基于冠状动脉CTA的血流储备分数评估心肌缺血Meta分析

目的 探讨基于冠状动脉CTA的血流储备分数(FFR_CT)评估心肌缺血的准确性。方法 检索2004年1月—2015年2月Pubmed、Cochrane图书馆、Embase、中国期刊全文数据库(CNKI)、中国生物医学文献数据库(CBM)、万方数据知识资源系统关于FFR_CT在评估心肌缺血准确性方面的文献,对符合纳入条件的文献行进一步质量评估以及异质性检验。汇总敏感度和特异度,通过汇总工作特征曲线(SROC)和曲线下面积(AUC)评价采用FFR_CT诊断心肌缺血的临床价值。结果 共纳入4篇文献,质量分级均为A级。纳入研究的总患者数为662例,血管1117条。FFR_CT在患者及血管水平汇总后的敏感度分别为0.90(95%CI 0.85~0.93)和0.83(95%CI 0.78~0.87);特异度分别为0.72(95%CI 0.67~0.76)和0.78(95%CI 0.75~0.81);诊断比值比(DOR)分别为24.34(95%CI 10.84~54.65)和21.09(95%CI 7.51~59.24),AUC分别为0.9415、0.9140。结论 FFR_CT能有效提高冠状动脉CTA对心肌缺血的诊断准确性。     

局灶性机化性肺炎及周围型肺癌能谱CT表现

目的 观察局灶性机化性肺炎（FOP）和周围型肺癌（PLC）的能谱CT表现。方法 回顾性分析40例经病理证实的FOP（FOP组）和60例PLC患者（PLC组），均接受胸部双期能谱CT检查。测量并记录病灶动脉期及静脉期单能量图像CT_{40~100 keV}值（HU）、碘（水）值、水（碘）值及有效原子序数，绘制相应能谱曲线，计算能谱曲线斜率（λ_HU）；比较2组各定量参数的差异。结果 2组患者年龄、性别、临床症状、病灶大小及位置差异均无统计学意义（P均>0.05）。PLC组动脉期CT_{40 keV}、CT_{50 keV}、CT_{60 keV}及CT _{70 keV}值、λ_{70 keV}、碘（水）值、有效原子序数均高于FOP组（t=3.46、3.08、3.08、2.03、2.32、2.69、2.73，P均<0.05）；静脉期CT_{40 keV}、CT_{50 keV}、CT_{60 keV}及CT _{70 keV}值、λ_{70 keV}、碘（水）值、有效原子序数均低于FOP组（t=-3.51、-3.82、-3.01、-2.30、-2.76、-2.40、-2.43，P均<0.05）；其余动脉期及静脉期能谱参数值组间差异均无统计学意义（P均>0.05）。结论 FOP与PLC能谱CT表现存在一定差异，可为鉴别诊断提供参考。     

CT血流储备分数对心肌缺血病变的诊断效能研究

目的 以导管测量血流储备分数（FFR）为金标准，评价基于血流动力学优化融合模型的CT血流储备分数（CT-FFR）对冠状动脉狭窄所致心肌缺血病变的诊断效能。方法 前瞻性选择127例接受冠状动脉CT血管成像（CCTA）、1周内冠状动脉造影及经导管FFR测量患者（152支血管），以CCTA观察病变狭窄程度，计算CT-FFR。以FFR<0.8为判断心肌缺血金标准，绘制CT-FFR及CCTA的ROC曲线，获得AUC。计算两种方法诊断心肌缺血的敏感度、特异度、阳性预测值、阴性预测值及准确率。结果 CT-FFR与导管测量FFR一致性良好，仅6.6%测量值在95%一致性界限之外。CT-FFR诊断心肌缺血AUC在患者水平（0.92 vs 0.69，P<0.001）和血管水平（0.93 vs 0.69，P<0.001）均优于CCTA。以患者水平CT-FFR<0.8诊断心肌缺血的敏感度、特异度和准确率分别为84.1%、90.6%和85.8%，CCTA>50%分别为82.5%、54.7%和68.5%；血管水平CT-FFR<0.8分别为88.0%、84.7%和84.9%，CCTA>50%分别为80.6%、57.7%和69.1%。CT-FFR对于血管水平狭窄程度30%~70%病变诊断效能仍佳。结论 CT-FFR对心肌缺血病变的诊断效能优于CCTA，有助于临床筛查心肌缺血病变。     

