心房颤动对双源CT冠状动脉血管成像的影响

目的探讨心房颤动（房颤）平均心室率、心率波动和心率变异性对冠状动脉CT血管成像（CTA）图像质量的影响。方法87例房颤患者和107例心律正常者进行了双源CT冠状动脉血管成像。平均心室率、心率波动和心率变异性与图像质量之间的关系采用相关分析和线性回归分析判断,各分段图像质量之间的差别采用卡方检验和非参数检验。结果房颤组共1218段血管纳入分析,达到诊断标准的血管共1038段（85．2％）。房颤组的平均心室率为（90．1±22．0）次／min,心率波动为（55．8±34．3）次／min,心率变异性为0．55±0．29,均高于对照组（P〈0．01）。部分动脉图像质量与平均心率无关（P〉0．05）。除左主干外,心率波动与其他分段图像质量呈负相关（P〈0．01）。心率变异性与所有分段图像质量呈负相关（0．01〈P〈0．05和P〈0．01）。左主干和回旋支近段高质量图像百分率较高,而后降支和钝缘支图像质量较差。结论双源CT能对大多数房颤患者冠状动脉进行评价,其获得的各近段动脉图像质量高于远段动脉。心率波动对房颤冠状动脉CTA图像质量起主导影响作用。     

体模实验优化64层螺旋CT冠状动脉成像参数设置

目的探讨改善64层螺旋CT冠状动脉图像质量的条件。方法在不同的心率、不同重组算法、图像重组相位窗下，用心脏冠状动脉模具评价64层螺旋CT冠状动脉图像质量。结果心率小于70次／分，心率波动范围小于10次／分时图像质量最佳；图像质量在R—R间期的75％相位（舒张中期）最好；实验数据共108组，采用单扇区、双扇区、四扇区重组成功率分别为93．5％，91．6％，93．4％，组间差异无统计学意义（r：4．163，P=0．125）。优良率分别为81．8％，79．2％和84．1％。结论心率、重组算法和图像重组相位窗是影响多层螺旋CT冠状动脉成像的主要参数，运用合适参数能获得更优质图像。     

16层螺旋CT冠状动脉造影中心率对图像质量的影响

对138例疑诊冠心病患者行16层螺旋CT冠状动脉造影（MSCTCA）检查，其中心率〈60次／min者40例（A组）、60～65次／min者30例（B组）、65～70次／min者36例（C组）、〉700次／min者70例（D组），根据冠状动脉伪影多少及血管连续性评价各组重建图像质量。结果A、B、C、D组左冠状动脉及其分支的检查成功率分别为95％、93．3％、83．3％和50％，右侧冠状动脉分别为90％、93．3％、77．8％和50％，D组各冠状动脉节段检查成功率均显著低于其他三组（P〈0．05）。认为冠状动脉MSCT检查前心率调整〈65次／min即可获得较高的成功率；保持检查过程中心率稳定（变化〈30次／min）有助于提高检查成功率。     

第二代双源CT Flash Spiral模式高心率冠状动脉成像的图像质量及准确性评价

目的评价第二代双源CT大螺距前瞻性螺旋扫描（Flash Spiral）高心率冠脉成像的图像质量、准确性及有效射线剂量。方法前瞻性入选心率〉65次／min的连续性患者268例,随机分为两组。A组134例,采用Flash Spiral模式扫描,采集图像时间为RR间期20％-30％;B组134例,采用回顾性心电门控扫描模式（Spiral）扫描。30d内A组有47例行冠状动脉造影术（CCA）检查（A1组）,B组中有45例行CCA检查（B1组）。比较两组患者一般情况、图像质量评分、图像噪声、对比信噪比（CNR）和有效射线剂量。以CCA结果为金标准,分别计算A1、B1两组FlashDSCT显示冠脉病变的敏感性、特异性、准确率、阳性预测值和阴性预测值。结果①两组患者一般情况比较差异无统计学意义。②两组不可诊断节段基于血管节段评价分别为1．52％和1．74％,基于患者评价分别为7．5％和6．7％,差异均无统计学意义（P=0．345,P=0．812）。两组图像质量评分均数分别为1．064±0．306和1．084±0．327,差异无统计学意义（P=0．063）。A组平均图像噪声19±27（21．4±4．5）HU,CNR6．4-25．3（12．1±4．2）：B组分别为19±28（20．9±4.3）HU和7．1-28．2（13．8±5．1）,两组比较差异无统计学意义。③心率变异性：A组图像质量评分3分的病例平均心率变异性明显小于B组。④与CCA比较,两组患者评价冠状动脉狭窄的敏感性、特异性差异均无统计学意义。⑤射线剂量：A组平均有效射线剂量显著低于B组[（1．04±0．16）mSv比（7．05±1．05）mSv,P=0．001]。结论高心率患者（心率〉65次／min）采用Flash双源CT大螺距前瞻性心电门控螺旋扫描在RR间期20％±30％成像,图像质量、准确性与回顾性心电门控扫描接近,而有效射线剂量显著减低。心率变异性对高心率患者FlashSpiral模式扫描图像质量的影响较大。     

