Assessment of coronary artery stent restenosis by 64-slice multi-detector computed tomography.

AIMS: We investigated the feasibility of assessing coronary artery stent restenosis using a new generation 64-slice multi-detector computed tomography-scanner (MDCT) in comparison to conventional quantitative angiography. METHODS AND RESULTS: MDCT was performed in 64 consecutive patients (mean age 58+/-10 years) with previously implanted coronary artery stents (102 stented lesions: mean stent diameter 3.17+/-0.38 mm). Each stent was classified as 'evaluable' or 'unevaluable', and in evaluable stents, the presence of in-stent restenosis (diameter reduction >50%) was determined visually. Results were verified against invasive, quantitative coronary angiography. Fifty-nine stented lesions (58%) were classified as evaluable in MDCT. The mean diameter of evaluable stents was 3.28+/-0.40 mm, whereas the mean diameter of non-evaluable stents was 3.03+/-0.31 mm (P=0.0002). Overall, six of 12 in-stent restenoses were correctly detected by MDCT [50% sensitivity (confidence interval 22-77%)] and in 51 of 90 lesions, in-stent restenosis was correctly ruled out [57% specificity (46-67%)]. In evaluable stents, six of seven in-stent restenoses were correctly detected, and the absence of in-stent stenosis was correctly identified in 51 of 52 cases [sensitivity 86% (42-99%) and specificity 98% (88-100%)]. CONCLUSION: Stent type and diameter influence evaluability concerning in-stent restenosis by MDCT. The rate of assessable stents is low, but in evaluable stents, accuracy for detection of in-stent restenosis can be high.     

Usefulness of 64-slice multislice computed tomography coronary angiography to assess in-stent restenosis.

OBJECTIVES: This study sought to evaluate the diagnostic accuracy of 64-slice multislice computed tomography (MSCT) coronary angiography in the follow-up of patients with previous coronary stent implantation. BACKGROUND: Recent investigations have shown increased image quality and diagnostic accuracy for noninvasive coronary angiography with 64-slice MSCT as compared with previous-generation MSCT scanners, but data on the evaluation of coronary stents are scarce. METHODS: In 182 patients (152 [84%] male, ages 58 +/- 11 years) with previous stent (> or =2.5 mm diameter) implantation (n = 192), 64-slice MSCT angiography using either a Sensation 64 (Siemens, Forchheim, Germany) or Aquilion 64 (Toshiba, Otawara, Japan) was performed. At each center, coronary stents were evaluated by 2 experienced observers and evaluated for the presence of significant (> or =50%) in-stent restenosis. Quantitative coronary angiography served as the standard of reference. RESULTS: A total of 14 (7.3%) stented segments were excluded because of poor image quality. In the interpretable stents, 20 of the 178 (11.2%) evaluated stents were significantly diseased, of which 19 were correctly detected by 64-slice MSCT. Accordingly, sensitivity, specificity, and positive and negative predictive value to identify in-stent restenosis in interpretable stents were 95.0% (95% confidence interval [CI] 85% to 100%), 93.0% (95% CI 90% to 97%), 63.3% (95% CI 46% to 81%), and 99.3% (95% CI 98% to 100%), respectively. CONCLUSIONS: In-stent restenosis can be evaluated with 64-slice MSCT with good diagnostic accuracy. In particular, a high negative predictive value of 99% was observed, indicating that 64-slice MSCT may be most valuable as a noninvasive method of excluding in-stent restenosis.     

New diagnostic technique in multi-slice computed tomography for in-stent restenosis: pixel count method