经胸冠状动脉超声血流动力学参数评价冠状动脉狭窄程度

目的 探讨经胸冠状动脉超声(TTE)血流动力学参数评估冠状动脉狭窄程度的价值。方法 回顾性分析56例可疑冠心病患者的影像资料。测量冠状动脉正常组(无狭窄)、轻度狭窄组(狭窄率<50%)、中度狭窄组(狭窄率50%~69%)及重度狭窄组(狭窄率70%~99%)狭窄处TTE舒张期峰值流速(PDV),其远端最慢处流速(PDV_DIS)及流速比值(PDV/PDV_DIS)。并进行统计学分析。结果 TTE显示良好彩色血流的血管分支共113支;以CAG为金标准,其中冠状动脉正常组18支,轻度狭窄组19支,中度狭窄组30支,重度狭窄组46支。轻度狭窄组PDV、PDV/PDV_DIS与冠状动脉正常组差异均无统计学意义(P均>0.05)。中度狭窄组PDV、PDV/PDV_DIS高于冠状动脉正常组(t=5.13、7.11)和轻度狭窄组(t=4.45、6.59),重度狭窄组PDV、PDV/PDV_DIS高于冠状动脉正常组(t=10.63、11.43)、轻度狭窄组(t=10.06、11.04)和中度狭窄组(t=7.07、5.17),差异均有统计学意义(P均<0.05)。PDV、PDV/PDV_DIS与狭窄率呈正相关(r=0.82、0.87,P<0.01)。诊断冠状动脉中、重度狭窄时,PDV阈值分别为40.48、58.52 cm/s,敏感度分别为86.67%、86.96%,特异度分别为86.49%、92.54%;PDV/PDV_DIS阈值分别为1.44、1.98,敏感度分别为90.00%、82.61%,特异度分别为97.30%、89.55%。结论 冠状动脉狭窄率与TTE血流动力学参数有关,PDV及PDV/PDV_DIS可用以评价冠状动脉狭窄程度。     

可切除胰腺导管腺癌CT强化程度与病理的相关性

目的 分析胰腺导管癌（PDAC）增强CT强化程度与病理的关系，观察其对评估PDAC患者预后的价值。方法 回顾性分析150例经术后病理证实的PDAC患者，术前均接受胰腺CT平扫及双期（实质期和门静脉期）增强扫描，测量增强CT双期肿瘤与周围胰腺实质的CT值差（实质期和门静脉期CT_{胰腺-肿瘤}）及肿瘤强化后与平扫期CT值差（CT_{实质期-平扫期}和CT_{门静脉期-平扫期}），观察其与肿瘤分化程度及其内纤维间质含量的关系，分析PDAC患者生存时间的独立影响因素。结果 实质期CT_{胰腺-肿瘤}与肿瘤分化程度呈中度负相关（P<0.05），余各CT值差与分化呈低度相关（P均<0.05）；实质期CT_{胰腺-肿瘤}与肿瘤内纤维间质含量呈负相关（r=-0.51，P<0.05）。肿瘤分化程度、淋巴结转移、手术切缘状态为PDAC患者生存时间的独立危险因素（P均<0.05）。结论 PDAC实质期CT_{胰腺-肿瘤}与其病理级别及其内纤维间质含量均呈负相关；值差越小，病理级别越低，患者存活时间越长。     

