血清细胞因子TGF-β1和IL-1β表达水平对急性放射性心脏损伤发生的影响

目的 研究胸部肿瘤放射治疗患者血清TGF-β1和IL-1β水平对急性放射性心脏损伤发生的影响。方法 接受常规适形或调强放疗的胸部肿瘤患者54例,PTV处方剂量为50~66 Gy,分析靶区剂量分布及危及器官受量。患者于放疗前及放疗结束后空腹采肘静脉血,应用酶联免疫吸附法检测血清中TGF-β1和IL-1β水平,并分别在放疗前后和放疗开始90 d内检测心肌酶、肌钙蛋白Ⅰ、心电图以及心功能指标评价患者心脏损伤状况,对急性放射性心脏损伤分级标准进行评价。分析血清TGF-β1和IL-1β水平对急性放射性心脏损伤的影响。结果 放疗前患者血清TGF-β1为(888.4±41.1)μg/L,放疗结束时为(926.1±23.1)μg/L,差异有统计学意义(t=-6.479, P<0.05);放疗后发生急性放射性心脏损伤患者血清TGF-β1为(900.6±34.5)μg/L,高于无急性放射性心脏损伤患者的(865.7±47.0) μg/L,差异有统计学意义(t=-2.646,P<0.05)。Spearman相关分析显示,TGF-β1放疗前基础水平、放疗前后差值与急性放射性心脏损伤相关(r=0.378、0.311,P<0.05)。患者放疗前与放疗结束时的血清IL-1β比较差异无统计学意义;放疗后发生急性放射性心脏损伤者与未发生急性放射性心脏损伤者血清IL-1β基础表达水平差异无统计学意义。患者放疗前IL-1β基础水平、放疗后表达水平、放疗前后差值与急性放射性心脏损伤无相关性。放疗前、后TGF-β1的表达水平与放疗后IL-1β的表达水平呈正相关(r=0.416、0.389,P<0.05)。结论 放疗后血清TGF-β1升高,放疗前基础表达水平及放疗前后差值与急性放射性心脏损伤相关。IL-1β与放射性心脏损伤无相关性。     

鼻咽癌调强放疗致急性放射性口干的剂量学研究

目的 探讨鼻咽癌调强放疗所致急性放射性口干与放疗剂量的关系。方法 收集2013年12月至2014年7月接受调强放疗的109例鼻咽癌患者,分析患者的一般临床资料及双侧腮腺、双侧下颌下腺、双侧涎腺(双侧腮腺+双侧下颌下腺)的照射剂量等数据。在放疗结束时根据口干程度把患者分为非重度口干组(57例)和重度口干组(52例),并对两组之间的一般资料以及相关的剂量学因素进行比较分析。记录双侧腮腺接受15~50 Gy照射剂量的体积百分比,采用Logistic多因素回归法分析急性重度口干的独立预测因子,并用受试者工作特征曲线(ROC)分析其诊断界值点。结果 至放疗结束,所有入组患者重度口干的发生率为47.7%(52/109)。临床因素的分析提示年龄、黏膜炎、化疗方式均与急性重度放射性口干的发生无关。非重度口干组和重度口干组剂量学指标比较的结果显示,两组平均剂量差异均有统计学意义(t=-6.179、-6.055、-2.293,P<0.05)。Logistic回归分析显示,V₃₄是判断急性重度放射性口干的独立预测因素。V₃₄的ROC曲线表明:V₃₄=49%对重度放射性口干预测的敏感度和特异度分别为71.2%和75.4% (OR=1.231,P<0.05,95%CI:1.116~1.357)。结论 在鼻咽癌调强放疗计划中,双侧腮腺的V₃₄是重度急性放射性口干的独立预测因子,可以作为评估发生急性重度放射性口干发生风险的剂量学指标。     

