Non-invasive evaluation of coronary artery stent patency with retrospectively ECG-gated 64-slice CT angiography

The aim of our study has been to evaluate the ability of 64-slice computed tomographic angiography (CTA) to assess coronary artery stent patency, relative to selective coronary angiography (SCA). Fifty-five consecutive patients (age range 45–80 years) with 97 previously implanted coronary artery stents underwent 64-slice CTA. The 55 patients comprised 40 subjects (group A) who were referred for follow-up SCA at a mean interval of 9.6 months after stent positioning, and 15 subjects (group B) in whom SCA was clinically indicated. Stent evaluation was performed independently by two blinded readers in terms of image quality and presence of in-stent restenosis (ISR; lumen obstruction of ≥50%). SCA was performed in 41/55 patients; 14 patients refused to undergo SCA after the 64-slice CTA exam. A total of 88 stents in 74 segments were analyzed. Twenty-one of the 74 stented segments were of poor image quality and were not considered for further analysis. Sixty-four-slice CTA detected 12/16 ISR (sensitivity: 75%) and ruled out ISR in 32/37 cases (specificity: 86%). Sixty-four-slice CTA is a valuable modality for follow-up of coronary artery stent patency only in selected patients. Appropriate candidates for follow-up 64-slice CTA should be established based on stent diameter, stent material and type as well as HR and heart rhythm. However, given the number of non-assessable segments, further work would appear necessary before 64-slice CTA can be considered a suitable procedure for broad clinical application in the evaluation of coronary artery stent patency.     

64层螺旋CT在冠状动脉支架置入术后评估中的价值

目的:评价64层螺旋CT在冠状动脉支架置入术后复查中的临床价值。方法:采用64层螺旋CT对27例冠状动脉支架置入术后的患者(共47个支架)进行CT冠状动脉成像。观察支架及其支架血管和非支架血管的通畅性。结果:支架通畅43例,支架内狭窄3个、闭塞1个,支架前后血管狭窄25支(包括两近端狭窄4例),非支架血管狭窄26支。结论:64层螺旋CT比16层螺旋CT观察冠状动脉内支架优越,可作为冠状动脉支架置入术后效果随访观察和了解原有冠心病进展情况的重要手段。     

64层螺旋CT冠状动脉成像临床应用评价

目的:评价64层螺旋CT冠状动脉成像(64SCTCA)的图像质量和在诊断冠状动脉疾病的临床价值。方法:搜集35例患者64SCTCA的完整资料,并以近期实施的选择性X线冠状动脉成像(SCA)结果为金标准进行对比,对64SCTCA显示的冠状动脉主支及主要分支情况进行分级评估。结果:35例病例可用于评估的冠状动脉共计368支,成功率达95.6%。其中SCA共显示74个节段冠脉有中、重度狭窄(≥50%)。MSCTCA诊断中重度狭窄的敏感性为86.5%,特异性为97.3%,阳性预测值88.9%,阴性预测值96.6%。经配对χ2检验,P>0.05,证明两种检查方法在发现冠状动脉病变方面差异无统计学意义。结论:64层螺旋CT冠状动脉成像是一种无创、快速的成像方法,对诊断冠状动脉≥50%狭窄有较高的敏感性和特异性,适合用于临床怀疑冠心病的患者SCA前的筛选检查。     

Influence of cardiac hemodynamic parameters on coronary artery opacification with 64-slice computed tomography

The purpose of this study was to evaluate the influence of ejection fraction (EF), stroke volume (SV), heart rate, and cardiac output (CO) on coronary artery opacification with 64-slice computed tomography (CT). Sixty patients underwent, retrospectively, electrocardiography-gated 64-slice CT coronary angiography. Left ventricular EF, SV, and CO were calculated with semi-automated software. Attenuation values were measured and contrast-to-noise ratios (CNRs) were calculated in the proximal right coronary artery (RCA) and left main artery (LMA). Mean EF during scanning was 61.5±12.4%, SV was 63.2±15.6 ml, heart rate was 62.5±11.8 beats per minute (bpm), and CO was 3.88±1.06 l/min. There was no significant correlation between the EF and heart rate and the attenuation and CNR in either coronary artery. A significant negative correlation was found in both arteries between SV and attenuation (RCA r=−0.26, P<0.05; LMA r=−0.34, P<0.01) and between SV and CNR (RCA r=−0.26, P<0.05; LMA r=−0.26, P<0.05). Similarly, a significant negative correlation was found between the CO and attenuation (RCA r=−0.42, P<0.05; LMA r=−0.56, P<0.001) and between the CO and CNR (RCA r=−0.39, P<0.05; LMA r=−0.44, P<0.001). The actual hemodynamic status of the patient influences the coronary artery opacification with 64-slice CT, in that vessel opacification decreases as SV and CO increase.     