经皮纳米刀消融猪肾脏后肾血流灌注的变化

目的 探讨经皮纳米刀消融实验用小型猪肾脏后肾血流灌注的变化。方法 实验用巴马小型猪6头,随机选取每头猪一侧肾脏作为实验组,另一侧作为正常对照组。实验组采用CT导向经皮穿刺技术将纳米刀消融探针置入肾实质内预定治疗区域,正常对照组不采取任何治疗措施。采用CT灌注成像技术,对实验组行不可逆电穿孔消融后,分别于消融术后即刻、2、4、8、16周行双侧肾脏CT灌注成像,分析计算各个时间点肾血流灌注参数,包括肾实质血流量（BF）、血容量（BV）、最大增强值（PE）、达峰时间（TTP）。对不同时间点两侧肾脏实质灌注参数差异进行统计学分析。结果 对6头实验猪均穿刺并消融成功,且在各时间点均成功完成CT灌注成像。消融后即刻实验组BV、BF、PE值均低于正常对照组（P均<0.05）,TTP值则高于正常对照组（P<0.05）;消融后2、4、8、16周两组各参数差异均无统计学意义（P均>0.05）。结论 经皮纳米刀肾脏消融术后,急性期可降低消融区肾脏血流灌注,消融后2周消融区血流灌注即可恢复。纳米刀消融肾脏对肾血流灌注的影响暂时且可逆。     

对比PETRA-MRA、TOF-MRA及CTA评估颅脑前循环动脉狭窄

目的 对比径向采集逐点编码缩短时间MR血管成像（PETRA-MRA）、时间飞跃法MRA （TOF-MRA）及CT血管成像（CTA）评估颅脑前循环动脉狭窄程度及长度的效能。方法 回顾性分析56例经颅脑数字减影血管造影（DSA）确诊颅脑前循环动脉狭窄患者的颅脑PETRA-MRA、TOF-MRA和CTA资料,采用组内相关系数（ICC）及Bland-Altman法观察PETRA-MRA与TOF-MRA、CTA评估颅脑前循环动脉狭窄程度及长度与DSA结果的一致性,以及分析上述评估结果与DSA的相关性。结果 Bland-Altman分析显示,以DSA为标准,PETRA-MRA评估颅脑前循环动脉狭窄程度的变异系数、偏差及一致性限度范围分别为13.30%、1.04及（－13.37,15.46）,TOF-MRA分别为15.89%、2.81及（－14.68,20.29）,CTA分别为20.17%、11.19及（－12.66,35.04）。PETRA-MRA、TOF-MRA及CTA评估颅脑前循环动脉狭窄程度（ICC=0.92、0.89、0.80）,以及PETRA-MRA、TOF-MRA评估颅脑前循环动脉狭窄长度与DSA结果的一致性均好（ICC=0.99、0.97）,而CTA评估颅脑前循环动脉狭窄长度与DSA结果的一致性差（ICC=0.30）。PETRA-MRA、TOF-MRA及CTA评估颅脑前循环动脉狭窄程度（r_s=0.94、0.86、0.80）及其长度（r_s=0.98、0.97、0.70）均与DSA结果呈正相关（P均<0.01）。结论 PETRA-MRA评估颅脑前循环动脉狭窄的效能优于TOF-MRA及CTA。     

十二指肠球部溃疡CT表现

目的 观察十二指肠球部溃疡的CT表现。方法 回顾性分析经胃镜确诊的44例十二指肠球部溃疡（溃疡组）和51例无十二指肠球部溃疡患者（对照组）的上腹部平扫及增强CT，比较组间十二指肠球部肠壁厚度、肠壁强化程度[动脉期及门静脉期CT值与平扫CT值的差值（ΔCT_动脉期和ΔCT_门静脉期）]、强化方式、黏膜面CT表现及周围脂肪间隙改变，绘制差异有统计学意义的参数诊断溃疡的ROC曲线，计算其AUC，评价其诊断效能；计算溃疡组CT漏诊率。结果 溃疡组十二指肠球部肠壁厚度[（7.52±2.30）mm]大于对照组[（2.89±0.75）mm，t=12.76，P<0.01]，2组肠壁ΔCT_动脉期及ΔCT_门静脉期差异均无统计学意义（t=-0.27、0.80，P均>0.05）。溃疡组十二指肠球部肠壁分层样强化、黏膜面不规则及周围脂肪间隙模糊发生率高于对照组（χ²=56.12、65.94、45.71，P均<0.01）。根据十二指肠球部肠壁厚度、强化方式、粘膜面CT表现及周围脂肪间隙改变诊断溃疡的AUC分别为0.99、0.90、0.93及0.84。溃疡组CT漏诊36例，漏诊率81.82%（36/44）。结论 肠壁增厚、分层样强化、黏膜面不规则伴周围脂肪间隙模糊为十二指肠球部溃疡的典型CT表现，准确识别有利于降低漏诊率。     