OBJECTIVES: A diagnostic technique to objectively determine coronary in-stent stenosis was developed with multi(16)-slice computed tomography (MSCT), and it was compared with coronary angiography (CAG) in clinical cases. BACKGROUND: MSCT is expected to replace coronary angiography as a new non-invasive examination. Evaluation of highly calcified or in-stent lesions with CT is generally thought to be difficult. METHODS: Twenty lesions among 16 consecutive patients that were implanted with coronary stents were examined with both MSCT and CAG at follow-up. The minor axis cross sections of the stents were reconstructed at intervals of 1.5 mm with multiplanar reformation (MPR). The pixel with a higher CT value than the lowest CT value in the standard cross section at the proximal site out of stent was counted to determine the presence/absence of a stenotic lesion. RESULTS: Among 20 lesions, one case was not able to be evaluated with MSCT. MSCT correctly detected 3 of 4 cases with in-stent stenosis (sensitivity 75%), and 14 of 16 cases with no in-stent stenosis (specificity 88%, negative predictive value 93%, positive predictive value 75%). If analysis was made per-artery, sensitivity and specificity were 100% (3 of 3) and 87% (13 of 15), respectively, for detection of in-stent stenosis. CONCLUSIONS: This study was performed to examine a unique diagnostic technique: pixel count method, for coronary in-stent stenosis with MSCT. It showed that the coronary in-stent stenosis could be determined when stent struts were clearly imaged. Further examination is required with various stents, especially those with a diameter of 3.0 mm or smaller.     

双源CT对冠状动脉支架靶血管再狭窄的诊断价值

目的:探讨双源CT（DSCT）对冠状动脉支架置入靶血管再狭窄的诊断价值。方法:对我院69例冠状动脉支架置入患者（共111枚支架）进行DSCT,评价支架图像质量得分与靶血管级别的相关性;并对部分患者同期进行冠状动脉造影（CAG）检查,对比分析DSCT对冠状动脉支架置入靶血管病变的真实性。结果:DSCT支架图像质量得分与靶血管级别正相关;DSCT对支架靶血管再狭窄诊断的灵敏度82%、特异度98%、和准确度95%;DSCT与CAG对不同直径支架的靶血管再狭窄检出率差异无统计学意义,但DSCT对直径≥3.0 mm支架靶血管再狭窄检出的特异度和准确度明显高于直径＜3.0 mm支架靶血管的相应指标（均P＜0.05）,而灵敏度的差异未达到显著水平。结论:DSCT可清晰的显示冠状动脉支架靶血管的病变情况,能较准确地评价冠状动脉支架靶血管再狭窄的发生,具有临床应用价值。     

MSCT冠状动脉成像在冠状动脉支架置入术后的应用

目的 探讨64排螺旋CT （MSCT）冠状动脉成像在冠状动脉支架置入后的应用价值.方法 分析行冠状动脉支架置入术后于我院2011年9月至2013年8月期间行64排MSCT冠状动脉成像的患者47例.用评分的方法客观评估多层螺旋CT血管造影（MSCTA）对冠状动脉支架的显示情况,并对支架管腔狭窄情况进行评估测量.对于中重度狭窄的患者进一步行DSA检查,并分析其与MSCTA评估结果的相关性.结果 47例患者共置入89枚冠状动脉支架,其中评为3分的支架为39枚,评为2分的支架为41枚,评为1分的支架为9枚.39枚支架没有发现狭窄,24枚支架轻度狭窄,15枚支架中度狭窄,11枚支架重度狭窄.DSA与MSCTA对中、重度狭窄的评估呈高度正相关,相关系数为r=0.804.伴钙化支架组MSCTA中、重度狭窄评估结果与DSA评估结果呈中度相关,相关系数为r=0.603.结论 MSCT冠状动脉成像能够很好地显示冠状动脉支架及其管腔狭窄,具有重要的临床价值.支架局部的钙化是影响评估准确性的因素之一.     

Usefulness of 16-slice multislice spiral computed tomography for follow-up study of coronary stent implantation.

BACKGROUND: Although multislice spiral computed tomography (MSCT) is a promising technique for non-invasive coronary angiography, its usefulness in patients with stent implantation remains unclear. The aim of the present study was to compare the usefulness of MSCT with that of invasive coronary angiography for evaluating coronary stent patency. METHODS AND RESULTS: Thirty-one patients were enrolled after coronary stent implantation. Sixteen-slice MSCT scans were performed (39.0+/-21.8 days) before follow-up coronary angiography. After assigning an image score based on luminal visibility (1= poor, 2= fair, 3= good), factors determing image quality were analyzed. Among 42 implanted stents, 33 (78%) were assigned an image score of 3, 2 (5%) a score of 2, and 7 (17%) a score of 1. Image scores among stents with diameters >or=3.5 mm were significantly (p<0.05) higher than among smaller stents (相似文献   

