意义目的：针对胸部放疗后的放射性损伤（radiation-induced lung injury, RILI）常规影像形态学改变出现较晚、临床难以早期诊断的问题，胸部功能成像能否比传统影像更早期反映RILI的功能变化？本研究探讨应用双源CT肺部灌注成像（CTperfusion imaging, CTPI）技术的可行性及其早期诊断RILI的临床价值。方法：选取临床筛查肺动脉栓塞而行4D-CT增强检查但影像诊断结果阴性以及临床最终排除了肺部疾患的患者20例作为对照组，年龄47-76岁（男、女各10例）。实验组为48例接受术后放疗的上段食管癌或胸腺肿瘤患者(照射总剂量均为60Gy)，年龄43-70岁（男27例，女21例）。放疗前及放疗1/2总剂量时间点(30Gy)行CTPI检查，同期检测外周血中肿瘤坏死因子(TNF-α)、转化生长因子(TGF-β1)，分析发生RILI(A组)与未发生RILI(B组)患者的血清细胞因子、常规CT表现及CTPI灌注值[相对血流量(rrBF)、相对血容量(rrBV)、相对毛细血管通透性(rrPS)]的变化，采用随机区组设计t检验比较两组间血清细胞因子、CTPI灌注值的差异，采用χ2检验比较常规CT与CTPI对RILI检出的差异。使用西门子新双源CT机（FLASH）肺部4D容积扫描技术作为CTP成像方法，先行常规高分辨率CT平扫（HRCT），后行灌注成像。结果：⑴对照组所有20例患者均能获得层次丰富、结构清晰的CTP图像，肺野内任意取不同大小的感兴趣区（ROI），均能获得重复性好的灌注值；正常成人肺的rBF、rBV及rPS平均值分别为149.3±18.3mL/100mL/min、14.86±2.65mL/100mL、9.54±2.91mL/100mL/min；肺部各灌注参数及密度值（HU）男女性别、左右部位差异均无统计学意义（P0.05）；上、下肺野ROI的rBF、rBV值有显著差异（P0.05），上中肺野、中下肺野之间的各参数值无明显差异（P0.05）。⑵48例患者中，18例发生RILl(A组)。A组外周血TNF-α和TGF-β1放疗前后的差异无统计学意义(均P0.05)。放疗1/2总剂量时，A、B两组的外周血TNF-α、TGF-β1组间差异无统计学意义(均P0.05)；但A组常规CT图像上有2例出现阳性征象。A组受照射肺组织rrBF、rrBV、rrPS均较照射前显著增高(均P0.05)；B组的rrBF、rrBV较照射前有增高，差异有统计学意义(均P0.05)，rrPS无明显变化(P0.05)；照射后A、B两组rrBF、rrBV、rrPS间差异均有统计学意义（均P0.05）。根据ROC曲线，设rrPs=1.22为阈值，诊断RILl的敏感度、特异度分别为88.9％、90.0％，优于HRCT的11.1％、90.0％(χ2=13.61,P0.05)。⑶对照组与实验组放射治疗前的各对应灌注值之间差异无统计学意义（P0.05）。结论：⑴双源CTPI技术能够用于肺组织的灌注成像研究，能定量分析肺组织血流动力学参数（rBF、rBV、rPS等）。⑵外周血中TNF-α、TGF-β1变化对早期检测肿瘤放疗患者RILI的价值尚不确定。⑶CTPI能反映放疗后肺组织血液动力学的变化，能早期反映RILI患者照射野的异常灌注，有可能成为早期检出RILI的有效工具。第二部分放射性肺损伤兔阶梯模型的制备方法及鉴定一、放射性肺损伤（RILI）兔阶梯模型的制备目的：针对人类放射性肺损伤（RILI）各期难以在临床上准确把握以及难以进行生化、影像、组织病理等重复性研究，故建立一种适合动态观测与研究的动物模型非常必要。本研究旨在探讨放射性肺损伤（RILI）兔阶梯模型的制备方法。方法：健康新西兰大白兔54只，随机分作A组、B组及C组，每组各18只。三组均由同一麻醉师使用同样的混合法麻醉技术，即先肌注地西泮（用量为0.8~1.0mL/kg），后肌注速眠新II号（用量为0.4~0.5mL/kg），然后经自制中型动物医学成像扫描床固定后作高能X线单侧全肺单次照射，照射剂量分别35Gy、25Gy及15Gy，分别于照射后第1、2、3、4、5、6、8、12、16、20、24周进行阶梯性常规CT观察。