心率及心率波动对256层CT回顾性心电门控冠状动脉成像质量的影响简

目的 探讨心率及心率波动对256层计算机断层扫描（computerized tomography,CT）冠状动脉成像图像质量的影响.方法 150例疑为冠状动脉粥样硬化性心脏病（冠心病）的患者行256层CT回顾性心电门控冠状动脉检查,对直径＞1.5 mm的冠状动脉节段进行评分.根据平均心率分为3组：A组,心率＜65次/min;B组,65次/min～80次/min;C组,心率≥80次/min.比较不同心率组间的图像质量,采用Pearson相关分析方法分析平均心率及心率波动对图像质量的影响,并采用线性回归方程确定需进行干预的心率临界点.结果 在最佳重组时相上,可满足诊断要求的图像占97.9％.冠状动脉总体、右冠状动脉、左前降支及左旋支的图像质量评分与心率显著相关,相关系数分别为0.473、0.425、0.409、0.413（P均＜0.001）,冠状动脉图像质量与心率波动无明显相关（P＞0.05）.不同心率组间冠状动脉图像质量比较,差异有统计学意义（P＜0.05）.当心率＜83.1次/min时,可获得优良的图像质量,而为获取满足临床诊断要求的图像,心率应＜119.1次/min.心率＜65次/min时,舒张期重建的图像质量佳;心率＞71次/min时,收缩期重建的图像质量佳.结论 心率波动对256层CT同顾性心电门控冠状动脉图像质量无显著影响,但心率仍是影响图像质量的一个重要因素;降低心率有助于提高图像质量.     

经皮腔内冠状动脉成形术中冠状动脉阻塞对心率变异性的影响

对冠脉造影确诊冠心病而行经皮腔内冠状动脉成形术（PTCA）治疗的20例患者，采用心率变异性（HRV）频域法分析PTCA术球囊充气冠脉阻塞前、后患者的HRV，以评价PTCA米冠脉急性闭塞时心脏自主神经功能状况的变化，及与冠脉阻塞部位的关系。其中前降支组13例，右冠状动脉组7例。结果表明；PTCA术冠状动脉阻塞时前降支组HRV指标中的低频段（LFP）显著增高（267．36±21．30升至341．19±26．42bpm2／Hz，P＜0．05），说明HRV降低，右冠状动脉组的HRV虽有所增大，但未达统计学意义（P＞0．05）。提示PTCA术中HRV的变化可能与球囊扩张冠脉部位有关。     

非体外循环与常规冠状动脉旁路移植术治疗重症冠心病的对比分析

目的：探讨重症冠心病患者非体外循环下冠状动脉旁路移植术（OPCAB）的可行性和优越性。方法：回顾性分析425例重症冠心病的冠状动脉旁路移植术临床资料。其中非体外循环下冠状动脉旁路移植术（OPCAB组）268例,占63．1％;常规体外循环下冠状动脉旁路移植术（CCABG组）157例。比较两组术后早期死亡率及合并症的发生情况。结果：OPCAB组搭桥（4．09±0．75）支／人,CCABG组搭桥（4．17±0．86）支／人（P〉0．05）。两组新发心房纤颤、围术期心肌梗塞、肾功能不全、肺部并发症发生率差异无显著性（P〉0．05）。与CCABG组比较,OPCAB组手术死亡率、呼吸机使用时间、ICU停留时间、术后输血量、二次开胸率、神经系统并发症发生率明显降低或减少（P〈0．05～〈0．01）。结论：非体外循环下冠状动脉旁路移植术在重症冠心病患者中安全可行,临床效果好。     