冠状动脉变异的64层螺旋CT诊断价值

目的 探讨64层螺旋CT(64-MSCT)对冠状动脉变异(CAA)的诊断价值及预后评估.方法 收集我院行64-MSCT心脏检查诊断为冠状动脉变异患者44例,对原始图像进行最大密度投影(MIP)、曲面重建(CPR)、多平面重建(MPR)、立体重建(VR)和血管探针等后处理重建,分析各型冠状动脉变异的形态学特征.结果 冠状动脉起源异常共7例:1例左冠状动脉源于右冠状窦,2例有冠状动脉源于左冠状窦,1例右冠状动脉起源于后冠状窦,2例冠状动脉高位开口于主动脉壁,1例右冠状动脉起源于肺动脉.32例心肌桥-壁冠状动脉(其中1例同时有冠状动脉高位开口);5例冠状动脉发育不良.1例左回旋支未发育.结论 64-MSCT能准确显示冠状动脉变异的解剖细节,对其形态学评价具有突出优势,有重要诊断价值.     

64层螺旋CT在冠状动脉疾病诊断中的价值

目的 评价64层螺旋CT冠状动脉成像（64SCTCA）在诊断冠状动脉疾病的临床价值。方法 搜集100例患者64SCTCA的完整资料，并以近期实施的选择性X线冠状动脉成像（CCA）结果为金标准进行对比，对64SCTCA显示的冠状动脉主支及主要分支情况进行分级评估。结果 所有病例可用于评估的920支冠状动脉中，共显示病变370支，其中348支得到CCA证实；22支64SCTCA诊断狭窄而CCA显示正常，另外有10例CCA确诊存在的病变而在64SCTCA上未能显示，得出64SCTCA诊断冠状动脉病变的敏感性为97．2％，特异性为96．0％，阳性预测值为94．0％，阴性预测值为98．1％。经配对χ^2检验，P=0．052，证明两种检查方法在发现冠状动脉病变方面差异无统计学意义。在显示病变程度上，64SCTCA评估与CCA完全一致者311支，准确性86．8％。在64SCTCA结果中，共有59支病变在程度上的评价与CCA结果不符合。结论 64SCTCA在显示冠状动脉病变时，具有较高的敏感性和特异性，并且对于病变程度的评估也比较准确，适合用于临床怀疑冠心病的患者CCA前的筛选检查。     

64层螺旋CT评价冠状动脉支架内再狭窄的价值

目的 评价64层螺旋CT诊断冠状动脉支架内再狭窄（ISR）的临床价值。方法 采用64层螺旋CT对14例冠状动脉支架置入术后的患者（共37个支架）进行CT冠状动脉成像（CTA）。在CTA上，通过肉眼观察和测量支架内CT值两种方法诊断ISR。以冠状动脉造影（ISR≥50％）为标准，计算并比较两种方法诊断ISR的准确性。结果 37个支架中，CCA检出ISR（≥50％）11个，正常（包括ISR〈50％）26个。与CCA对照，CTA肉眼观察法正确诊断ISR2个，正常18个，CT值测量法则分别正确诊断ISR3个，正常21个。两种方法诊断ISR的敏感性、特异性、阳性预测值和阴性预测值分别为18％、69％、20％、67％和27％、81％、38％、72％。两种方法各项准确性指标之间差异均无缔计学意义（P〉0．05）。结论 64层螺旆CT诊断ISR十分困难．但对排除ISR有一定的作用。     