重点观察混合麻醉法的安全及有效性，以及比较各模型组出现CT阳性表现的时间及各组模型的总死亡率。结果：⑴三组模型麻醉效果显著，无意识的麻醉时间平均为30-40分钟，麻醉死亡率均为零。⑵A、B、C三组模型常规CT出现渗出性毛玻璃影的高峰时间点分别为2周、4周、16周，并均在随后的阶梯时间点得到进一步的证实，即RILI的产生；模型中途死亡数分别为4只、1只、1只，死亡率分别为22.2%、5.6%、5.6%。结论：混合法麻醉技术具有安全性高、重复性好、可控性强、易于操作等优点。B组（25Gy）具有成模时间适中、死亡率低、阶梯匀称等优势，利于进一步的RILI阶梯性分析，是首选的造模方法。二、放射性肺损伤阶梯模型的鉴定目的：临床上放射性肺损伤（RILI）的发生、发展的演变过程较为复杂，RILI的各期无明显分界，因此对RILI动物模型的动态观测及鉴定具有重要的临床指导意义。故本研究旨在探讨RILI兔阶梯模型的动态血清学及组织病理学鉴定，以确定阶梯模型的发生及演变过程。方法：麻醉方法同上，采用上述25Gy造模方法，共计60只健康新西兰大白兔经高能X线单侧全肺单次照射造模，设为实验组。同时随机同批次大白兔36只作假照射，设为为对照组，按下述照射后时间点分12个亚组，实验及对照组的每个亚组分别为5只、3只。分别于照射后第1、6、12、24、48、72小时及第1、2、4、8、16、24周进行开胸暴露心脏后穿刺提取4-8mL全血以备血清学检测，随后处死模型分别取两肺中带上、中、下野6处标本，分别进行HE染色光镜、电镜和局部肺组织TNF-a、TGF-β1的检测。实验组各时间点若有模型死亡，及时添加新个体进行补充。结果：⑴实验组两只分别于照射后第2、8周死亡，实验周期内总死亡率3.3%。⑵实验组所有兔受照射肺均产生了RILI，早期以急性炎症反应为主，晚期以进行性肺纤维化为特征。⑶实验组受照射1小时后局部肺组织TNF-α表达、48小时后TGF-β1表达与对照组差异有统计学意义（P值均＜0.05）。⑷光镜下，实验组受照射1小时后肺泡壁厚度、肺间质面积密度、24小时后间质内纤维母细胞和纤维细胞数量与对照组差异均有统计学意义（P值均＜0.05），并分别与照射后的时间直线相关（r=0.82086、0.87181、0.68230，P值均0.05）。⑸电镜下，实验组各时间点之间胶原纤维相对含量差异有统计学意义（F=100.31，P=0.000），对照组各时间点之间的差异无统计学意义（F=1.00，P=0.450）。实验组受照射48小时后肺内胶原纤维相对含量与对照组差异有统计学意义（P值均＜0.05），并与照射后时间直线相关（r=0.99318，P=0.0000）。结论：RILI兔阶梯模型具有良好的可靠性、稳定性以及RILI发生发展的阶梯性，较好地模拟了RILI的发生、发展的演变过程。细胞因子等对RILI的诊断有一定的参考意义，但不能作为诊断或预测的依据。第三部分放射性肺损伤兔阶梯模型功能成像技术研究目的：探讨健康新西兰大白兔的CT灌注成像（CTPI）技术参数及其定量分析的可行性。方法：健康新西兰大白兔36只假照射组（雌雄各18只），均由同一麻醉师使用同样的混合法麻醉技术，即先肌注地西泮（用量为0.8~1.0mL/kg），后肌注速眠新II号（用量为0.4~0.5mL/kg），然后经自制中型动物医学成像扫描床固定后，分别于假照射后照射后第1、6、12、24、48、72小时及第1、2、4、8、16、24周进行阶梯性常规CT扫描及CT灌注成像（CTPI）。CTPI使用设备为西门子新双源CT机（FLASH），采用全肺4D容积动态扫描技术。扫描参数：管电压100kv，管电流自动调节；4D1.5s模式；非离子对比剂规格为300mg I/mL，总量5mL，注射流速0.8mL/s。CTPI时采用专用动物呼吸机进行呼吸暂停15s。结果:36只大白兔均能获得层次丰富、结构清晰的CTPI图像，肺野内任意取不同大小的感兴趣区（ROI），均能获得重复性好的灌注值；正常兔肺的rBF、rBV及rPS平均值分别为123.8±25.9mL/100mL/min、13.04±2.07mL/100mL、8.97±2.14mL/100mL/min；肺部各灌注参数及密度值（HU）在雌雄性别、左右部位等方面的差异无明显统计学意义（P0.05）；上、下肺野ROI的rBF、rBV值的差异有显著统计学意义（P0.05）。