双源CT两种冠状动脉造影扫描方法及辐射剂量对比研究

目的优化双源CT冠状动脉成像的扫描方案,降低患者冠状动脉成像的辐射剂量。方法分析268例心率规律且小于70次／min双源CT冠状动脉成像患者病例资料,前瞻性心电门控及回顾性心电门控检查患者各134例,观察两者成像质量,比较两者单次扫描CT容积剂量指数（CTDIvol）及剂量长度乘积（DLP）。结果在扫描范围、对比剂种类速率和注射部位完全相同的情况下,前瞻性心电门控组质量评分（3．71±0．52）分,回顾性心电门控组质量评分（3．78±0．36）分,P〉0．05。前瞻性心电门控组和回顾性心电门控组在CTDIvol分别为（14．02±0．02）、（79．50±10．09）mGy;有效辐射剂量分别为（3．38±0．28）、（23．84±4．35）mSv,P均〈0．05。结论在心率规律且小于70次／min的患者行前瞻性心电门控冠状动脉成像,可有效地降低患者的辐射剂量,减轻辐射损伤。     

尼可地尔对经皮冠状动脉介入治疗后心绞痛合并2型糖尿病患者的疗效

目的评价尼可地尔对经皮冠状动脉介入（percutaneous coronary intervention,PCI）治疗后再发心绞痛合并2型糖尿病患者的疗效和安全性。方法选取PCI治疗后再发心绞痛合并2型糖尿病患者60例．随机（电脑随机数字表法）分为两组,两组均给予常规治疗。试验组使用尼可地尔．对照组在常规治疗的基础上给予单硝酸异山梨酯片治疗。结果治疗1周后,试验组心绞痛发作次数[（6．5±2．8）次弧（10．2±4．8）次,P〈0．05]、持续时间[（1．5±0．9）min vs．（2．4±2．3）min,P〈0．05]、显效率[80．0％（24／30）vs.53．3％（16／30）,P〈0．05],心电图改善[80．0％（24／30）vs.40％（12／30）,P〈0．05]均优于对照组,差异有统计学意义（P〈0．05）。试验组出现轻中度头痛2例,对照组出现轻中度头痛4例,两组比较差异有统计学意义（P〈0．05）。两组均无明显低血压发生,对血糖也无明显影响。结论尼可地尔能明显降低冠状动脉粥样硬化性心脏病（冠心病）合并2型糖尿病患者PCI治疗后再发心绞痛的发生风险。     

静息心率对冠脉慢性闭塞冠脉介入术血管再通率的影响

目的：了解静息心率（RHR）与冠状动脉慢性完全闭塞（CCT0）病变经皮冠状动脉介入术（PCT）成功率的关系。方法：人选2002年1月1日至2008年12月1日在我院及桂林医学院附属医院接受支架植人术的CCTO患者85例,根据入院时静息心率（RHR）分为RHR1（〈70次／min）、RHR2（70～79次／min）、RHR3（80～89次／min）和RHR4（≥90次／min）四组,比较不同组间血管即刻开通率。结果：76％（65／85）的患者成功完成了冠状动脉内支架植人术,4组血管即刻开通率分别是,RHR1：90％（18／20）,RHR2：91％（20／22）。RHR3：63％（12／19）,RHR4：63％（15／24）,4组间有显著性差异（x^2=9．058,P〈0．05）;RHR1与RHR2,RHR3与RHR4间无显著差异（P均〉0．05）,但RHR1与RHR3,RHR1和RHR4,RHR2与RHR3,RHR2与RHR4间有显著差异（P均〈O．05）,RHRl和RHR2组的即刻开通率显著高于RHR3和RHR4组（P〈0．05）。结论：静息心率对冠状动脉慢性完全闭塞病变经皮冠状动脉介入术成功率有影响,静息心率越低手术成功率越高。     

Multidetector-row computed tomography coronary angiography: optimization of image reconstruction phase according to the heart rate.