床旁彩色及脉冲多普勒(双功能)超声评估原位肝移植术后并发症

目的 观察床旁彩色及脉冲多普勒(双功能)超声评估原位肝移植(OLT)术后并发症的价值。方法 回顾性分析65例接受OLT患者术后第1、3、7天床旁腹部双功能超声检查资料,评估肝脏实质回声及肝固有动脉及门静脉等血流束,测量门静脉峰值流速(PVPV)、肝动脉主干收缩期血流峰值流速(PSV)及血流阻力指数(RI)。根据腹部CT增强、CT血管成 像(CTA)、超声造影(CEUS)、临床干预(包括增强免疫抑制剂和二次移植手术)或病理结果,绘制受试者工作特征(ROC)曲线,计算曲线下面积(AUC),评估以OLT后第7天内超声所测PSV(PSV_第7天)及RI(RI_第7天)判断有无并发症的效能。结果 65例OLT后第1、3及7天,PVPV分别为71.00(45.50,96.50)、57.50(42.00,71.00)及50.00(33.00,66.00)cm/s,RI分别为0.68±0.16、0.69±0.17、0.66±0.13,各时间点间PVPV及RI差异均无统计学意义(H=5.475、P=0.065,F=0.964、P=0.501);PSV分别为63.00(44.50,89.00)、47.00(31.50,64.50)及50.00(38.25,64.75)cm/s,各时间点差异有统计学意义(H=7.313,P=0.026)。65例中,PSV正常46例、偏低(PSV＜25 cm/s) 1例、偏高(PSV＞100 cm/s)18例;RI正常18例、偏低(RI＜0.5)11例、偏高(RI＞0.7)36例。36例出现OLT后并发症。以PSV_第7天诊断OLT后并发症的AUC为0.561,RI_第7天为0.699,PSV_第7天联合RI_第7天为0.732,与单独RI_第7天差异无统计学意义(Z=0.290,P＞0.05)。结论 利用床旁双功能超声监测移植肝动脉主干血流信号及RI可有效评估OLT后并发症。     

心肌梗死小鼠冠状动脉血流变化及其对评估梗死面积的意义

目的 探讨小鼠心肌梗死时冠状动脉血流动力学变化及其与梗死面积的相关性。方法 通过左冠状动脉前降支结扎建立小鼠心肌梗死模型14只,其中左冠状动脉前降支高位结扎7只(高位结扎组),低位结扎7只(低位结扎组);对另7只小鼠进行假手术操作(假手术组)。对3组均行超声生物显微镜(UBM)成像,测量左冠状动脉舒张期峰值血流速度(Vd)、平均血流速度(V_mean)和速度时间积分(VTI);并行组织病理学检查,测量心肌梗死面积(IS)。结果 高位结扎组及低位结扎组Vd、V_mean及VTI均较假手术组减低(P均<0.05),高位结扎组V_mean、VTI均低于低位结扎组(P均<0.05),高位结扎组与低位结扎组间Vd差异无统计学意义(P>0.05)。高位结扎组及低位结扎组IS均大于假手术组(P均<0.05),高位结扎组IS大于低位结扎组(P<0.05)。小鼠Vd、V_mean及VTI均与IS呈负相关(r=-0.557、-0.693、-0.672,P均<0.05)。结论 小鼠心肌梗死时冠状动脉血流动力学参数减低,且与组织病理学测量的IS呈负相关。     

Feasibility and diagnostic performance of fractional flow reserve measurement derived from coronary computed tomography angiography in real clinical practice