128层CT冠状动脉成像对左心室功能的评价

目的:应用冠状动脉成像原始数据,了解左心室形态变化,评价整体左心室功能。方法:收集90例患者冠状动脉成像原始数据,行MPR,观察左心室形态和各心肌节段的变化,并应用心功能分析软件自动计算出左心室收缩末期容积(ESV)、舒张末期容积(EDV)和射血分数(EF)。根据冠状动脉、左心室形态及整体左心室功能,将所有患者分为对照组、冠心病组、左心室肥厚组及心功能衰竭组,结合各组左心室形态变化,将左心室ESV、EDV和EF进行统计学比较和分析。结果:对照组患者冠状动脉和左心室形态正常;冠心病组左心室壁局限性增厚7例和变薄13例;左心室肥厚组左心室缩小、心室壁增厚;心功能衰竭组心室扩大、室壁普遍变薄。对照组、冠心病组、左心室肥厚组、心功能衰竭组平均EDV和ESV分别为(133.58±14.91)mL、(51.33±11.06)mL;(130.68±11.53)mL、(56.16±8.24)mL;(97.59±8.18)mL、(29.53±4.78)mL;(229.40±50.64)mL、(171.27±60.64)mL。冠心病组与对照组平均EDV和ESV比较,差异无统计学意义,左心室肥厚组及心功能衰竭组与对照组比较,差异均有统计学意义(P0.001)。对照组、冠心病组、左心室肥厚组、心功能衰竭组EF分别为(61.25±5.83)%、(56.37±6.79)%、(68.94±5.36)%和(26.33±8.30)%,差异均有统计学意义。结论:应用冠状动脉成像原始数据,结合冠状动脉及左心室形态改变,无创评价左心室整体功能,实用而可行,可为临床提供更多有价值的信息。     

64层螺旋CT在冠状动脉狭窄诊断中的应用价值

目的:探讨64层螺旋CT冠状动脉成像在冠状动脉狭窄诊断中的优势及临床应用价值。方法:选择2008年10月～2009年3月间收集可疑冠心病患者40例;所有患者行64层螺旋CT(MSCT)回顾性心电门控冠状动脉造影检查。扫描模式为常规冠状动脉检查模式;所有患者心率控制在45～70次/min之间。检查数据传输至AW4.3工作站,应用冠状动脉分析软件对图像进行处理;分析采用容积重建(VR)、最大密度投影(MIP)及曲面重建(CPR)等技术对冠状动脉进行分析、评价。结果:40例中冠状动脉狭窄37例,其中轻度狭窄18例(狭窄率<50%),中度狭窄14例(狭窄率50%～75%之间),重度狭窄乃至闭塞5例(狭窄率>75%),无狭窄3例。狭窄区斑块分别为软斑块、纤维斑块、钙化斑块及混合斑块,其中单一成分斑块14例,多种成分斑块同时存在23例。结论:64层螺旋CT在冠状动脉狭窄的诊断及临床应用上可作为一种可靠的检查手段,可替代传统X线冠状动脉造影检查,并作为冠心病、冠状动脉狭窄的筛查及诊断的首选检查方法。     

A 16-slice multidetector computed tomography protocol for evaluation of the gastroepiploic artery grafts in patients after coronary artery bypass surgery

Arterial coronary bypass grafts [internal mammary arteries and gastroepiploic artery (GEA)] are in widespread use for coronary surgery. Since selective catheterisation of the GEA graft to monitor patency, is often unsuccessful, a non-invasive protocol to visualise the GEA-graft from origin to anastomosis is presented using 16-slice multidetector computed tomography (MDCT). Twenty-six male patients (mean age 58.1±6.7 years) with GEA grafts were scanned according to a protocol of an ECG-synchronised cardiac scan followed by a thoracoabdominal scan. To terminate the scan at the correct anatomical level, the lowest level of the GEA was coded based on the lumbar vertebrae level. Scores ranging from one (excellent) to four (bad) were assigned to evaluate visualisation quality of the grafts. GEA grafts were assessable in 62% of the thoracoabdominal scans and 69% of the cardiac scans. On average, the lowest part of the GEA corresponded with a level between L1 and L2, in two cases in the upper part of L3. Mean visualisation score in the thoracoabdominal scans and cardiac scans was good (respectively 1.4±0.6 and 1.4±1.0). Sixteen-slice MDCT is a promising alternative for catheterisation in evaluating patency of GEA grafts, using the presented protocol with thoracoabdominal scan including L3 for complete coverage of the GEA graft.     