BACKGROUND: To optimize the image reconstruction phase of multidetector-row computed tomography (MDCT) coronary angiography according to the heart rate is crucial. METHODS AND RESULTS: Scan data were reconstructed for 10 different phases in 58 sequential patients who underwent 8-row cardiac MDCT. The obtained images were scored and compared in terms of motion artifacts and visibility of the vessels, and moreover, ECG record-based evaluations were added for clarification of the temporal relationships among these 10 phases. In the cases with lower heart rates (<65 beats/min), the best quality images were obtained when the end of the image reconstruction phase was positioned at the peak of the P wave. In some cases with higher heart rates (>65 beats/min), they were obtained in the late systolic period. CONCLUSION: As the heart rate increased, the optimal image reconstruction phase changed from mid diastole to late systole. However, it is recommended to try to decrease the heart rate of patients before data acquisition.     

二维彩色多普勒超声检测右冠状动脉的初步探讨

目的探讨应用二维彩色多普勒超声检测右冠状动脉.方法 100例病人使用二维彩色多普勒超声探测右冠状动脉.比较其检出率、收缩期及舒张期可视段的长度和宽度,各组右冠状动脉壁的最低回声强度与其周围组织最低回声强度之间的差值.结果冠心病病人的右冠状动脉检出率低;右冠状动脉在收缩期可视段宽度比舒张期长;在舒张期其可视长度比收缩期长.冠心病病人的右冠状动脉壁最低回声强度与其周围组织的差值最大.结论二维彩色多普勒超声是诊断冠状动脉疾病的首选方法之一.     

The effect of cardiac contraction on collateral resistance in the canine heart.

We determined whether the coronary collateral vessels develop an increased resistance to blood flow during systole as does the cognate vascular bed. Collateral resistance was estimated by measuring retrograde flow rate from a distal branch of the left anterior descending coronary artery while the main left coronary artery was perfused at a constant pressure. Retrograde flow rate was measured before and during vagal arrest. We found that in 10 dogs the prolonged diastole experienced when the heart was stopped caused no significant change in the retrograde flow rate, which indicated that systole has little effect on the collateral resistance. However, when left ventricular end-diastolic pressure was altered by changing afterload or contractility, a direct relationship between end-diastolic pressure and collateral resistance was noted.     

心率及心率波动对64层螺旋CT冠状动脉成像质量的影响

目的回顾性分析心率及心率波动对64层螺旋CT冠状动脉图像质量的影响。方法将129例疑为冠心病的患者行64层螺旋CT冠状动脉检查的原始数据在心动周期的40%～80%时相上进行图像重组。对直径>1.5mm冠状动脉节段进行评分(≤3分为满足临床诊断)。采用Pearson相关分析方法分析平均心率及心率波动对图像质量的影响。结果扫描时所有患者心率33～108次/min,平均62.2次/min。心率波动0.2～46.9次/min,平均4.4次/min。在最佳重组时相上,可满足诊断的图像占93.9%。图像质量与平均心率及心率波动显著相关。心率<69.7次/min及心率波动<15.7次/min时,可获得优良的图像质量;心率<63次/min时,舒张期重组的图像质量佳;心率>67次/min时,收缩期重组的图像质量佳。重组时相窗从舒张期切换至收缩期的心率范围为63～67次/min。结论心率及心率波动对64层螺旋CT冠状动脉图像质量有重要影响,减低心率及心率波动可提高图像质量。     

Dual-Source Computed Tomographic Coronary Angiography: Image Quality and Stenosis Diagnosis in Patients with High Heart Rates