双源CT在冠状动脉支架内再狭窄诊断中的价值

目的 参照定量冠状动脉造影结果,评价双源CT在冠状动脉支架内再狭窄诊断中的价值.方法 对55例支架术后出现胸闷、胸痛的冠心病患者,在术后6～12个月行双源CT检查及定量冠状动脉造影.以定量冠状动脉造影结果为参照,评价双源CT诊断支架内再狭窄的真阳性、真阴性、假阳性、假阴性,并计算敏感性、特异性、阳性预测值、阴性预测值.分析心率、置人支架情况对双源CT诊断性能的影响.结果 55例患者共置入89枚支架,其中31.5%(28/89)的支架经冠状动脉造影证实发生支架内再狭窄.双源CT诊断支架内再狭窄的敏感性、特异性、阳性预测值、阴性预测值分别为89%、87%、76%和95%.双源CT诊断心率＜70次/min及≥70次/min患者支架内再狭窄的敏感性(94%比82%)、特异性(88%比90%)、阳性预测值(76%比75%)、阴性预测值(97%比93%)差异无统计学意义(P＞0.05).双源CT诊断重叠支架、分叉部位支架与单支架再狭窄的敏感性(84%比100%)、特异性(81%比96%)、阳性预测值(70%比90%)和阴性预测值(91%比100%)差异无统计学意义(P＞0.05).双源CT诊断直径≥3.50 mm支架、直径3.00 mm支架和直径≤2.75mm支架发生再狭窄的特异性(分别为100%、80%和66%,P＜0.05)和阳性预测值(分别为100%、95%和53%,P＜0.05)差异有统计学意义.结论 双源CT对大直径支架的再狭窄有较好的诊断性能,且不受心率和支架分布情况的影响.

Abstract：

Objective To evaluate the value of dual source computed tomography coronary angiography(DSCT-CA)on detecting in-stent restenosis(＞ 50% luminal narrowing)in symptomatic patients referred for quantitative coronary angiography(QAC). Methods Fifty five patients(43 males)with chest pain after coronary stent implantation within 6 - 12 months were evaluated by DSCT-CA and QAC. The sensitivity, specificity, positive predictive value(PPV)and negative predictive value(NPV)of DSCT-CA were calculated using coronary angiography as gold standard. Results Eighty nine stents were implanted.In-stent restenosis was evidenced in 28 stents(31.5%)by QAC. The sensitivity, specificity PPV and NPV of DSCT-CA for the diagnosis of in-stent restenosis was 89%, 87%, 76% and 95%, respectively.Diagnostic efficiency was not affected by heart rate and the sensitivity was 0. 94 vs. 0.82, the specificity 0. 88 vs. 0. 90, the PPV 0. 76 vs. 0.75 and the NPV 0. 97 vs. 0. 93(all P ＞ 0. 05)between patients with heart rate ＜70 beats/min and patients with heart rate≥70 beats/min. The sensitivity(84% vs. 100%),specificity(81% vs. 96%), PPV(70% vs. 90%)and NPV(91% vs. 100%)were similar between overlapping or bifurcations stents and single stents. The specificity(100% vs. 80% vs. 66%)and PPV (100% vs. 95% vs. 53%)were significantly higher in the groups with stents ≥3.50 mm, stents 3.00 mm than in stents ≤2. 75 mm(both P ＜ 0. 05). Conclusion Diagnostic efficiency of in-stent restenosis with DSCT-CA in the large diameter stent is better than in the small diameter stent and the diagnosis efficacy is not affected by heart rate and stent distribution.     

64层螺旋CT冠状动脉成像在冠状动脉支架置入术后随访中的价值研究

目的以冠状动脉造影为金标准,评价64层螺旋CT冠状动脉成像（64SCTCA）在冠状动脉支架术后随访中的临床价值。方法对33例支架术后患者共57个支架行CT冠状动脉成像,观察冠状动脉支架处是否再狭窄并与冠状动脉造影（CAG）结果对照。结果 64SCTCA检查显示57个支架部位再狭窄8处,与CAG相比误判3处,漏判一处,但两者差别无统计学意义。其敏感度和特异度分别达到了83.3%和94.1%。结论 64SCTCA能够较准确判断冠状动脉支架术后是否发生了再狭窄,可作为支架术后随访的重要手段。     