Non-invasive fractional flow reserve measured by coronary computed tomography angiography (FFR_CT) has demonstrated a high diagnostic accuracy for detecting coronary artery disease (CAD) in selected patients in prior clinical trials. However, feasibility of FFR_CT in unselected population have not been fully evaluated. Among 60 consecutive patients who had suspected significant CAD by coronary computed tomography angiography (CCTA) and were planned to undergo invasive coronary angiography, 48 patients were enrolled in this study comparing FFR_CT with invasive fractional flow reserve (FFR) without any exclusion criteria for the quality of CCTA image. FFR_CT was measured in a blinded fashion by an independent core laboratory. FFR_CT value was evaluable in 43 out of 48 (89.6?%) patients with high prevalence of severe calcification in CCTA images [calcium score (CS) >400: 40?%, and CS?>?1000: 19?%). Per-vessel FFR_CT value showed good correlation with invasive FFR value (Spearman’s rank correlation?=?0.69, P?<?0.001). The area under the receiver operator characteristics curve (AUC) of FFR_CT was 0.87. Per-vessel accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were 68.6, 92.9, 52.4, 56.5, and 91.7?%, respectively. Even in eight patients (13 vessels) with extremely severely calcified lesions (CS?>?1000), per-vessel FFR_CT value showed a diagnostic performance similar to that in patients with CS?≤?1000 (Spearman’s rank correlation?=?0.81, P?<?0.001). FFR_CT could be measured in the majority of consecutive patients who had suspected significant CAD by CCTA in real clinical practice and demonstrated good diagnostic performance for detecting hemodynamically significant CAD even in patients with extremely severe calcified vessels.     

FFRCT derived from computed tomography angiography: the experience in the UK

ABSTRACT

Introduction: Non-invasive fractional flow reserve derived from CT coronary angiography (FFR_CT) represents a novel technology to investigate coronary artery disease. The application of computational flow dynamics to anatomical data provides the clinician with a further functional assessment to inform decision-making in patients with coronary artery disease. In the UK FFR_CT has received medical technology approval for use since February 2017.

Areas covered: This article discusses the mathematical and physiological principles underpinning calculation of non-invasive fractional flow reserve (FFR), as well as discussing the differences between the commercially available technologies. Diagnostic accuracy, cost effectiveness and safety of non-invasive FFR from the early clinical trials is examined. Further to this the potential implications of the use of non-invasive FFR in clinical practice in the UK are discussed.

Expert commentary: Non-invasive FFR represents a promising comprehensive imaging technology providing both anatomical and physiological data to accurately diagnose obstructive coronary artery disease. The technology has yet to prove to be cost effective in ‘real world’ cohorts before becoming integrated into everyday clinical practice and guidelines in the United Kingdom.     

An angiographic technique for coronary fractional flow reserve measurement: in vivo validation

Fractional flow reserve (FFR) is an important prognostic determinant in a clinical setting. However, its measurement currently requires the use of invasive pressure wire, while an angiographic technique based on first-pass distribution analysis and scaling laws can be used to measure FFR using only image data. Eight anesthetized swine were instrumented with flow probe on the proximal segment of the left anterior descending (LAD) coronary arteries. Volumetric blood flow from the flow probe (Q_p), coronary pressure (P_a) and right atrium pressure (P_v) were continuously recorded. Flow probe-based FFR (FFR_q) was measured from the ratio of flow with and without stenosis. To determine the angiography-based FFR (FFR_a), the ratio of blood flow in the presence of a stenosis (Q_S) to theoretically normal blood flow (Q_N) was calculated. A region of interest in the LAD arterial bed was drawn to generate time-density curves using angiographic images. Q_S was measured using a time-density curve and the assumption that blood was momentarily replaced with contrast agent during the injection. Q_N was estimated from the total coronary arterial volume using scaling laws. Pressure-wire measurements of FFR (FFR_p), which was calculated from the ratio of distal coronary pressure (P_d) divided by proximal pressure (P_a), were continuously obtained during the study. A total of 54 measurements of FFR_a, FFR_p, and FFR_q were taken. FFR_a showed a good correlation with FFR_q (FFR_a = 0.97 FFR_q +0.06, r² = 0.80, p < 0.001), although FFR_p overestimated the FFR_q (FFR_p = 0.657 FFR_q + 0.313, r² = 0.710, p < 0.0001). Additionally, the Bland–Altman analysis showed a close agreement between FFR_a and FFR_q. This angiographic technique to measure FFR can potentially be used to evaluate both anatomical and physiological assessments of a coronary stenosis during routine diagnostic cardiac catheterization that requires no pressure wires.     