鼻咽癌同期放化疗中急性皮肤黏膜反应的临床观察及其相关因素分析

目的 探讨鼻咽癌患者同期放化疗中急性皮肤及黏膜反应的影响因素,对主要相关因素进行分析。方法 对85例接受同期放化疗的鼻咽癌患者进行研究,观察并记录BMI、每周放疗剂量、口腔黏膜及颈部皮肤反应情况、血常规等15项临床指标及实验室指标,并进行单因素分析和多因素分析,筛选决定性影响因素。结果 与急性放射性口腔黏膜反应发生密切相关的危险因素,有吸烟史（OR=3.467,P<0.05）和原发灶GTV单次量>2.15Gy（OR=3.393,P<0.05）;与急性放射性皮肤反应发生密切相关的危险因素,有糖尿病史（OR=87.859,P<0.05）,放疗前1周血红蛋白值>130g/L（OR=21.404,P<0.05）。结论 对于同期放化疗的鼻咽癌患者,吸烟史和原发灶GTV单次量为急性放射性口腔黏膜反应的独立影响因素,糖尿病史和放疗前1周的血红蛋白值为急性放射性皮肤反应的独立影响因素。     

食管癌根治切除术后辅助调强放疗胸腔胃照射剂量与急性放射性胸腔胃炎的关系

目的 研究食管癌术后调强放疗剂量学与胸腔胃放射性损伤的关系。方法 通过入组104例食管癌根治术后行调强放疗的患者,对其临床资料及放疗计划中胸腔胃剂量-体积参数与急性放射性胸腔胃炎的发生情况进行分析,ROC曲线分析与急性放射性胃炎发生可能相关的物理学指标,logistic法行单因素及多因素分析。结果 全组104例患者出现≥ 2级急性放射性胸腔胃炎者29例（27.88%）。与≥ 2级急性放射性胸腔胃炎相关的剂量-体积指标包括：胸腔胃D_max、D_mean、L₅~L₄₅、V₅~V₅₀。单因素分析显示,胸腔胃位置、胸腔胃D_max、D_mean、胸腔胃L₅~L₄₅和V₅~V₅₀均与≥ 2级急性放射性胸腔胃炎的发生显著相关（P<0.05）;多因素分析显示,胸腔胃位置、L₅、V₃₅与≥ 2级急性放射性胸腔胃炎的发生均显著相关（P<0.05）。ROC曲线所得L₅及V₃₅的最佳界值分别为14.00 cm和44.00%,胸腔胃L₅ ≥ 14.00 cm和L₅<14.00 cm发生≥ 2级急性放射性胸腔胃炎的概率分别为38.64%和20.00%（χ²=4.473,P<0.05）;V₃₅ ≥ 44.00%和V₃₅<44.00%发生≥ 2级急性放射胸腔胃炎的概率分别为57.58%和14.08%（χ²=7.263,P<0.05）。后纵隔胃患者≥ 2级急性放射性胸腔胃炎的发生率显著高于其他两组（χ²=12.881,P<0.05）。结论 胸腔胃剂量-体积参数对急性放射性胸腔胃炎的发生具有一定的预测价值,建议对术后需行放疗的食管癌患者慎重选择后纵隔胸腔胃手术方案。     

合并糖尿病或高血压的食管癌患者发生放射性食管炎和肺炎的危险因素分析

目的 探讨伴有糖尿病或高血压的食管癌患者接受放射治疗后急性放射性食管炎和肺炎发生情况。方法 回顾性分析373例食管癌患者接受三维适形或调强放射治疗资料,其中,伴有糖尿病者42例,无糖尿病者331例,伴高血压者99例,无高血压者274例。随访观察1年,分析有无糖尿病或高血压的患者放射性食管炎和肺炎的发生情况。结果 有无糖尿病患者1、2、3、4级放射性食管炎发生率分别为40.5%、38.1%、14.3%、4.8%和66.2%、27.8%、2.7%、1.8%。有无糖尿病患者1、2、3级放射性肺炎发生率分别为31.0%、16.7%、9.5%和30.8%、15.7%、1.2%。伴糖尿病的食管癌患者≥ 3级急性放射性食管炎和肺炎发生率均高于无糖尿病患者（χ²=13.573、12.279,P<0.05）。有无高血压患者1、2、3、4级放射性食管炎发生率分别为49.5%、38.4%、8.1%、3.0%和68.2%、25.5%、2.6%、1.8%。有无高血压患者1、2、3级放射性肺炎发生率分别为30.3%、18.2%、5.1%和31.0%、15.0%、1.1%。伴高血压的患者≥ 3级急性放射性食管炎和肺炎发生率均高于无高血压患者（χ²=5.695、5.422,P<0.05）。糖尿病是≥ 3级急性放射性食管炎和肺炎发生的独立因素。结论 糖尿病或高血压为根治性放疗食管癌患者发生严重（≥ 3级）急性放射性食管炎和肺炎的易感因素。     