Accuracy of multislice computed tomography coronary angiography: a pooled estimate

A PUBMED search was performed for peer-reviewed studies published in English from 2002 through August 2006. Accuracy parameters for detection of obstructive coronary artery disease by MSCT (multislice computed tomography) coronary angiography were analyzed on patient and segment basis. Pooled estimates of sensitivity (SN), specificity, positive predictive value, and negative predictive value (NPV) in patient-based analyses were 93%, 82%, 83%, and 92%, respectively. For 64/40-slice MSCT the respective accuracy estimates were 96%, 91%, 93%, and 96% and were better compared with 16-slice MSCT. Also, more segments were evaluated by 64-slice MSCT (96%) compared with 16-slice MSCT (86%). The SN and NPV of MSCT coronary angiography for patients with low coronary artery calcium (CAC) score were 92% and 99% compared with 77% and 89% for patients with high CAC score. The accuracy estimates for MSCT in studying coronary artery by-pass grafts and intracoronary stents showed a SN and NPV of 97% and 97% for graft occlusion or stenosis and only 71% and 93% respectively for in-stent restenosis. Diagnostic accuracy of MSCT coronary angiography has improved with the newer 64-slice versions. High CAC scores can affect the accuracy of MSCT coronary angiography. Although the accuracy of MSCT in evaluating native vessel and graft disease has improved significantly, its reliability in studying intracoronary stents remains uncertain.     

Noninvasive assessment of coronary stents in patients by 16-slice computed tomography

BACKGROUND: The usefulness of thin-slice multi-detector computed tomography (MDCT) has been highly expected to assess the lumens of coronary artery stents. We evaluated the usefulness of 16-slice MDCT to assess the in-stent lumen after coronary artery stenting. METHODS: In 42 consecutive patients after coronary artery stenting, retrospective ECG-gated CT-angiography using 16-slice MDCT (0.5-s rotation time, 16x0.625-mm detector collimation) was performed. The qualitative assessability of the lumens of 61 coronary stents (14 different types) by MDCT and the reasons for non-assessability were investigated. Furthermore, the evaluation of in-stent restenosis in 21 assessable stents of 16 patients, including quantitative density analysis by MDCT, was performed and the results were compared with those of conventional coronary angiography (CAG). RESULTS: Of 61 stents, 42 (68.9%) were assessable. The assessability of diameter > or =3.5-mm stents made of stainless steel or cobalt was high (88.6%, 31/35), that of 3.0-mm stents was low (57.9%, 11/19) and all 2.5-mm stents were non-assessable due to partial volume effects and metal artifacts of stents. The lumens of stents made of tantalum were totally obscured and the metal artifacts of Bestent2 (gold markers) and S670 were severer than others. All non-assessable stents due to banding artifact and calcification were implanted in segment #1-3 and #6, respectively. In comparison to CAG, MDCT correctly detected the 5 in-stent restenoses and identified absence of restenoses was influenced strongly by the stent strut. CONCLUSION: Despite some limitations, 16-slice MSCT is sufficiently useful for assessment of various coronary stents in patients and can detect in-stent restenoses of assessable stents with high accuracy in comparison to CAG.     

Noninvasive coronary imaging and assessment of left ventricular function using 16-slice computed tomography

In recent years, multislice computed tomography (MSCT) has been demonstrated to be a feasible imaging modality for noninvasive coronary angiography and left ventricular function analysis. The present study evaluated overall performance of 16-slice MSCT in the detection of significant coronary artery disease, stent, or bypass graft stenosis in combination with global left ventricular function analysis. Forty-five patients underwent 16-slice MSCT. Multislice computed tomograms were used to evaluate the presence of significant coronary artery stenoses (>/=50% decrease in luminal diameter) in native coronary segments, bypass grafts, and coronary stents and were compared with conventional coronary angiograms. In addition, left ventricular ejection fraction was calculated and compared with 2-dimensional echocardiography. MSCT was performed successfully in all patients. A close correlation between MSCT and 2-dimensional echocardiography was demonstrated for the assessment of left ventricular ejection fraction (y = 0.93x +3.33, r = 0.96, p <0.001). A total of 298 of native coronary artery segments (94%) were evaluated with MSCT, whereas 81 of 94 grafts (85%) and 41 of 52 coronary stents (79%) were also evaluated. For all segments, overall sensitivity, specificity, and positive and negative predictive values were 85%, 89%, 71%, and 95%, respectively. In conclusion, 16-slice MSCT is a feasible modality for noninvasive evaluation and exclusion of coronary artery disease in patients who present with chest pain.     