We sought to evaluate prospectively the effects of heart rate and heart-rate variability on dual-source computed tomographic coronary image quality in patients whose heart rates were high, and to determine retrospectively the accuracy of dual-source computed tomographic diagnosis of coronary artery stenosis in the same patients.We compared image quality and diagnostic accuracy in 40 patients whose heart rates exceeded 70 beats/min with the same data in 40 patients whose heart rates were 70 beats/min or slower. In both groups, we analyzed 1,133 coronary arterial segments. Five hundred forty-five segments (97.7%) in low-heart-rate patients and 539 segments (93.7%) in high-heart-rate patients were of diagnostic image quality. We considered P < 0.05 to be statistically significant. No statistically significant differences between the groups were found in diagnostic-image quality scores of total segments or of any coronary artery, nor were any significant differences found between the groups in the accurate diagnosis of angiographically significant stenosis.Calcification was the chief factor that affected diagnostic accuracy. In high-heart-rate patients, heart-rate variability was significantly related to the diagnostic image quality of all segments (P = 0.001) and of the left circumflex coronary artery (P = 0.016). Heart-rate variability of more than 5 beats/min most strongly contributed to an inability to evaluate segments in both groups. When heart rates rose, the optimal reconstruction window shifted from diastole to systole.The image quality of dual-source computed tomographic coronary angiography at high heart rates enables sufficient diagnosis of stenosis, although variability of heart rates significantly deteriorates image quality.Key words: Artifacts, coronary angiography/methods, coronary stenosis/diagnosis/radiography, diastole/physiology, heart rate/physiology, image processing, computer-assisted, prospective studies, radiographic image interpretation, computer-assisted, sensitivity and specificity, systole/physiology, technology assessment, biomedical, tomography, spiral computed/instrumentation/methods/standardsDuring the past few years, noninvasive coronary angiography upon multidetector-row computed tomography (MDCT) has rapidly progressed and has shown promise with regard to the detection and quantification of coronary artery stenosis.^1–4 However, despite the increase in temporal resolution from 16- to 64-detector-row computed tomography (CT), coronary CT angiography remains sensitive to motion artifacts, which occur especially at higher heart rates.^2,5–7 Results of a study³ of 64-detector-row CT coronary angiography showed a nonsignificant tendency toward lower image quality at higher mean heart rates, and a significant negative relation between image quality and heart-rate variability. In order to reduce motion artifacts, it has been proposed that patients be administered oral β-blocker medication for heart-rate control, even when 64-detector-row CT is to be used.^8–11 In most studies that have involved 16- or 64-detector-row CT, the target for scanning has been maintained at heart rates slower than 70 or even 60 beats/min, so that good-quality images of coronary arteries could be obtained. The requirement to premedicate patients with β-blocker drugs in order to achieve a sufficiently low heart rate for scanning has been considered a major limitation surrounding the clinical use of MDCT coronary angiography.Dual-source CT (DSCT) coronary angiography incorporates 2 X-ray tubes and 2 detectors that are mounted onto a rotating gantry, with an angular offset of 90°.¹² The DSCT system affords a high temporal resolution of 83 ms in monosegment reconstruction mode. In contrast with single-source CT systems that rely on multisegment reconstruction techniques, temporal resolution upon DSCT is independent of heart rate. Initial studies have shown that DSCT enables the study of coronary arteries with excellent diagnostic quality in all patients, independent of heart rate—thus obviating the need to premedicate patients with β-blockers.^12–15 We believed that the effects of heart rate and heart-rate variability on image quality, diagnostic accuracy, and optimal reconstruction windows merited further evaluation in patients whose heart rates exceeded 70 beats/min.The aim of this study was to evaluate prospectively the effect of heart rate and heart-rate variability on DSCT image quality in patients who had high heart rates, and to determine retrospectively the accuracy of DSCT in the diagnosis of coronary artery stenosis, using invasive coronary angiography as the reference standard.     

不完全与完全心肌桥-壁冠状动脉的CT影像特征分析

目的 对比评价不完全与完全心肌桥-壁冠状动脉(MB-MCA)的CT影像学特征.方法 回顾性分析50例显示有MB患者的双源CT冠状动脉血管成像(DSCTA)资料,将其分为不完全MB-MCA组(MCA被心肌部分包绕,至少在1/2以上)和完全MB-MCA组(MCA完全被心肌包绕),分别在其最佳收缩期及舒张期测量MCA及其近远侧血管的管径变化,计算MCA狭窄率,并记录MB近侧血管发生粥样硬化情况.结果 50例患者中,DSCTA显示58处MB,平均长度为(2.02±1.02)cm,其中不完全MB 23处,完全MB 35处,前降支中段32处(55.2%),前降支远段17处(29.3%),前降支近段1处,第一对角支3处,钝缘支4处,右冠状动脉远段1处.不完全MB-MCA舒张期及收缩期管径、狭窄率分别为(1.93±0.49)mm、(1.71±0.45)mm和25.21%±21.02%,完全MB-MCA舒张期及收缩期管径、狭窄率分别为(2.21±0.41)mm、(1.63±0.52)mm和10.38%±20.2%.两型MB-MCA管径变化(t=2.76,P=0.008)及MCA狭窄率(t=2.667,P=0.01)差异有统计学意义.8处(34.78%)不完全MB及15处(42.86%)完全MB近侧血管发生粥样硬化,两者之间差异无统计学意义(x2=0.378,P＞0.05).结论 DSCTA能够清晰的显示不完全和完全MB,并能准确评价MB-MCA在舒张期和收缩期的形态学变化及MB近侧血管发生粥样硬化的情况.