Quantification of fractional flow reserve based on angiographic image data

Coronary angiography provides excellent visualization of coronary arteries, but has limitations in assessing the clinical significance of a coronary stenosis. Fractional flow reserve (FFR) has been shown to be reliable in discerning stenoses responsible for inducible ischemia. The purpose of this study is to validate a technique for FFR quantification using angiographic image data. The study was carried out on 10 anesthetized, closed-chest swine using angioplasty balloon catheters to produce partial occlusion. Angiography based FFR was calculated from an angiographically measured ratio of coronary blood flow to arterial lumen volume. Pressure-based FFR was measured from a ratio of distal coronary pressure to aortic pressure. Pressure-wire measurements of FFR (FFR _P ) correlated linearly with angiographic volume-derived measurements of FFR (FFR _V ) according to the equation: FFR _P  = 0.41 FFR _V  + 0.52 (P-value < 0.001). The correlation coefficient and standard error of estimate were 0.85 and 0.07, respectively. This is the first study to provide an angiographic method to quantify FFR in swine. Angiographic FFR can potentially provide an assessment of the physiological severity of a coronary stenosis during routine diagnostic cardiac catheterization without a need to cross a stenosis with a pressure-wire.     

中国实验小型猪慢性心肌缺血模型的制备

目的探讨一种建立和评价慢性心肌缺血动物模型的简易方法。方法中国实验小型猪22头,开胸游离冠状动脉左回旋支主干,在左旋支近段放置Ameroid缩窄环,制作左旋支慢性闭塞的模型,术后5周行冠状动脉造影和心脏MR检查。结果22头中国实验小型猪中20头成活并成功建立慢性心肌缺血模型,应用Ameroid缩窄环后5周可见左旋支完全或次全闭塞,左旋支支配范围(左心室侧壁或下壁)心肌室壁增厚率及室壁运动幅度明显下降(P<0.01)。所有动物均示静息时和/或负荷后LCX支配范围内心肌灌注缺损。结论应用Ameroid缩窄环可以成功制作慢性心肌缺血的动物模型。     

The impact of image resolution on computation of fractional flow reserve: coronary computed tomography angiography versus 3-dimensional quantitative coronary angiography

Calculation of fractional flow reserve (FFR) based on computational fluid dynamics (CFD) requires reconstruction of patient-specific coronary geometry and estimation of hyperemic flow rate. Coronary computed tomography angiography (CCTA) and invasive coronary angiography (ICA) are two dominating imaging modalities used for the geometrical reconstruction. Our aim was to investigate the impact of image resolution as inherently associated with these two imaging modalities on geometrical reconstruction and subsequent FFR calculation. Patients with mild or intermediate coronary stenoses who underwent both CCTA and ICA were included. CCTA images were acquired either by 320-row area detector CT or by 128-slice dual-source CT. Two geometrical models were reconstructed separately from CCTA and ICA, from which FFR_CTA and FFR_QCA were subsequently calculated using CFD simulations, applying the same hyperemic flow rate derived from the ICA images at the inlet boundaries. A total of 57 vessels in 41 patients were analyzed. Average diameter stenosis was 43.4 ± 10.8 % by 3D QCA. Reasonably good correlation between FFR_CTA and FFR_QCA was observed (r = 0.71, p < 0.001). The difference between FFR_CTA and FFR_QCA was correlated with the deviation between minimal lumen areas by CCTA and by ICA (ρ = 0.34, p = 0.01), but not with plaque volume (ρ = ?0.09, p = 0.51) or calcified plaque volume (ρ = 0.01, p = 0.95). Applying the cutoff value of ≤0.8 to both FFR_CTA and FFR_QCA, the agreement between FFR_CTA and FFR_QCA in discriminating functional significant stenoses was moderate (kappa 0.47, p < 0.001). Disagreement was found in 10 (17.5 %) vessels. Acceptable correlation between FFR_CTA and FFR_QCA was observed, while their agreement in distinguishing functional significant stenosis was moderate. Our results suggest that image resolution has a significant impact on FFR computation.     