64排螺旋CT在冠脉支架植入术后随访中的应用

目的 探讨64排螺旋CT血管成像技术在冠脉支架植入术后随访中的应用价值.方法 18例支架植入术后患者,术后3～20个月接受64排螺旋CT检查,多层螺旋CT增强扫描结合回顾性心电门控技术.患者同时接受选择性冠状动脉造影.结果 64排螺旋CT血管成像的检查结果显示,18例患者接受植入的28个支架中,22个支架通畅,3个支架完全闭塞,与选择性冠状动脉造影结果相一致;另外3个支架因为伪影的影响不能被评价.结论 64排螺旋CT是评价支架通畅与否的一项新的很有价值的无创方法.     

320排CT冠状动脉血管成像与冠状动脉造影评估冠状动脉支架内再狭窄程度的对比分析

目的评价320排CT冠状动脉血管成像(CCTA)在冠状动脉支架内再狭窄评估中的临床应用价值。方法以选择性冠状动脉造影(CAG)为金标准,应用320排CCTA评价100例患者冠状动脉支架内再狭窄的程度。将冠状动脉支架内管径分为无狭窄、轻度狭窄(≤50%)、中度狭窄(51%～75%)和重度狭窄或闭塞(76%～100%)4个等级,分析320排CCTA与CAG评估狭窄程度的一致性。其中再狭窄≥50%为阳性,包括支架内及支架两端5mm范围内的血管段。统计学方法采用Kappa评价方法。结果 100例患者中共评价分析175枚支架,CAG示冠状动脉支架内再狭窄44枚,320排CCTA正确诊断42枚,漏诊2枚,误诊10枚,敏感度为95.45%、特异度为92.37%、准确度为70.29%、阳性预测值为80.77%、阴性预测值为98.37%。在P<0.05的检验标准上,Kappa值为0.5688,320排CCTA和CAG对支架内狭窄程度评估一致性好。结论 320排CCTA能够准确显示支架内再狭窄的部位及程度,而且无创、重复性好,图像直观可信,具有很高的临床应用价值。     

In vitro evaluation of metallic coronary artery stents with sub-millimeter multi-slice computed tomography using an ECG-gated cardiac phantom: relationship between in-stent visualization and stent type

The aim of this experimental study was to investigate visualization of various coronary artery stents with sub-millimeter multi-slice spiral computed tomography (MSCT) using a cardiac physical phantom. Four 3-mm stents of various designs were implanted in tubes with an inner diameter of 3 mm to simulate coronary artery. Stents were placed on a cardiac phantom and scanned at different heart rates. Retrospective ECG-gated adaptive segmental reconstruction technique was employed. Profile curves across longitudinal curved planar reconstruction images of the stents were generated. From the profile curve, the full width at half maximum was defined as the stent lumen index. The effect of heart rate and stent type on the stent lumen index was evaluated. Visual evaluation for each stent at various heart rates was also performed. The heart rate had no significant effect on in-stent visualization. However, in-stent visualization differed significantly for the various stent types for both profile curve analysis and visual evaluation (the Tukey-Kramer multiple comparisons test). Multiple regression analysis indicated that strut thickness, especially minimal strut thickness, was the significant influencing factor for the in-stent visualization. On the basis of four stent models examined it would appear that visualization of the coronary stent lumen varies depending on the stent type, but not on the heart rate. Stents with slim struts are preferable for in-stent evaluation with multi-slice spiral computed tomography.     