宫颈癌外照射急性放射性直肠炎剂量-体积-时间关系研究

目的 回顾性分析宫颈癌调强放射治疗（intensity-modulated radiation therapy,IMRT）中急性放射性直肠炎的发生与直肠受照剂量、体积以及受照时间关系。方法 收集本院2011年1月至2013年12月行IMRT照射的51例宫颈癌病例,根据RTOG/EORTC毒性分级标准分为1~4级。用剂量体积直方图（DVH）评价标准计划下不同放射性直肠炎分级组的患者直肠受照剂量体积。分析直肠D_max、D_mean、D_{1 cm³}、D_{2 cm³}、D₄₀、V₄₀和出现症状时直肠受照剂量。结果 急性放射性直肠炎发生的平均时间为放疗后（23.06±12.01）d。与发生放射性直肠炎3~4级组相比,放射性直肠炎2级组的直肠D_max值更低,差异有统计学意义（F=5.268,P<0.05）;与发生放射性直肠炎3~4级组相比,放射性直肠炎1级、2级组的直肠D_{1 cm³}、D_{2 cm³}值均低于放射性直肠炎3~4级组（F=4.893、4.406,P<0.05）,而直肠D₄₀和V₄₀值的差异无统计学意义（P>0.05）。结论 宫颈癌患者IMRT放疗20 d左右较易发生急性放射性直肠炎,且较多发生轻度到中度急性放射性直肠炎,重度急性放射性直肠炎的发生率低。在宫颈癌IMRT放疗时,尽量减小直肠D_max、D_{1 cm³}、D_{2 cm³}的值,对降低重度急性放射性直肠炎的发生率有意义。     

深吸气屏气技术对左侧乳腺癌术后包含内乳淋巴结调强放疗的心脏剂量学影响

目的 探索左侧乳腺癌术后包含内乳淋巴结调强放疗时,实施深吸气屏气技术(DIBH)对心脏剂量 学的影响。方法 观察2021年10月至2022年7月蚌埠医学院第一附属医院23例左侧乳腺癌术后行包含内乳淋巴结调强放疗(IMRT)患者心脏和冠状动脉左前降支(LAD)在DIBH时相上剂量学参数的变化,并分析其实施效果的潜在影响因素。结果 与自由呼吸(FB)相比,DIBH状态下心脏体积缩小18% (t=10.47,P＜0.001)、左肺体积扩张42%(t=-14.55,P＜0.001),心脏及LAD的平均剂量D_mean、最大剂量D_max以及剂量体积参数V₅ ~ V₃₀均明显降低,差异具有统计学意义(t=-13.38 ~ -3.30,P＜0.05);相关性分析显示,左肺扩张的相对比值与心脏剂量减少的相对比值呈正相关(r=0.82,P＜0.001),患者年龄与心脏剂量减少的相对比值呈负相关(r=-0.56,P=0.005)。结论 本研究明确了左侧乳腺癌术后包含内乳淋巴结IMRT时实施DIBH,可有效地降低心脏及LAD的剂量,年龄和肺活量可能是DIBH实施效果的影响因素。     