假照射后不同时间点的各对应灌注值重复性佳，各时间点CTPI参数差异无明显统计学意义（P0.05）。结论:正常兔全肺CTPI各参数值能够进行定量测量与分析，且重复性好，，与人类全肺具有相似的变化规律。第四部分双源CT灌注成像早期诊断放射性肺损伤的实验研究目的：利用全肺双源CT灌注成像（CTPI）技术研究放射性肺损伤（RILI）兔阶梯模型的血流动力学变化规律，探索其发病进程中的病理基础及其早期诊断RILI的价值。方法：健康新西兰大白兔72只，利用随机数字表分为两组：实验组36只行25Gy单侧全肺单次照射，对照组36只为空白对照组，行单侧全肺假照射；两组按照射后1、6、12、24、48、72h和1、2、4、8、16、24周各分为12个亚组。每只兔于照射前和照射后所处亚组时间点做常规CT和CTPI，后取肺组织行光镜、电镜观察，将同期CTPI表现、病理变化及HRCT征象作对照分析。实验组与对照组CTPI参数比较采用t检验，CTPI参数与病理观察值的相关性采用两变量直线相关分析，CTPI与常规CT对RILI检出率比较采用卡方检验。结果：⑴对照组肺CTPI参数在各时间点上保持在相对稳定的水平。实验组照射后肺实质血流量（rBF）、血容量（rBV）和毛细血管通透性（rPS）在多数时间点上（6、12、72h及1、2、8、16、24周）与照射前差异有显著统计学意义（t=2.90～6.37，P＜0.05），呈“先降—后升—再降”的规律：1～12h先短暂的降低，后快速升高并显著高于对照组，于72h至2周分别达高峰，随后下降，并逐步低于对照组，至24周达最低值。⑵实验组受照射肺病理变化以毛细血管内皮细胞、基底膜和肺泡上皮细胞损伤为主，并随时间呈现一定规律性。实验组照射后肺rBF、rBV与病理改变有显著相关性（r=0.74、0.83，均有P＜0.05），rPS与毛细血管外红细胞数、毛细血管基底膜破坏之间有显著依存关系（r=0.87、0.88，均有P＜0.05）。⑶在所有时间点上，CTPI对RILI的检出率均高于HRCT，两者差异有统计学意义（χ2=4.37，P=0.036）。根据ROC曲线，两者诊断RILI的敏感度、特异度分别达92.3%、90.0%与69.2%、90.0%（Z＝13.06，P0.05），CTPI的诊断效能明显优于常规CT，尤其是在RILI模型的早期阶段（放疗后的前4周）。结论：CTPI参数初步揭示了RILI过程中的血流动力学演变规律，并间接反映以肺毛细血管通透性为主要变化的病理生理状态；RILI的CTPI异常在时间上先于常规CT，有望成为早期检测与早期诊断RILI的有力手段。
[Abstract]:Part I: dual source CT lung perfusion imaging and its clinical significance in radiation-induced lung injury
Objective: in the case of radiation-induced lung injury (RILI) after chest radiotherapy, the conventional image morphologic changes are late, and the clinical difficulty is difficult to diagnose early. Can the chest functional imaging reflect the function changes of RILI more early than the traditional image? This study applies the dual source CT pulmonary perfusion imaging (CTperfusion imagin). The feasibility of G, CTPI and its clinical value in early diagnosis of RILI.
