Absolute myocardial flow quantification with 82Rb PET/CT: comparison of different software packages and methods

Purpose

In clinical cardiac ⁸²Rb PET, globally impaired coronary flow reserve (CFR) is a relevant marker for predicting short-term cardiovascular events. However, there are limited data on the impact of different software and methods for estimation of myocardial blood flow (MBF) and CFR. Our objective was to compare quantitative results obtained from previously validated software tools.

Methods

We retrospectively analyzed cardiac ⁸²Rb PET/CT data from 25 subjects (group 1, 62?±?11 years) with low-to-intermediate probability of coronary artery disease (CAD) and 26 patients (group 2, 57?±?10 years; P?=?0.07) with known CAD. Resting and vasodilator-stress MBF and CFR were derived using three software applications: (1) Corridor4DM (4DM) based on factor analysis (FA) and kinetic modeling, (2) 4DM based on region-of-interest (ROI) and kinetic modeling, (3) MunichHeart (MH), which uses a simplified ROI-based retention model approach, and (4) FlowQuant (FQ) based on ROI and compartmental modeling with constant distribution volume.

Results

Resting and stress MBF values (in milliliters per minute per gram) derived using the different methods were significantly different: using 4DM-FA, 4DM-ROI, FQ, and MH resting MBF values were 1.47?±?0.59, 1.16?±?0.51, 0.91?±?0.39, and 0.90?±?0.44, respectively (P?<?0.001), and stress MBF values were 3.05?±?1.66, 2.26?±?1.01, 1.90?±?0.82, and 1.83?±?0.81, respectively (P?<?0.001). However, there were no statistically significant differences among the CFR values (2.15?±?1.08, 2.05?±?0.83, 2.23?±?0.89, and 2.21?±?0.90, respectively; P?=?0.17). Regional MBF and CFR according to vascular territories showed similar results. Linear correlation coefficient for global CFR varied between 0.71 (MH vs. 4DM-ROI) and 0.90 (FQ vs. 4DM-ROI). Using a cut-off value of 2.0 for abnormal CFR, the agreement among the software programs ranged between 76 % (MH vs. FQ) and 90 % (FQ vs. 4DM-ROI). Interobserver agreement was in general excellent with all software packages.

Conclusion

Quantitative assessment of resting and stress MBF with ⁸²Rb PET is dependent on the software and methods used, whereas CFR appears to be more comparable. Follow-up and treatment assessment should be done with the same software and method.     

Maximum principle for optimal control of anticipated forward–backward stochastic differential delayed systems with regime switching

This paper is concerned with a Pontryagin maximum principle for optimal control problem of stochastic system, which is described by an anticipated forward–backward stochastic differential delayed equation and modulated by a continuous‐time finite‐state Markov chain. We establish a necessary maximum principle and sufficient verification theorem for the optimal control by virtue of the duality method and convex analysis. To illustrate the theoretical results, we apply them to a recursive utility investment‐consumption problem, and the optimal consumption rate is derived explicitly. Copyright © 2015 John Wiley & Sons, Ltd.     

低剂量与常规剂量螺旋CT显示磨玻璃密度结节的对照研究

目的探讨低剂量及常规剂量螺旋CT扫描在检出磨玻璃密度肺结节(ground-glass nodule,GGN)的数目、边缘、内部结构与周边结构是否在统计学上存在显著差异。方法对经常规剂量(200mA)与层厚(5mm)螺旋CT扫描发现GGN患者56例同时行肺部低剂量(30mA)螺旋CT扫描,所得图像分别重建2mm、1mm,并按结节直径5mm,5~10mm,10mm不同大小分组,记录结节数目、边缘、内部特征以及周边结构等。结果低剂量与常规剂量螺旋CT扫描在检出GGN的数目、边缘、内部结构与周边结构无统计学意义。结论30mA低剂量螺旋CT扫描及层厚2mm可对GGN作出较好的判断,值得在早期肺癌筛查中应用。     