左乳癌保乳术后混合调强放疗中利用多叶准直器遮挡技术减少心脏受照剂量的研究

目的 利用多叶准直器（MLC）遮挡技术减少左侧乳腺癌患者保乳术后混合调强放疗中心脏的受照剂量,降低放射性心脏损伤发生的风险。方法 选取18例左乳癌保乳术后患者,在自由呼吸状态下获取3DCT和4DCT图像。利用4DCT在3DCT图像上确定出靶区并分别制定混合调强治疗计划（H_IMRT）和为降低心脏受量而引入MLC遮挡技术的治疗计划（HSH_IMRT）,利用Compass系统对治疗计划进行剂量学验证。靶区处方剂量为50 Gy,分25次完成。比较两种治疗计划结果与剂量验证结果中靶区及危及器官的剂量学参数。结果 计划结果显示,与H_IMRT比较,HSH_IMRT靶区剂量均匀性更好,适形度差异无统计学意义（P>0.05）;全心脏D_mean较前者降低23.67%（t=13.693,P<0.05）,心脏其他亚结构的D_max和D_mean均较前者下降。剂量验证结果显示,两种计划靶区剂量均匀性与适形度差异无统计学意义（P>0.05）;HSH_IMRT与H_IMRT比较,全心脏的D_mean降低24.88%（t=13.782,P<0.05）;除左心室、右心室外,其他心脏亚结构的D_max以及所有心脏亚结构的D_mean均降低。患侧肺的V₂₀和D_mean在计划结果与验证结果中均显示HSH_IMRT更低。结论 在H_IMRT中合理引入MLC遮挡技术能够在保证其剂量学优势的前提下更多地减少心脏组织的受量,进一步降低心脏发生放射性损伤的风险。     

直肠癌新辅助同步加量调强放疗对侧方淋巴结转移的影响

目的 在侧方淋巴结转移的直肠癌中,评估侧方淋巴结加量放疗的疗效及安全性。方法 2016年1月至2022年12月入组103例合并侧方淋巴结转移的直肠癌患者,按随机数表法分为加量放疗组52例和常规放疗组51例。加量放疗组在盆腔放疗50 Gy的基础上,侧方淋巴结同步加量放疗至60 Gy。常规放疗仅盆腔放疗剂量50 Gy。研究首要终点为侧方复发率,比较两组的疗效及不良反应。结果 加量放疗组和常规放疗组新辅助放疗的不良反应及手术并发症相仿,侧方淋巴结治疗有效率分别为76.9%和56.9%(χ²=4.69,P=0.03),局部复发率分别为7.7%和25.5%(χ²= 5.92,P = 0.015),侧方复发率分别为3.8%和23.5%(χ²= 8.49,P = 0.004)。单因素分析显示,同步加量放疗、放疗后侧方淋巴结短径< 5 mm以及术后淋巴结病理阴性为侧方复发相关因素;多因素回归分析显示,加量放疗(HR=6.42, 95% CI: 1.40~29.49)及放疗后侧方淋巴结短径<5 mm(HR=0.17, 95%CI: 0.04~0.66)为侧方复发的独立相关因素。两组3年无病生存率(DFS)分别为73.25%和62.6%(P＞0.05),3年总生存率(OS)分别为87%和82.5%(P＞0.05)。结论 侧方淋巴结转移直肠癌同步加量放疗安全有效,加量放疗和新辅助治疗后侧方淋巴结短径<5 mm是侧方复发的独立影响因素。     

基于4D-CT高通气功能肺组织避让的胸部肿瘤放疗计划可行性研究

目的 建立基于4D-CT肺通气功能图像的胸部肿瘤高通气功能肺避让(HVFLA)的放疗计划设计流程,确定HVFLA的放疗计划策略,为胸部肿瘤患者开展HVFLA放疗临床试验提供支持。方法 基于前期已经建立的4D-CT肺通气功能图像深度学习模型,搭建计算平台将其融入放疗计划流程,进一步回顾性入组10例行4D-CT模拟定位的胸部肿瘤患者,根据建立的模型获取每位患者的4D-CT肺通气功能图像,根据肺通气量相对值高低自动将肺通气功能区域三等分为高、中和低通气功能肺,并导入Pinnacle³治疗计划系统。对于每位患者,根据靶区处方剂量和危及器官的剂量限值要求,采用容积旋转调强技术,分别设计临床计划和HVFLA计划,要求每个计划均满足临床要求,其中,HVFLA计划增加限制高功能肺的优化条件。通过比较靶区、危及器官(双肺、心脏和脊髓)和高功能肺的剂量学参数评价计划,剂量学参数包括靶区的D₂、D₉₈和平均剂量,双肺和高功能肺的V₅、V₁₀、V₂₀、V₃₀和平均剂量,心脏的V₃₀、V₄₀和平均剂量,脊髓的D_{1 cm³}等。采用配对t检验的方法对两组计划统计分析。结果 临床计划和HVFLA计划的靶区和危及器官均满足临床要求,HVFLA计划高功能肺的平均剂量、V₅、V₁₀、V₂₀ 和V₃₀平均分别减少1.2 Gy、5.9%、4.2%、2.6%和2.3%,均具有统计学意义(t=-8.07、4.02、-6.02、-7.06、-6.77,P<0.05)。双肺、心脏和脊髓的剂量学参数差异均无统计学意义(P>0.05)。结论 建立了基于4D-CT肺通气功能图像的高功能肺避让的放疗计划设计流程,HVFLA计划可以显著降低高功能肺的受照剂量,双肺、心脏和脊髓受照剂量无显著变化。HVFLA放疗计划策略可行,可以为胸部肿瘤患者开展HVFLA放疗提供支持。     

