Multidetector-row cardiac CT: diagnostic value of calcium scoring and CT coronary angiography in patients with symptomatic,but atypical,chest pain

The aim of this study was to investigate the accuracy of multidetector-row cardiac CT (MDCT), calcium scoring (Ca-Sc), and MDCT coronary angiography (MD CTA) in the assessment of coronary atherosclerosis. Thirty-eight patients underwent invasive coronary angiography (CA) and MDCT (collimation 4×1 mm, pitch 1.5 mm, TI 500 ms, 120 kV, 300 mAs, and retrospective ECG-gating). Calcium scoring was calculated for the total coronary artery territory and for RCA, LCA, and LCX separately. The MD CTA served to assess the degree and the localization of stenoses. All findings were compared to invasive coronary angiography. Approximately 68.4% (390 of 570) of all coronary segments could be visualized by MDCT. Correlation coefficient for MD CTA and CA amounted to r=0.58, showing distinct differences for the individual segments. Proximal segments generally showed better correlation (range 0.81–0.77) than medial segments (range 0.91–0.20), distal segments (range 0.55–0.04), or side branches (range 0.76–0.00). Patients with hemodynamically relevant (>75%) stenoses were detected by MD CTA with 72.2% sensitivity (13 of 18) and 100% specificity (20 of 20). For Ca-Sc sensitivity ranged between 94.7% (17 of 18) and 66.7% (12 of 18), specificity between 20% (4 of 20) and 80% (16 of 20) respectively, depending on the prevailing cutoff value. Combination of both methods led to 83.3% sensitivity (15 of 18) and 100% specificity (20 of 20), reaching no level of significance as compared with Ca-Sc (p=0.73) or MD CTA (p=0.23) alone. Calcium scoring as a single method showed highest sensitivity in the detection of coronary atherosclerosis but at the expense of low specificity. In patients with no or moderate calcifications, combination with MD CTA helped to distinctly increase specificity and NPVM. Britten and C. Herzog contributed equally to this study     

The Diagnostic Accuracy, Image Quality and Radiation Dose of 64-Slice Dual-Source CT in Daily Practice: a Single Institution's Experience

Objective

We wanted to evaluate the image quality, diagnostic accuracy and radiation exposure of 64-slice dual-source CT (DSCT) coronary angiography according to the heart rate in symptomatic patients during daily clinical practice.

Materials and Methods

We performed a retrospective search for the DSCT coronary angiography reports of 729 consecutive symptomatic patients. For the 131 patients who underwent invasive coronary angiography, the image quality, the diagnostic performance (sensitivity, specificity, positive predictive value [PPV] and negative predictive value [NPV] for detecting significant stenosis ≥ 50% diameter) and the radiation exposure were evaluated. These values were compared between the groups with differing heart rates (HR): mean HR < 65 or ≥ 65 and HR variability (HRV) < 15 or ≥ 15.

Results

Among the 729 patients, the CT reports showed no stenosis or insignificant coronary artery stenosis in 72%, significant stenosis in 26% and non-diagnostic in 2%. For the 131 patients who underwent invasive coronary angiography, 95% of the patients and 97% of the segments were evaluable, and the overall per-patient/per-segment sensitivity, the perpatient/per-segment specificity, the per-patient/per-segment PPV and the per-patient/per-segment NPV were 100%/90%, 71%/98%, 95%/88% and 100%/97%, respectively. The image quality was better in the HR < 65 group than in the HR ≥ 65 group (p = 0.001), but there was no difference in diagnostic performance between the two groups. The mean effective radiation doses were lower in the HR < 65 or HRV < 15 group (p < 0.0001): 5.5 versus 6.7 mSv for the mean HR groups and 5.3 versus 9.3 mSv for the HRV groups.

Conclusion

Dual-source CT coronary angiography is a highly accurate modality in the clinical setting. Better image quality and a significant radiation reduction are being rendered in the lower HR group.     

16层螺旋CT冠状动脉成像的伪影缺陷及处理对策

目的：探讨16层螺旋CT冠状动脉成像伪影和技术缺陷产生的原因与解决对策。方法：122例临床疑似或已确诊为冠心病的患者,以回顾性心电门控技术行16层螺旋CT冠状动脉成像检查,后处理行MIP、CPR、MPR及VR重建,由两名以上有经验的CT医师对冠状动脉成像的缺陷或伪影进行评估。结果：122例患者共显示冠状动脉节段1496段,存在伪影326段,占21．79％,大部分为轻度伪影275段（18．38％）,中重度伪影51段（3．41％）。结论：冠状动脉CTA的伪影和缺陷原因如下：心脏运动、呼吸运动、射线硬化、对比剂、重建时相、扫描和后处理技术等。认识并尽力排除这些伪影和技术缺陷,才能做出正确诊断。     

钙化积分、CTCA以及两者联合对冠状动脉狭窄的诊断价值

目的:探讨冠状动脉钙化积分(CS)、CT冠状动脉成像(CTCA)以及两者联合对诊断冠状动脉狭窄病变的价值.方法:189例患者均行冠状动脉钙化积分扫描、CT冠状动脉成像以及传统冠状动脉造影(CAG)检查.计算CS、CT-CA以及两者联合诊断冠状动脉病变的符合率,并记录有效X线剂量.结果:189例患者中临床诊断为冠心病156例(82.5％),经冠状动脉造影检测出至少有1支冠状动脉狭窄≥50％.采用钙化积分250分作为诊断阈值,检测冠状动脉狭窄≥50％的敏感度和特异度分别为42.9％(67/156)和96.9％(32/33).CTCA检测冠状动脉狭窄≥50％的敏感度和特异度分别为98.1％(153/156)和72.7％(24/33).CS和CTCA联合时,检测冠状动脉狭窄≥50％的敏感度和特异度分别为96.2％(150/156)和87.9％(29/33).结论:钙化积分对诊断冠状动脉狭窄有着很高的特异度;CTCA对诊断冠状动脉狭窄有着很高的敏感度;CTCA联合钙化积分扫描可提高冠状动脉狭窄的诊断符合率.     