64层螺旋CT冠状动脉粥样硬化斑块稳定性分析

目的探讨64层螺旋CT冠状动脉成像在判别冠心病不同类型间斑块性质方面的价值。方法经冠状动脉造影(CAG)证实明确诊断为冠心病的患者126例,行64层螺旋CT冠状动脉成像,并对主要冠状动脉狭窄节段数、狭窄程度以及斑块性质进行比较。结果本组患者冠状动脉评估节段数368个,其中狭窄节段195个(35.4%)。狭窄<50%共98个节段,狭窄50%～75%共71个节段,狭窄>75%共26个节段(左前降支中段、近段、后降支中段、左回旋支近段),其中完全闭塞2个(右冠状动脉近段以远、左回旋支中段以远)。软斑块46个(27.3%),纤维斑块42个(31.5%),混合斑块78个(29.5%),钙化斑块93个(12.6%)。对应斑块测量的CT值分别为软斑块(17±26)HU,纤维斑块(97±35)HU,钙化斑块(489±195)HU。结论 64层螺旋CT冠状动脉成像有助于显示斑块性质。     

Assessment of coronary artery stent patency by electron-beam CT

Following coronary angioplasty and stent implantation, restenosis remains common and its outcome difficult to predict. We set out to determine the diagnostic accuracy of electron-beam computed tomography (EBCT) for the non-invasive detection of stent obstruction. In a prospective, blinded investigation, we included 152 coronary artery segments in 117 patients treated with a stent implant. All segments were evaluated by a dynamic EBCT study that depicted contrast bolus passage distal to the stent and a CT angiographic study of the entire coronary arteries. It was found that delayed contrast enhancement in the distal segment correlated with angiographic stent obstruction (Spearmans rank correlation, P=0.008), while all other indicators of stent occlusion did not correlate with angiographic diagnosis. However, direct comparison of patients with obstruction of less vs. more than 75% of luminal diameter did not yield any statistically significant differences of distal enhancement delay, and for the detection of >90% occlusion, the sensitivity was 72% at a specificity of 60%. Although delayed contrast enhancement distal to the stent upon EBCT did correlate with angiographical obstruction, the correlation did not suffice to appear clinically satisfactory.     

64层螺旋CT诊断先天性冠状动脉变异

目的:探讨多层螺旋CT(MSCT)在成年人先天性冠状动脉变异诊断中的临床应用价值。方法:回顾性分析726例成年人患者的冠状动脉MSCT造影资料,判断各种先天性冠状动脉变异。结果:726例MSCT冠状动脉造影中检出冠状动脉变异39例,包括冠状动脉开口起源异常11例,单支冠状动脉1例,冠状动脉瘤2例,冠状动脉分支起源异常11例,冠状动脉发育不良13例,冠脉开口处急性扭转走行异常1例。结论:MSCT是一种无创、准确、可重复性强的诊断先天性冠状动脉变异的重要手段。     

Detection of myocardial bridge and evaluation of its anatomical properties by coronary multislice spiral computed tomography

BACKGROUND: Myocardial bridge (MB) is a common anatomical condition, under which a part of the coronary artery running in the epicardial adipose tissue, is covered with myocardial tissue. It regulates atherosclerosis development and sometimes evokes coronary heart disease through haemodynamic alterations. We attempted to efficiently detect MB and evaluate the anatomical properties of MB by coronary multislice spiral computed tomography (MSCT). METHODS: Sixteen-row MSCT was conducted on 148 patients with coronary heart disease. MSCT images were reconstructed and reformed with transverse scans, curved planar reformat and three-dimensional volume-rendered images. The MB, over 1.0 mm in thickness, was identified by the presence of the "step-down and step-up" appearance. After "trial and error" essays, we could consistently examine the frequency of MB and evaluate the anatomical properties of MB, especially its thickness, together with coronary wall lesions. RESULTS: Twenty-three patients (15.8%) had MB over 1.0 mm in thickness: 21 MBs (87.5%) were located in the left anterior descending artery with a mean thickness and length of 1.8+/-0.7 and 20.0+/-8.6 mm. Moreover, although the tunneled segment beneath MB was always free of coronary wall lesions, 79.2% (19/24) of the segments proximal to MB demonstrated coronary wall lesions. Of special significance were three symptomatic MB patients without any atherosclerotic lesion throughout all the coronary arteries. CONCLUSION: Coronary MSCT is a new imaging technique that provides a non-invasive diagnostic tool for MB and yields much better results of MB detection than previous imaging methods.     