Abstract：

Objective To evaluate the CT imaging characteristics of incomplete and complete myocardial bridges-mural coronary artery(MB-MCA). Methods Fifty subjects with dual source coronary CT angiography(DSCTA)evidenced MB were included. The subjects were divided into incomplete MBMCA and complete MB-MCA groups. The diameter of MCA in best systole phase and diastole phase, the MCA stenosis rate, the presence of atheromatous change proximal to the MB were evaluated. Results There were 58 MB, the average length was(2. 02 ± 1.02)cm, 23 were incomplete MB and 35 were complete MB.Thirty-two MB were in the middle segments of left anterior descending artery(55.2%);17 MB were in the distal segment of the left anterior descending artery(29. 3%);1 MB was in the proximal segment of left anterior descending artery;3 MB in diagonal branch;4 MB in obtuse marginal branch, 1 MB in distal right coronary artery. It was statistically significant difference between the incomplete MB-MCA and the complete MB-MCA of the diameter change in diastole and systole phase[(1.93 ±0. 49)mm,(1.71 ±0. 45)mm vs.(2.21 ±0.41)mm,(1.63 ±0.52)mm, P=0.008]and stenosis rate(10.38%±20.2%vs. 25.12% ±21.02%, P = 0. 01). Atherosclerotic finding was evidenced in 8 incomplete MB(34. 78%)and 15complete MB(42. 86%)at the proximal vessel of mural coronary artery(P ＞ 0. 05). Conclusion DSCTA can vividly display the incomplete and complete myocardial MB, accurately evaluate the shape change of MB-MCA in diastole and systole phase and detect the atherosclerotic change in the proximal vessel of MB.     

冠状动脉造影检查对心肌桥的诊断价值

目的 探讨冠状动脉造影检查对心肌桥诊断的应用,研究心肌桥和冠状动脉粥样硬化的相关性.方法 收集1523例患者冠状动脉造影检查资料,分析心肌桥检出率,观察心肌桥的发生位置、壁冠状动脉收缩期狭窄程度、心肌桥血管合并粥样斑块的位置、斑块处管腔狭窄程度.结果 全部1523例患者中,201例患者检查结果正常,1225例患者检出粥样斑块,231例患者检出心肌桥.心肌桥检出率为15.2％,共检出心肌桥235处.心肌桥位置：右冠状动脉1处,左主干1处,旋支1处,对角支3处,左前降支229处,以左前降支中段多见,壁冠状动脉收缩期轻度狭窄为主.纯心肌桥97例.134例患者心肌桥血管合并粥样斑块144处,斑块位置：心肌桥近端111处,心肌桥段19处,心肌桥远端14处.心肌桥近端血管粥样硬化较心肌桥段、心肌桥远端发生率高,但粥样斑块的形成与壁冠状动脉收缩期的狭窄程度无显著相关（P＞0.05）.结论 心肌桥多见于左前降支中段血管,壁冠状动脉收缩期多为轻度狭窄,血管合并粥样硬化,多见于心肌桥前端,但粥样斑块的形成与壁冠状动脉收缩期狭窄程度无明显相关性.冠状动脉造影检查对心肌桥及心肌桥合并粥样硬化的诊断有重要价值.     

心率及心率变化对双源CT冠状动脉成像图像质量影响分析

目的:探讨心率及心率变化对双源CT(dual-source CT,DSCT)冠状动脉成像图像质量的影响。方法:回顾性分析124例双源CT冠状动脉成像资料,按心率及心率变化分组,比较不同组间冠状动脉各节段图像质量差异。结果:DSCT冠状动脉成像图像质量与心率有关,低心率组和中心率组间图像质量分级无明显差异,低心率组和高心率组间及中心率组和高心率组间图像质量分级均有显著性差异。检查过程中出现心率变化对图像质量无显著影响。结论:双源CT冠状动脉成像不受心率及心率变化限制,高心率时图像质量有下降,但不影响诊断。