Methods: 20 patients, aged 47-76 years (male and female, 10 cases), were selected from the clinical screening of pulmonary embolism with 4D-CT enhanced examination but negative imaging diagnosis and the final clinical exclusion of lung disease. The experimental group was 48 cases of upper esophageal or thymic tumor (total radiation dose of 60Gy). 43-70 years of age (27 males and 21 females). CTPI examination before and after radiotherapy (30Gy), and simultaneous detection of tumor necrosis factor (TNF- alpha) and transforming growth factor (TGF- beta 1) in peripheral blood, serum cytokine, routine CT expression and CTPI perfusion value [relative blood flow (rrBF)) of RILI (group A) and RILI (B group) patients. For the change of blood volume (rrBV) and relative capillary permeability (rrPS), the difference of serum cytokine and CTPI perfusion value between two groups was compared by random area group design t test. The difference between the routine CT and CTPI was compared with the routine CT and CTPI. The lung 4D volume scan technique of the new SIEMENS dual source CT machine (FLASH) was used as the CTP imaging method first. Conventional high-resolution CT plain scan (HRCT) was performed and perfusion imaging was performed later.
Results: (1) all the 20 patients in the control group were able to obtain a rich, clear structure CTP image, ROI in the lung field, and can obtain a good repetitive perfusion value. The average value of rBF, rBV and rPS in normal adult lung was 149.3 + 18.3mL/ 100mL/min, 14.86 + 2.65mL/100mL, 9.54 + 2.91mL/100mL/min, lung, lung, and lung. There was no significant difference between the sex and sex of the Department of perfusion and density (HU), and the difference of the left and right parts of the two sexes (P0.05); the rBF of ROI in the lower lung field, rBV value had significant difference (P0.05), there was no significant difference between the upper and middle and lung fields and the middle and lower lung fields (P0.05). (2) 48 patients had RILl (A group).A group peripheral blood TNF- alpha and TGF- beta 1 before and after radiotherapy. There was no statistical significance (all P0.05). There was no significant difference between groups of peripheral blood TNF- A and TGF- beta 1 in group A and B two with total 1/2 dose (P0.05), but there were 2 positive signs in the conventional CT image of A group and rrBF in the lung tissue of the lung tissue in the.A group. The difference was statistically significant (all P0.05), and there was no significant change in rrPS (P0.05). After A, B two groups rrBF, rrBV, rrPS were statistically significant (P0.05). According to the ROC curve, rrPs=1.22 as the threshold, the sensitivity of the RILl was diagnosed, the specificity was 88.9%, 90%, respectively, 11.1%, 90% (chi square). (x, 90%) and (3) control group and (3) control group and (3) control group and There was no significant difference in the corresponding perfusion values between the experimental group before and after radiotherapy (P0.05).
Conclusion: (1) the dual source CTPI technique can be used to study the perfusion imaging of lung tissue and can quantitatively analyze the hemodynamic parameters of lung tissue (rBF, rBV, rPS, etc.). (2) the change of TNF- alpha and TGF- beta 1 in peripheral blood is uncertain for the early detection of RILI in patients with tumor radiotherapy. (3) CTPI can reflect the changes in hemodynamics of lung tissue after radiotherapy and can be reversed in early stage. Abnormal perfusion of radiation field in patients with RILI may be an effective tool for early detection of RILI.
The second part is the preparation and identification of rabbit ladder model for radiation lung injury.
Preparation of a rabbit ladder model for radiation lung injury (RILI)
Objective: it is necessary to establish an animal model suitable for dynamic observation and study of human radionuclide injury (RILI), which is difficult to accurately grasp in clinical and difficult to carry out biochemical, imaging, histopathological and other repetitive studies. The purpose of this study is to explore the preparation method of the rabbit ladder model of radionuclide injury (RILI).