Features of carcinoid heart disease identified by cardiac computed tomography

BackgroundCarcinoid heart disease (HD) is a rare form of valvular heart disease, the features of which have not been fully described by cardiac computed tomography (CT).MethodsAll patients with carcinoid HD that underwent cardiac CT, either preoperatively or for assessment of coronary arteries, between Apr-2006 and Dec-2019 at the Royal Free Hospital, UK, were reviewed.ResultsOf 32 patients with carcinoid HD, 29 (91%) had heart valve involvement. Abnormalities of the tricuspid and pulmonary valves were present in all patients, affecting all three leaflets in 23/26 (89%) unoperated patients for both valves. The aortic valve was affected in 4/29 (14%) patients and the mitral valve in 5/29 (17%). Left heart valves were affected in 6/29 (21%) patients. One patient (1/29; 3%) had all four valves affected. Severe changes with significant valvular regurgitation were seen in ≥75% of patients with tricuspid, pulmonary, and aortic valve abnormalities. Three patients had carcinoid myocardial metastases (3/32; 9%) and one patient had constrictive pericarditis (1/32; 3%). Ten patients had surgery of whom four (40%) had invasive coronary angiography preoperatively. Ten patients had a patent foramen ovale. Cardiac CT allowed an accurate assessment of damage to different leaflets/cusps, particularly of the pulmonary valve, where visualization with echocardiography was often (3/8; 38%) incomplete.ConclusionCardiac CT is a powerful tool for assessment of cardiac valve abnormalities, coronary arteries and the spatial relationship of coronary arteries with myocardial metastasis in patients with carcinoid HD, and should form part of multimodal imaging of this complex pathology.     

中医药防治放射性皮肤损伤的研究进展

放射性皮肤损伤是指放射线对皮肤照射所引起的急慢性皮肤损伤。核灾难、放射性事故、放射性治疗、职业暴露等都有可能造成放射性皮肤损伤的发生。大约95%接受放射治疗的患者最终会在治疗过程中或治疗过程后发展为辐射诱发性皮炎,因此如何正确防治放射性皮肤损伤具有重要的现实意义。中医认为,放射性皮肤损伤属于火热毒邪,阻滞气血,损伤肌表,影响体内气血津液布散,损伤脏腑机能。本文综述放射性皮肤损伤中医理论的认识与发展,及中医内治法和外治法的研究进展,为中医药防治放射性皮肤损伤研究及治疗提供依据。     

急性期放射性脑损伤磁共振扩散张量成像的定量研究

目的 利用磁共振扩散张量成像(DTI)定量分析,探讨正常脑组织不同部位急性期放射损伤的敏感性。方法 44例欲行全颅放疗的颅内肿瘤患者,在放疗前及放疗后3周行磁共振常规扫描、增强扫描及扩散张量成像,测量非肿瘤侧大脑半球接受总放射剂量为27 Gy时的等剂量区域内脑回灰质、脑回白质、深部灰质、深部白质的表观扩散系数(ADC)、部分各向异性(FA)、相对各向异性(RA)、容积比率(VR)等指标,并进行对比分析。 结果 所有患者常规及增强磁共振扫描非肿瘤侧大脑半球均未发现异常信号,而放疗后脑回灰质ADC值升高(t=-3.819,P<0.05),脑深部灰质核团ADC、容积比率值升高(t=-3.31、-2.810,P<0.05),脑深部灰质核团FA、RA值降低(t=2.906、2.349,P<0.05),其余部位放疗前后DTI各指标差异无统计学意义。结论 在急性期脑灰质较白质对放疗损伤敏感,DTI能从组织细胞功能水平对放射性脑损伤急性反应进行评价。     