Non-invasive computed tomography angiography in the assessment of coronary stent patency: an Australian experience

Background: This study aimed to evaluate the feasibility and accuracy of 16‐slice computed tomography (CT) in the assessment of coronary stent patency. CT coronary angiography (CA) has a high degree of accuracy in the assessment of coronary artery disease compared with invasive selective CA. However, its accuracy in the evaluation of stent patency is not well investigated. Methods: We conducted a retrospective observational study of paired CT coronary angiography (CT–CA) and invasive fluoroscopic coronary angiography (FCA) in 37 patients with 47 coronary stents. CT–CA was carried out with an electrocardiogram‐gated 16‐slice CT (LightSpeed‐16, General Electric (GE), WI, USA). Two CT reporters, blinded to the FCA findings, assessed CT images for stent patency. A cardiologist blinded to CT findings reported FCA. FCA was regarded as the reference standard. Results: A CT–CA could assess 45 of 47 coronary stents (96%). Non‐assessable stents on CT–CA were due to motion artefacts and stent‐blooming effects. Of those 45 assessable stents, CT–CA correctly identified five out of seven stents with binary in‐stent restenosis (ISR) and 37 of 38 stents without binary ISR. The sensitivity and specificity of 16‐slice CT in the evaluation of coronary stents for binary ISR were 71% (95% confidence interval (CI) (29%, 96%)) and 97% (95%CI (86%, 100%)), respectively, exclusive of non‐assessable stents. The positive and negative predictive values of 16‐slice CT were 83% (95%CI (36%, 100%)) and 95% (95%CI (83%, 99%)), respectively. Conclusion: Sixteen‐slice CT has a low sensitivity, but very a high specificity when compared with FCA in the evaluation of coronary stents for ISR.     

高密度脂蛋白与冠状动脉支架植入术后再狭窄的关系

目的探讨再次入院造影复查时血高密度脂蛋白胆固醇水平与冠状动脉支架植入术后再狭窄的关系。方法根据再次冠状动脉造影复查结果,将370例行冠状动脉内支架术并随访造影结果的患者分为再狭窄组与非再狭窄组,对两组临床情况及生物化学指标进行回顾性分析。结果370例患者中有487支靶血管置入支架,94例患者的123支靶血管发生再狭窄。单因素分析显示再狭窄组的高密度脂蛋白胆固醇水平显著低于非再狭窄组,差异有显著性(P<0.05);二分类多因素Logistic回归分析显示低高密度脂蛋白胆固醇水平(高密度脂蛋白胆固醇≤1.04mmol/L)为冠状动脉内再狭窄的独立危险因素。结论提示血高密度脂蛋白胆固醇水平与冠状动脉支架植入术后再狭窄密切相关。     

Comparison of clinical and angiographic outcomes between S670 and NIR stents

OBJECTIVES: This study evaluated the long-term outcomes of successfully implanted S670 and NIR stents. METHODS: Stents were successfully implanted in 143 patients (148 lesions) aged 65 +/- 9 years from January 1999 to April 2001. Sixty-eight lesions were treated with S670 stents and 80 with NIR stents. Quantitative coronary angiography was performed before, immediately after and 6 months after implantation. An angiographic classification of in-stent restenosis was developed according to the geographic distribution of intimal hyperplasia in reference to the implanted stent. Furthermore, the relationships between stent diameter and length and restenosis rate were estimated. RESULTS: Type B2/C lesions were significantly more common in patients with S 670 (77.3%) stents compared with NIR (43.6%). Stent length was longer and diameter was smaller in patients with S 670 stents compared with those with NIR stents. Acute-gain was similar in the two groups, but late-loss was significantly greater in patients with S 670 stents compared with those with NIR stents. Restenosis rate and target lesion revascularization rate were similar in the two groups. The diffuse type of restenosis lesion was frequently found in S 670 stents. The stent diameter, but not stent length, influenced the restenosis rate in S 670 stents. Both stent length and diameter influenced the restenosis rate in NIR stents. CONCLUSIONS: Late-loss was larger and in-stent restenosis of diffuse type was significantly greater in S 670 stents compared with NIR stents. However, stent length was significantly longer and type B2/C lesions were significantly greater in S 670 stents compared with NIR stents. There was no difference in restenosis rate and target lesion revascularization rate. In addition, restenosis rate was not influenced by stent length in S 670 stents, so S 670 stents may be useful for complex lesions.     

Quantitative assessment of in-stent dimensions: a comparison of 64 and 16 detector multislice computed tomography to intravascular ultrasound.