Krüppel 样转录因子 9 在胰腺癌中的表达及其临床意义

目的:探讨Krüppel样转录因子9(KLF9)在胰腺癌中的表达并探讨其与胰腺癌患者临床病理参数、预后的关系。方法:收集200例配对的胰腺癌组织与癌旁组织标本,分别用RT-PCR(28对)、Westernblot(4对)和免疫组化(全部标本)检测KLF9的表达,分析KLF9的表达水平与患者临床病理参数以及生存率的关系。结果:RT-PCR结果显示,在28例配对标本中,21例(75%)胰腺癌组织中KLF9m RNA的表达水平明显低于其癌旁正常胰腺组织。Westernblot结果显示,与癌旁正常胰腺组织比较,胰腺癌组织中KLF9蛋白表达水平明显下调。免疫组化显示,在胰腺癌组织中KLF9的染色强度明显减弱。与患者临床病理参数关系分析结果显示,KLF9的表达水平与肿瘤的分化程度(P=0.008)和血管侵犯(P=0.006)有关。生存分析显示,KLF9阳性表达患者1、2、3年总生存率明显高KLF9阴性表达患者(41%、31%、16%vs.18%、6%、6%)、中位生存时间明显长于KLF9阴性表达患者(21.05个月vs.11.82个月)(均P0.05)。结论:KLF9在胰腺癌中表达下调,且可能与不良预后密切相关。     

颈动脉外翻内膜剥脱术治疗颈动脉硬化狭窄

目的观察颈动脉外翻内膜剥脱术治疗颈动脉狭窄的疗效。方法24例颈动脉硬化狭窄患者,其中18例有慢性或一过性脑缺血症状,6例无症状;术前均行彩色超声、数字减影动脉造影(DSA)或CT和MRA扫描检查,颈动脉狭窄程度65％～95％;在颈丛麻醉下行颈动脉外翻内膜剥脱术,手术要点是于颈动脉分叉处斜形切断颈内动脉,外翻颈内动脉剥除有粥样斑块的内膜,同时从颈总动脉切口剥除颈总动脉和颈外动脉增厚的内膜。结果全组无手术死亡,术后随访3～20个月,临床症状均有不同程度改善,一过性脑缺血症状消失,4例仍有轻度慢性脑缺血症状。术后行脑部多普勒超声检查,22例脑部供血有明显改善。结论颈动脉外翻内膜剥脱术是一种安全、有效和合理的手术方式。     

The natural history of bladder carcinoma in situ after initial response to bacillus Calmette-Gúerin immunotherapy

ObjectivesTo explore patterns of recurrence, muscle invasion, and disease specific mortality in patients with bladder carcinoma in situ (CIS) who responded to an induction course with intravesical bacillus Calmette-Gúerin (BCG) immunotherapy.MethodsBetween June 1985 and December 2003, 104 patients (mean age 67 years) were diagnosed with either pure (38 patients) or concomitant (66 patients) CIS. Patients who responded to one (92 patients) or two (12 patients) induction courses of intravesical BCG instillation were included in the study. Response was determined and monitored by routine periodic bladder biopsies. Outcome of patients and the effect of various prognostic parameters were assessed after a median follow-up of 75 months.ResultsThe 5- and 10-year recurrence-free survival rates were 63% and 54%, respectively. The 5- and 10-year muscle-invasive-free survival rates were 79% and 77%, and the 5- and 10-year disease-specific survival rates were 90.5 and 85.8%, respectively. Median time to recurrence, muscle invasion, and disease-specific mortality was 18, 19, and 40 months, respectively. Pure and concomitant CIS were associated with a similar outcome. The recurrence of nonmuscle-invasive tumor did not increase the risk for muscle invasion or mortality.ConclusionsPure and concomitant bladder CIS share similar biologic behavior. Muscle-invasive disease is expected in about 25% of the BCG responders followed for long time periods and disease-specific mortality in 15%. Tumor recurrence, whether nonmuscle-invasive or muscle-invasive, follows a similar time table suggesting that these are not sequential but parallel and independent processes.     