Mechanisms of radiation-induced skin injury and implications for future clinical trials

Abstract

Purpose: To summarize current knowledge regarding mechanisms of radiation-induced skin injury and medical countermeasures available to reduce its severity. Advances in radiation delivery using megavoltage and intensity modulated radiation therapy have permitted delivery of higher doses of radiation to well-defined tumor target tissues. Although skin is not a radiation dose-limiting tissue, injury to skin poses substantial morbidity risks in the curative treatment of cancers, especially when radiation is administered in combination with chemotherapy. In the continuum of radiation-induced skin injury, late effects are most severe being characterized by sub-cutaneous fibrosis and morbidity. The principal pathogenesis is initiated by depletion of acutely responding epithelial tissues and damage to vascular endothelial microvessels. Emerging concepts of radiation- induced skin injury suggest that the recovery of stromal stem cells and tissue repair remain chronically impaired by long-lived free radicals, reactive oxygen species, and pro-inflammatory cytokines/chemokines resulting in progressive damage after radiation exposure.

Conclusions: As pathways underlying the cellular and molecular mechanisms of radiation-induced skin injury are becoming better understood, novel approaches are being developed for mitigating or treating the associated pathogenesis.     

Heart rate variability in soccer players with mitral valve prolapse or benign arrhythmia

Abstract Numerous studies have reported increased cardiac vagal activity in well endurance-trained athletes. However, no clear data exist regarding the cardiac autonomic activity in athletes with common cardiovascular findings, such as mild mitral valve prolapse (MVP) and transient benign arrhythmias. Therefore, the purpose of this study was to investigate and compare the cardiac autonomic outflow by heart rate variability (HRV) analysis between soccer players with mild MVP and rhythm disorders and other athletes with transient benign arrhythmias but without any structural cardiac disease. Twenty Greek male soccer players with mild MVP (group A, aged 20.2±4.5 years), 20 players with benign cardiac rhythm and conduction disorders without structural cardiac disease (group B, aged 21.0±3.6 years) and 20 healthy age-matched sedentary men (group C) were examined. All subjects underwent clinical evaluation, resting electrocardiogram for QTc calculation, echocardiography and 24-h ambulatory Holter recordings for HRV analysis. The mean 24-h heart rate, the HRV index and the mean 24-h R-R interval were significantly increased in all athletes compared to controls (p<0.05). Moreover, group A presented significantly decreased HRV index compared to group B by 18.2% (p<0.05). Resting QTc was prolonged only in group B compared to groups A and C by 9.5% and 11.2%, respectively (p<0.05), whereas no significant difference was found between groups A and C. It is concluded that athletes with MVP present limited exercise-induced cardiac vagal predominance compared to those with benign arrhythmias and without any structural cardiac disease.     

The significance of calcific valvular heart disease in Tc-99m pyrophosphate myocardial infarction scanning: radiographic, scintigraphic, and pathological correlation.

Technetium-99m pyrophosphate (PPi) is currently considered the best scanning agent for the diagnosis of acute myocardial infarction. False-positive scans have been reported in association with unstable angina, alcoholic cardiomyopathy, and ventricular aneurysms. In this study, 86% of patients (12/14) with either calcific aortic or mitral valvular heart disease had positive PPi cardiac scintiscans and the location of the PPi uptake was limited to the calcific valve in all (9/9) of the patients who underwent valve replacement surgery. Six patients with valvular disease without radiologic evidence of calcium had negative PPi heart images. Three of these patients had surgical valve replacement, and in none was there increased uptake in the resected valve. Seventy-five percent of the patients with calcified aortic valves had localization of the PPi activity to the area of the aortic valve, whereas 50% of the patients with calcified mitral valves showed a diffuse pattern of uptake on the cardiac image. In vitro demonstration of increased radioactivity in surgically removed cardiac valves warrants the conclusion that Tc-99m PPi is taken up by calcified heart valves. We conclude that while PPi heart scanning is a sensitive indicator of acute myocardial infarction, false-positive scans can occur in the presence of calcific valvular disease, due to localization of PPi in the calcified portion of the valve.     