无创性检测心外膜血流变化评价冠脉侧支循环建立的实验研究

目的：应用冠脉血流显像观察前降支(LAD)近端慢性闭塞后其中远段以及后降支(PDA)血流的变化，探讨无创检测心外膜血流在评价侧支循环方面的意义。方法：24条实验小型猪，在前降支近端放置Ameroid环建立慢性心肌缺血模型。放环6周后做选择性左冠状动脉造影和心肌声学造影，观察放环处是否完全闭塞以及造影剂在左室心肌的分布情况。分别在基础状态及放环6周后，采用左心两腔切面观察前降支远段及后降支的血流信号，记录血流频谱。结果：14条动物成功建立模型。其中6条左室前壁见明显灌注缺损，冠脉血流显像未探及前降支中远段血流信号，后降支的峰值流速与基础状态无明显差异；8条前壁见不同程度造影剂充填，其中4条前降支远端可见前向性血流信号，2条前降支远端见逆向性血流信号，这8条猪的后降支峰值流速较基础时明显增快。结论：冠脉血流显像能直接检测冠脉闭塞后相关心外膜冠脉血流的改变，可作为判断侧支循环建立的重要依据。     

慢性冠状动脉狭窄及侧枝循环动物模型的建立

目的：建立慢性冠状动脉狭窄及侧枝循环动物模型,方法：健康小型猪10只,开胸游离冠状动脉左回旋支（LCX）主干,采用改良Ameroid缩窄器,制作左回旋支慢性狭窄及缺血后侧枝循环生成模型,术前与术后3周分别进行冠脉造影及超声心功能检查,结果：4只LCX完全闭塞,5只狭窄大于75％,心肌收缩及舒张功能明显下降,左前降支血管增粗,迂回,多支分支伸向缺血区形成血管网,无心肌梗塞表现,结论：采用Ameroid缩窄器可以成功地制作慢性冠状动脉狭窄及侧权循环形成的动物模型。     

Coronary Computed Tomography Angiography Derived Fractional Flow Reserve and Plaque Stress

Fractional flow reserve (FFR) measured during invasive coronary angiography is an independent prognosticator in patients with coronary artery disease and the gold standard for decision making in coronary revascularization. The integration of computational fluid dynamics and quantitative anatomic and physiologic modeling now enables simulation of patient-specific hemodynamic parameters including blood velocity, pressure, pressure gradients, and FFR from standard acquired coronary computed tomography (CT) datasets. In this review article, we describe the potential impact on clinical practice and the science behind noninvasive coronary computed tomography (CT) angiography derived fractional flow reserve (FFR_CT) as well as future applications of this technology in treatment planning and quantifying forces on atherosclerotic plaques.     

CTA诊断冠状动脉异常起源肺动脉

目的 探讨冠状动脉（简称冠脉）异常起源肺动脉（ACAPA）的CTA图像特征。方法 回顾性分析本院收治的24例ACAPA的患者资料,分析其CTA表现,并与手术结果对照。结果 24例患者中,发生于左冠脉20例（20/24,83.33%）、右冠脉1例（1/24,4.17%）、前降支1例（1/24,4.17%）、回旋支2例（2/24,8.33%）。冠脉异常起源部位：起源于肺动脉窦或肺动脉主干后壁11例（11/24,45.83%）、左壁7例（7/24,29.17%）、右壁4例（7/24,16.67%）,起源于左肺动脉2例（2/24,8.33%）。侧支循环：婴儿型5例,冠脉间未见侧支血管;成人型19例,其中左/右冠脉异常起源16例,前降支异常起源1例,回旋支异常起源2例。合并双前降支和冠脉在升主动脉壁内走行各1例。外科手术19例。术后CTA复查5例,1例人工管道与回旋支吻合口局限性狭窄,1例右心室流出道再狭窄,1例冠脉假性动脉瘤。结论 CTA可清晰显示冠脉异常起源部位、与升主动脉的距离、侧支血管、合并其他冠脉畸形,有助于术前制定手术方式及术后随访。