Methods: 54 healthy New Zealand white rabbits were randomly divided into group A, group B and group C, 18 in each group. The same anesthetic technique was used by the same anesthesiologist in the three groups, that is, the first anaesthediazepam (0.8~1.0mL/kg) was injected first, and then the new II number (0.4~0.5mL/kg) was injected after the muscle injection (the dosage was 0.4~0.5mL/kg), and then fixed by the self-made medium size animal medical imaging scanning bed. High energy X-ray single side whole lung irradiation, irradiation dose of 35Gy, 25Gy and 15Gy respectively, were observed on the ladder routine CT after 1,2,3,4,5,6,8,12,16,20,24 week respectively. The safety and effectiveness of mixed anesthesia were observed, and the time of CT positive expression in each model group and the total mortality of each model were compared.
Results: (1) the anesthetic effect of the three groups was significant, the time of unconscious anesthesia was 30-40 minutes, and the death rate of anesthesia was zero. 2. A, B, C three models, the peak time points of the exudative glass shadow of the three groups were 2 weeks, 4 weeks, 16 weeks respectively, and all were further confirmed at the subsequent step time point, that is, the production of RILI; in the model The number of deaths was 4, 1 and 1, respectively, with a mortality rate of 22.2%, 5.6%, 5.6%.
Conclusion: the mixed method of anaesthesia has the advantages of high safety, good reproducibility, strong controllability and easy operation. The.B group (25Gy) has the advantages of moderate mold forming time, low mortality and staircase symmetry, which is beneficial to further RILI ladder analysis. It is the first choice method.
Two, identification of the ladder model of radionuclide injury
Objective: the development of radiation-induced lung injury (RILI) is more complicated, and there is no clear demarcation in each period of RILI. Therefore, it is of important clinical significance for the dynamic observation and identification of RILI animal model. Therefore, this study aims to explore the dynamic serology and histopathological identification of the RILI rabbit staircase model in order to determine the ladder. The occurrence and evolution of the model.
Methods: in the same way, 60 healthy New Zealand white rabbits were created by high energy X-ray single lung single irradiation, and the experimental group was set up as the experimental group. At the same time, 36 rabbits were randomly irradiated with the same batch of white rabbits, set up as the control group, and divided into 12 subgroups according to the time point of the following irradiation, and each subcomponent of the experiment and the control group was divided into 12 subgroups. 5, 3, respectively, after exposure to the heart after exposure to the chest 1,6,12,24,48,72 hours and 1,2,4,8,16,24 weeks after exposure to the heart to extract 4-8mL whole blood for serological examination. Then the model was executed in two lungs, middle and lower field 6 specimens, respectively, HE staining light microscopy, electron microscopy and local lung tissue TNF-a, TGF- beta 1 detection. If there are model deaths at each time point, new individuals will be added in time.
Results: (1) the experimental group died after 2,8 week after irradiation, and the total mortality was 3.3%. in the experimental period. (2) all the rabbits in the experimental group were exposed to RILI, early acute inflammatory reaction and progressive pulmonary fibrosis in the early stage. (3) the expression of TNF- alpha in the local lung tissue in the experimental group after 1 hours of irradiation, and the TGF- beta 1 after 48 hours. The difference between the control group and the control group was statistically significant (P value < 0.05). 4. Under the light microscope, the thickness of the alveolar wall and the density of the interstitial area of the lung in the experimental group were 1 hours after irradiation, and the number of fibroblast and fibroblast in the interstitial tissue after 24 hours was statistically significant (P < 0.05), and was linearly related to the time after irradiation (r=0.82086 0.87181,0.68230, P values were all 0.05). Under the electron microscope, the relative content of collagen fiber in the experimental group was statistically significant (F=100.31, P=0.000), and there was no statistical difference between the control group (F=1.00, P=0.450). The relative content of collagen fiber in the experimental group was statistically different from that of the control group after 48 hours of irradiation. Significance (P < 0.05), and correlated linearly with the time after irradiation (r=0.99318, P=0.0000).
Conclusion: the RILI rabbit staircase model has good reliability, stability and the staircase of RILI development. It can simulate the occurrence of RILI and the evolution process. The cytokine has some reference significance for the diagnosis of RILI, but it can not be used as a basis for diagnosis or prediction.