Assessment of coronary artery patency after stent placement using magnetic resonance angiography

The ability to noninvasively assess the patency of coronary stents would represent a significant advance. We evaluated the safety and ability of two-dimensional coronary MR angiography In imaging stents and suggesting patency. Coronary MR angiography of 26 coronary stents (Palmaz-Schatz) was performed in 16 patients 39 to 73 years of age. Studies were performed between 2 and 4 months after stent placement. All patients were symptom free at the time of imaging. Coronary MR angiography was performed with a commercial 1.5-T MR imager using an electrocardio-graphically gated pulse sequence with breath-holding. Images were obtained in mid-diastole with and without fat suppression. Image artifacts caused by the metal in the stents were clearly visualized in all 26 stents (100% sensitivity for stent detection). Arterial flow signal was seen in the coronary artery or graft distal to the stent in 25 of 26 cases (96%). All patients, except for the one in which distal flow could not be seen, remained symptom free for >2 years. The distribution of stent locations was as follows: 10 in the right coronary artery (RCA), 10 in the left anterior descending coronary artery (LAD), 2 in the left circumflex coronary artery, and 4 in saphenous vein grafts (SVGs) to RCA. One patient had 2 RCA and 2 LAD stents, one had 3 RCA and 1 LAD stents, one had 3 SVG stents, and two had double RCA stents. Coronary MR angiography is safe for noninvasive imaging of coronary stents, and in the proper clinical setting, it can be used to help suggest patency.     

64层螺旋CT检测不同程度冠状动脉狭窄临床分析

目的：探索64层螺旋CT对冠脉管腔的可评价率和诊断不同程度冠脉狭窄的敏感性、特异性、阳性预测值和阴性预测值并进行比较。方法：将我院2006年1月～2008年7月经选择性冠状动脉造影（selective coronary angiography,SCA）对比的127例64层螺旋CT检测的冠脉狭窄患者的资料进行整理、统计、分析和对比。结果：冠脉管腔可评价率为95.6%。轻、中、重度冠脉狭窄的敏感性为85.9%、90.3%、95.3%（P〈0.05）;特异性为98.3%、99.0%、99.5%（P〈0.05）;阳性预测值为87.8%、91.6%、93.5%（P〉0.05）;阴性预测值为98.0%、99.0%、99.7%（P〈0.001）。结论：64层CT对冠脉管腔的可评价率高,对诊断轻、中、重度冠脉狭窄的敏感性、特异性、阳性预测值、阴性预测值均较高,且各百分率有随冠脉狭窄程度的增加而逐渐增高的趋势,并且发现排除性指标优于诊断性指标。     

64层螺旋CT冠状动脉成像临床应用

目的：探讨64层螺旋CT（MSCT）冠状动脉成像方法显示冠状动脉狭窄的能力及可靠性。方法：对26例临床怀疑冠心病的患者行心脏冠状动脉CT成像（CTA）并与常规冠状动脉造影（CAG）结果进行比较分析。结果：以冠状动脉血管造影（CAG）为金标准,冠状动脉CTA影像判断血流动力学相关性冠状动脉狭窄（≥50%）的敏感度0.933、特异度0.974、准确度0.968、阳性预测值0.857、阴性预测值0.989。结论：64层螺旋CT冠状动脉成像是一种无创、简便、优良的冠状动脉成像方法,可作为冠状动脉粥样硬化的筛选手段及冠状动脉术后复查的首选方法。     

The use of computed tomography in the diagnosis of coronary artery bypass graft patency

In a preliminary evaluation of the use of dynamic computed tomography (CT) for the detection of patent aortocoronary bypass grafts, 30 patients were scanned either during the early postoperative peroid or after graft patency was determined by angiography. To visualize the proximal grafts, CT scans were taken through the aortic root following an intravenous bolus injection of contrast medium. Patent bypass grafts to the left anterior descending and right coronary arteries were demonstrated in 77.5%, while posterior grafts to the circumflex and obtuse marginal coronary arteries were detected in 40%. With its pontential for extracting dynamic events, CT scanning provides a new, noninvasive modality for the diagnosis of patent bypass grafts, which heretofore have only been visualized by selective angiography.