肺动脉栓塞是严重威胁人类健康的疾病，已成为我国常见心血管系统疾病，在欧美国家也是三大常见致死性心血管系统疾病，而深静脉血栓，尤其是下肢深静脉血栓是肺动脉栓塞的主要原因［1-2］。从某种程度上讲，深静脉血栓和肺动脉栓塞是一种疾病的两个不同阶段，有关肺动脉栓塞的流行病学研究主要集中在发病率、诊断率、病死率、治疗方式有效率等方面［3］，关于肺动脉各分支血管的受累概率及不同下肢静脉血栓引起肺栓塞的概率很少有文献涉及。笔者主要就这两方面的概率进行研究，旨在为临床医师诊断肺动脉栓塞提供参考资料，并希望能够对肺栓塞的定位治疗起到一定参考作用。

患者男，28岁，于3个月前突发胸痛，程度较为剧烈，伴有胸闷、心悸，就诊于外院发现心脏杂音。行心脏彩色超声（彩超）示：主动脉右冠状动脉窦窦瘤破裂（破入右心室）。此后胸痛消失，偶有心悸，无胸闷，无活动后气短，未系统诊治。于2014年1月3日为治疗主动脉窦瘤破裂（RSVA）就诊于吉林大学第二医院。查体：双肺呼吸音清，未闻及干、湿啰音及胸膜摩擦音。心前区无异常隆起，无抬举性心尖搏动，胸骨左缘第2～3肋间可触及连续性震颤，心尖搏动位于第5肋间锁骨中线内0.5 cm处；叩诊心浊音界无扩大，心率90次/min，节律规整，心音有力，胸骨左缘第2～3肋间可闻及较粗糙的连续性机器样杂音，并向剑突传导，余各瓣膜听诊区未闻及杂音，未闻及额外心音。二维超声心动图及M型超声心动图示：各心腔及大血管内径基本正常。主动脉右冠状动脉窦向右心室流出道膨出，范围约1.8 cm×1.2 cm，瘤壁见多个破口，较大破口内径约为0.8 cm，见连续分流频谱，速度452 cm/s，压差82 mmHg（1 mmHg=0.133 kPa），余各瓣膜形态、回声、活动未见异常，房室间隔回声连续。影像诊断：主动脉右冠状动脉窦窦瘤破裂（破入右心室），主动脉瓣轻度反流。心电图示：窦性心律，心电轴不偏，左心房、左心室肥厚。血常规、凝血常规、心肌损伤标志物、肝功能、肾功能、电解质、血糖、血脂、心肌酶、尿常规、免疫常规、便常规+隐血、甲状腺功能三项等各项指标未见明显异常。综合以上临床资料可明确诊断为RSVA（破入右心室）。决定对患者实施经皮主动脉窦瘤介入封堵术。

Objectives To evaluate the performance of dual source computed tomography coronary angiography(DSCTCA) for detecting in-stent restenosis in small coronary arteries.Methods Totally 76 patients(59 males,17 females) with chest pain were prospectively evaluated by DSCT-CA after coronary stent implantation within 6-12 months.The patients were divided into different groups according to heart rate and the results of coronary angiography : heart rate≤ 70 bite / min group [n=48,heart rate(58±5) bite / min] and heart rate ﹥ 70 bite / min group [n=41,heart rate(78± 9) bite / min];simple group(single stent,n =54) and complex group(overlapping stents and bifurcation stent,n = 35);right coronary group(n =33),left circumflex coronary artery group(n =43) and left anterior descending group(n=13).Sensitivity,specificity,positive predictive value(PPV) and negative predictive value(NPV) of DSCT-CA in different groups were compared.Results Totally 89 stents were implanted in 76 patients and 31.4%(28 / 89) of them were proven restenosis.Sensitivity,specificity,PPV and NPV of DSCT-CA calculated in all stents were 89%,87%,76% and 95% respectively.DSCT-CA diagnostic performance of herat rate ≤70 bite / min group and heart rate ﹥ 70 bite / min group had no significant difference(P 0.05).DSCT-CA diagnostic performance in three main coronary branches was similar to each other(P0.05).Sensitivity,PPV,specificity,NPV of DSCT-CA in complex group was significantly lower than those in simple group(83% vs.94%,P0.05;63% vs.88%,P0.05;74% vs.95%,P0.05;89% vs.97%,P0.05;respectively).Within simple group,sensitivity was similar to specificity(94% vs.95%,P 0.05) and PPV was significantly lower than NPV(88% vs.97%,P0.05).Quality control chart showed that ratio of DSCT-CA detection for in-stent restenosis in small coronary arteries was increased year by year.Ratios in 2006 and 2007 were lower than average level and ratio in 2009 was twice higher than average level.Conclusions DSCT-CA can be the screening method for detecting in-stent restenosis in small coronary arteries,of which,negative individuals can be screened out of in-stent restenosis and positive individuals should perform coronary angiography for accurate diagnosis.