OBJECTIVES: To determine the utility of multislice computed tomography (MSCT) technology to evaluate coronary stent luminal diameter. BACKGROUND: Stent metal induced "blooming" artifact makes quantitative coronary angiography by MSCT difficult. There is a paucity of data on the efficacy of using 64 and 16 detector MSCT in evaluating coronary stents. METHODS: We evaluated four commercially available bare metal and polymer coated drug eluting stents using 64 and 16 detector MSCT for the following: (1) Strut density in Hounsfield's Units (Hu) using a 2 mm MIP; (2) In-stent luminal diameter (ISLD) measured by MSCT compared to intravascular ultrasound (IVUS). RESULTS: Increased strut thickness did not correlate with greater strut density as measured in Hu (R(2) = 0.05, P = 0.29). The ISLD by 16 MSCT vs. IVUS is: Vision 1.63 +/- 0.58 mm vs. 2.8 +/- 0.0; Cypher 1.80 +/- 0.00 vs. 2.9 +/- 0.0; Taxus 1.87 +/- 0.58 vs. 2.9 +/- 0.0; Liberté 1.80 +/- 0.10 vs. 3.0 +/- 0.1 (P < 0.01). ISLD determined by 64 MSCT vs. IVUS is: Vision 1.73 +/- 0.06 mm vs. 2.8 +/- 0.0; Cypher 1.87 +/- 0.12 vs. 2.9 +/- 0.0; Taxus 1.77 +/- 0.06 vs. 2.9 +/- 0.0; Liberté 1.80 +/- 0.10 vs. 3.0 +/- 0.1 (P < 0.01). CONCLUSIONS: When compared to IVUS measurements, MSCT results in a significant, underestimation of ISLD. This consistent underestimation (even with 64 MSCT) limits the applicability of CT angiography to quantify in-stent restenosis.     

128层螺旋CT冠状动脉成像与选择性冠状动脉造影诊断冠心病价值的比较

目的 评价128层螺旋CT(MSCT)冠状动脉成像诊断冠状动脉疾病的价值.方法 对临床怀疑或确诊冠心病的非选择性连续78例患者进行128层MSCT冠状动脉成像,其中有15例患者既往置入冠状动脉支架.以选择性冠状动脉造影结果作为评价标准,探讨128层MSCT在诊断冠状动脉疾病及评价支架后再狭窄的临床价值.结果 基于冠状动脉血管节段分析,879个冠状动脉节段中有821节段(93%)进入统计学分析,128层MSCT诊断冠状动脉病变的敏感性87%,特异性97%,阳性预测值83%,阴性预测值97%.对15例共置入22个支架的患者中,有4个(18%)支架MSCT图像显示支架伪影,图像模糊,未能判断支架内血管腔通畅情况,其余18个支架MSCT结果与选择性冠状动脉造影比较,MSCT诊断支架再狭窄的敏感性为100%,特异性77%,阳性预测值63%,阴性预测值100%.结论 128层MSCT冠状动脉成像对冠状动脉疾病的诊断和支架再狭窄的评价具有较高价值,可以作为一项无创检查技术用于对临床怀疑为冠心病的患者进行筛查.     

Computed tomography coronary angiography.

Recent developments in computed tomography technology have made imaging of the coronary arteries possible. All the same, the rapid motion and small dimensions of the coronary vessels make coronary computed tomography angiography (coronary CTA) challenging. With the last generations of 16- and 64-slice computed tomography and adequate patient preparation (which includes lowering of the heart rate), rates of sensitivity ranging from 83% to 99% and specificity between 93% and 98% have been reported for the detection of coronary artery stenoses in comparison with invasive coronary angiography. The high negative predictive value (95% to 100%) found in these studies suggests that coronary CTA may be a useful diagnostic technique to rule out the presence of coronary stenoses in selected patients, especially those with a rather low pretest likelihood of disease. Imaging of coronary artery bypass grafts is reliable, but clinical applications can be hampered by difficulties in assessing the native coronary arteries in patients after undergoing bypass because of their often-severe calcification. The detection of in-stent restenosis is made difficult by artifacts caused by metal, especially in smaller stents. Finally, initial reports that coronary CTA allows the detection and, to a certain extent, also the characterization and quantification of noncalcified coronary arteriosclerotic plaque are interesting, but they currently do not provide sufficient data to support clinical applications in the context of risk stratification.