癌胚抗原相关细胞黏附分子和人胸肾表达趋化因子在婴幼儿血管瘤组织中的表达

目的 检测癌胚抗原相关细胞黏附分子(CEACAM-1)和人胸肾表达趋化因子(CXCL-14)在不同时期婴幼儿血管瘤组织中的表达,并探讨其在血管瘤发生发展过程中的作用和意义.方法 应用免疫组化法和Western免疫印迹检测CEACAM-1和CXCL-14在增生期、消退期和消退完成期婴幼儿血管瘤组织中的表达,利用计算机图像分析技术测量平均吸光度.结果 CEACAM-1在增生期血管瘤组织中不表达或低表达,消退期呈强阳性表达,消退完成期呈阳性表达;各期之间CEACAM-1的表达差异有统计学意义(P<0.05);CXCL-14在增生早期血管瘤组织中不表达或低表达,消退期呈阳性表达,消退完成期呈强阳性表达,各期之间CXCL-14表达差异有统计学意义(P<0.05).结论 CEACAM-1和CXCL-14可能参与了婴幼儿血管瘤病理变化过程,在该病发生发展过程中起一定的作用.     

VSD在爆炸伤创面的临床应用研究

目的探讨封闭负压引流（vacuum sealing drainage,VSD）对软组织爆炸伤创面治疗的效果,为临床爆炸伤初级救治提供新的思路。方法对7例难治性创面彻底清创后表面用VSD泡沫敷料覆盖封闭引流,持续负压吸引,根据不同创面及时调整压力。结果经负压封闭引流7～10天后,5例I期移植皮片全部存活,2例彻底清创后VSD引流培养创面肉芽组织,II期植皮VSD再次覆盖引流均植皮成功,创面愈合。结论负压封闭引流技术早期用于爆炸创面,可抑制细菌增殖,促进肉芽组织形成和伤口愈合,能减少手术操作,减轻患者痛苦,是一种难治性创面的有效治疗方法。     

嗜肺军团菌mip/flaA二联优势抗原表位基因融合表达载体的构建及表达

目的 选取嗜肺军团菌mip/flaA优势抗原表位基因,构建mip/flaA二联优势抗原表位基因融合表达载体,并在原核系统中表达,为后续制备嗜肺军团菌蛋白疫苗提供初步的实验基础。方法 运用生物信息学方法对Mip和FlaA蛋白的二级结构和表面特性如理化性质、亲水性、可塑性、抗原指数以及胞外区等方面进行分析,选择其活性表位可能存在的区域为优势抗原表位区。通过PCR扩增和T4连接酶构建pET-mip、pET-flaA和pET-mip/flaA优势抗原表位基因融合表达载体,并诱导其在大肠杆菌中表达。结果 Mip和FlaA都存在多个潜在的抗原表位位点,选取其优势抗原表位区域进行克隆和表达获得成功,并成功表达了mip/flaA二联优势抗原表位融合蛋白。结论 DNA Star软件和Expasy在线蛋白分析系统能够成功预测嗜肺军团菌Mip和FlaA 抗原的表位;选取其优势抗原表位成功构建了pET-mip/flaA二联原核表达载体,并高效表达。     

腔内修复术治疗DeBakey Ⅲ型主动脉夹层动脉瘤中远期疗效评价

目的 探讨腔内修复术治疗DeBakey Ⅲ型主动脉夹层动脉瘤的中远期疗效.方法 2000年11月至2006年2月,行腔内修复术治疗DeBakey Ⅲ型主动脉夹层动脉瘤56例.所有患者随访21～84个月,平均(52±8)个月,术后1周及术后每年均行螺旋CT检查,分析其临床特点及治疗效果.结果 55例(98.2%)临床成功,2例(3.6%)术后出现一过性肾功能不全,术后30 d内1例(1.8%)死于多器官功能衰竭,,随访期间1例(1.8%)死于脑出血.结论 腔内修复术创伤小,痊愈快,并发症少,应视为DeBakeyⅢ型主动脉夹层动脉瘤的首选治疗方法.