The third part is the functional imaging technology of rabbit model with radiation lung injury.
Objective: To explore the feasibility of quantitative analysis of CT perfusion imaging (CTPI) parameters in healthy New Zealand rabbits.
Methods: 36 healthy New Zealand white rabbits (18 males and males each) were used by the same anesthesiologist, the same anaesthetized technique was used by the same anesthesiologist, that is, first intramuscular injection of diazepam (the amount of 0.8~1.0mL/kg), and then the post muscle anaesthetized new II (0.4~0.5mL/kg). After 1,6,12,24,48,72 hours and 1,2,4,8,16,24 weeks, the ladder routine CT scan and CT perfusion imaging (CTPI).CTPI use equipment are SIEMENS's new dual source CT (FLASH), and the whole lung 4D volume dynamic scanning technique is used. The scanning parameters: the tube voltage 100kV, the tube current auto tuning, 4D1.5s mode, and the non ion contrast agent specification for 300mg I/m L, the total amount of 5mL, the injection rate of 0.8mL/s.CTPI when using a special animal ventilator for apnea 15s.
Results: all the 36 rabbits were able to obtain a rich and clear CTPI image with a distinct size of ROI in the lung field. The average value of rBF, rBV and rPS in normal rabbit lung was 123.8 + 25.9mL/100mL/min, 13.04 + 2.07mL/100mL, 8.97 + 2.14mL/100mL/min, and pulmonary perfusion parameters. And the density value (HU) had no significant statistical significance (P0.05) in gender, left and right position (P0.05), and the difference of rBV value of ROI in the lower lung field was statistically significant (P0.05). The corresponding perfusion values at different time points after sham irradiation were good, and there was no significant statistical significance (P0.05) for the difference of CTPI parameters at each time point.
Conclusion: the parameters of the whole lung CTPI can be quantitatively measured and analyzed, and the repeatability is good, which is similar to that of the whole lung.
The fourth part is an experimental study of early diagnosis of radiation-induced lung injury by dual source CT perfusion imaging.
Objective: To study the hemodynamic changes in the rabbit model of radionuclide injury (RILI) by using the whole lung dual source CT perfusion imaging (CTPI) technique, and to explore the pathological basis and the value of early diagnosis of RILI in the course of the disease.
Methods: 72 healthy New Zealand white rabbits were divided into two groups by random numbers: 36 rats in the experimental group were irradiated with 25Gy unilateral whole lung, and 36 in the control group were blank control group, and the two groups were divided into 12 subgroups according to 1,6,12,24,48,72h and 1,2,4,8,16,24 weeks after radiation. CT and CTPI were performed at the time point of the group, then the lung tissue was taken by light microscopy and electron microscopy, and the CTPI expression, pathological changes and HRCT signs were compared. The experimental group and the control group were compared with the CTPI parameters by t test. The correlation between the CTPI parameters and the pathological observation values was analyzed by the two variable linear phase correlation analysis. CTPI and conventional CT were used to compare the detection rate of RILI. Chi square test.
Results: (1) the pulmonary CTPI parameters in the control group remained relatively stable at all time points. The pulmonary parenchyma blood flow (rBF), blood volume (rBV) and capillary permeability (rPS) in the experimental group were statistically significant (t=2.90 to 6.37, P < 0.05) at most time points (t=2.90 to 6.37, P < 0.05), showing a "first drop". The law of post rise and second descent: 1 ~ 12h was reduced first briefly, then increased rapidly and was significantly higher than that of the control group, reaching the peak in the 72h to 2 weeks, and then decreasing, and gradually decreasing to the control group, and reaching the lowest value at 24 weeks. 2. The experimental group was subject to the pathological changes of the capillary endothelium, basal membrane and alveolar epithelial cells in the experimental group. The time showed a certain regularity. There was a significant correlation between the rBF and rBV of the lung in the experimental group and the pathological changes (r=0.74,0.83, P < 0.05). There was a significant difference between the number of rPS and the extra capillary red blood cells and the destruction of the capillary basement membrane.
【学位授予单位】：苏州大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：R730.44

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