Dual-source CT cardiac imaging: initial experience

The relation of heart rate and image quality in the depiction of coronary arteries, heart valves and myocardium was assessed on a dual-source computed tomography system (DSCT). Coronary CT angiography was performed on a DSCT (Somatom Definition, Siemens) with high concentration contrast media (Iopromide, Ultravist 370, Schering) in 24 patients with heart rates between 44 and 92 beats per minute. Images were reconstructed over the whole cardiac cycle in 10% steps. Two readers independently assessed the image quality with regard to the diagnostic evaluation of right and left coronary artery, heart valves and left ventricular myocardium for the assessment of vessel wall changes, coronary stenoses, valve morphology and function and ventricular function on a three point grading scale. The image quality ratings at the optimal reconstruction interval were 1.24±0.42 for the right and 1.09±0.27 for the left coronary artery. A reconstruction of diagnostic systolic and diastolic images is possible for a wide range of heart rates, allowing also a functional evaluation of valves and myocardium. Dual-source CT offers very robust diagnostic image quality in a wide range of heart rates. The high temporal resolution now also makes a functional evaluation of the heart valves and myocardium possible.     

基于小动物精准放疗平台构建Wistar大鼠急性放射性食管炎动物模型

目的 基于小动物精准放疗平台(SARRP)建立Wistar大鼠急性放射性食管炎体内模型。方法 将36只Wistar大鼠按照随机数表法分为对照组、40、60和75 Gy组,每组9只。基于SARRP结合照射前磁共振图像(MRI)勾画大鼠食管靶区并制定计划,每次分别照射0、8、12和15 Gy,连续照射5 d,观察大鼠体重、进食量、食管病理和磁共振图像改变。结果 75 Gy组大鼠在照后第6天体重最先出现明显降低(P<0.05),照后第9天各照射组大鼠食管较对照组增粗(F=14.20,P<0.05)。照后第9天HE染色显示,40 Gy组放射性食管炎形成率为4/5,60 Gy 组食管炎形成率为5/5,且以轻度食管炎为主,75 Gy组食管炎形成率为5/5,其中3/5表现为重度。照后第9天各组大鼠病理损伤评分[M(Q₁, Q₃)]为0、1.0(0.5, 2.5)、1.0(1.0, 2.5)和4.0(1.5, 6.0),75 Gy组与对照组相比,差异有统计学意义(H=12.69,P<0.05)。动态监测颈部MRI图像后发现,照后第9天时各照射组大鼠食管信号增强变宽。结论 本实验基于小动物精准放疗平台结合MRI成功建立大鼠的急性放射性食管炎动物模型,75 Gy是最佳照射剂量,且第9天是最佳观察时间点。     

富氢水减轻造血干祖细胞的辐射损伤

目的 探讨富氢水对辐射诱导的造血干祖细胞（HSPCs）损伤的保护作用。方法 32只C57BL/6小鼠根据体重分层随机区组法分为健康对照组、富氢水组、照射组、照射+富氢水组,共4组,每组8只。富氢水组和照射+富氢水组小鼠于照射前5 min至照后7 d,每天灌胃给予0.5 ml富氢水,其余小鼠每天灌胃给予0.5 ml蒸馏水,照射组和照射+富氢水组小鼠接受2 Gy的¹³⁷Cs γ射线全身照射。照后15 d取小鼠骨髓,检测骨髓中HSPCs比例、骨髓细胞的克隆形成和移植重建能力、骨髓中LSK细胞的活性氧（ROS）水平和细胞凋亡情况。结果 与照射组相比,照射+富氢水组小鼠骨髓中造血祖细胞和LSK细胞比例升高（t=-4.935、-7.898,P<0.05）,骨髓细胞形成克隆的数目增加（t=5.488,P<0.05）,竞争性骨髓移植后受体小鼠的供体嵌合率升高（t=-12.769,P<0.05）,骨髓中LSK细胞的ROS水平和细胞凋亡比例降低（t=4.380、3.954,P<0.05）。结论 富氢水对2 Gy电离辐射诱导的HSPCs损伤具有一定的保护作用。