血尿酸、白细胞水平与冠状动脉病变的关系

目的探讨血清尿酸（Uric acid,UA）、白细胞（WBC）水平与冠心病患者冠状动脉病变之间的关系。方法选择2011年4月～2012年4月在我院住院的疑似冠心病患者228例。根据冠脉造影结果分为冠心病组155例和正常组73例,冠心病组又分为3个亚组：单支病变组82例,双支病变组46例,三支病变组27例。分别测定冠心病组、正常组血清UA及WBC水平,观察其与冠状动脉病变的关系。结果冠心病组尿酸、白细胞水平均高于正常组,差异具有统计学意义（P〈0．05）;冠心病亚组中,随着血尿酸水平的增加,冠状动脉病变程度亦加重,差异具有统计学意义（P〈0．05）;3组间白细胞水平未见明显差异（P〉0．05）。结论血尿酸水平的升高可能与冠脉病变的程度相关;白细胞水平可能与冠心病的发生有关,但与冠脉病变的程度无关。     

FFR CT的技术原理、注意事项和结果解释

有创性血流储备分数（FFR）是评价冠状动脉血管生理功能的金标准。FFR_CT是基于冠状动脉CT血管成像的影像后处理技术,可用于评估特异性缺血病灶。大量证据支持FFR_CT有很高的诊断准确性,该技术正在从实验研究应用到临床人群。如何在日常临床工作中优化FFR_CT技术以实现病人利益最大化引起了广泛关注。总结FFR_CT的基本原理,对其注意事项和结果解读进行分析,以利于指导FFR_CT的临床应用。      

What are the basic concepts of temporal, contrast, and spatial resolution in cardiac CT?

An imaging instrument can be characterized by its spatial resolution, contrast resolution, and temporal resolution. The capabilities of computed tomography (CT) relative to other cardiac imaging modalities can be understood in these terms. The purpose of this review is to characterize the spatial, contrast, and temporal resolutions of cardiac CT in practical terms.     

The behavior of collateral circulation after coronary artery bypass surgery

The changes in coronary collateral circulation after bypass surgery were analyzed in 50 patients with coronary disease. The demonstration of collateral circulation was found to be dependent upon the severity of the coronary heart disease and the patency of the bypass. When the graft was patent, it was usually not possible to visualize the collateral circulation demonstrated preoperatively. When the bypass was occluded, the same collateral circulation as before surgery was frequenctly found.     

Individually adapted, interactive multiplanar reformations vs. semi-automated coronary segmentation and curved planar reformations for stenosis detection in coronary computed tomography angiography

Objective

To evaluate, whether semi-automated vessel extraction and curved planar reformations (“automated vessel extraction”) increases diagnostic accuracy in the detection of relevant coronary artery lesions compared to manual, interactive multiplanar interpretation (“manual approach”).

Materials and methods

50 coronary CT angiography datasets were evaluated by four independent readers (two experienced, two novice) for the presence of stenoses exceeding 50% diameter reduction. One experienced and one novice reader each used the “manual approach” for cases 1–25 and “automated vessel extraction” for cases 26–50, while the other two readers used the complementary method. Results were compared to those of invasive coronary angiography.

Results

Using the “manual approach”, 37 of 42 stenoses were correctly detected by experienced as well as novice readers. 14 vs. 17 lesions were false positive (sensitivity 88%, specificity 91% vs. 89%, PPV 73% vs. 69%, NPV 97%, n.s.). Using “automated vessel extraction”, experienced readers detected 35/42 stenoses compared to 31/42 for novice readers. 7 vs. 11 lesions were missed and 17 vs. 15 false-positive lesions reported (sensitivity 83% vs. 74%, specificity 89% vs. 90%, PPV 67%, NPV 95% vs. 93%, n.s.).In patient-based analysis, for novice readers sensitivity was higher using the “manual approach” (97%, 29/30 pts. vs. 80%, 24/30 pts., p = 0.069).

Conclusions

Semi-automated vessel extraction and curved multiplanar reconstructions do not improve the diagnostic accuracy of coronary CT angiography compared to the use of interactive multiplanar reformations. Especially for less experienced readers, the use of automatically rendered curved multiplanar reconstructions alone cannot be recommended.     

Three-dimensional teaching model for coronary angiography

In order to improve the understanding and interpretation of cine coronary arteriograms obtained in various angled projections, a three-dimensional wire model was constructed. The main coronary arteries and most important muscular branches are simulated by a wire skeleton. The model can be rotated to simulate the standard right and left anterior oblique and left lateral projections. The degree of rotation is indicated on the base of the model. By tilting the model, cephalad and caudad tube angulation can be simulated. By placing the model in front of the cine projector, the shadows of the wires can be superimposed upon the projected cine coronary arteriogram. This simple, inexpensive model has greatly improved the three-dimensional understanding of the coronary arterial tree in various angled and nonangled views and in our practice had led to the development of additional useful projections.     

Plaque volume,composition, and fraction versus ischemia and outcomes in patients with coronary artery disease

BackgroundThe various plaque components have been associated with ischemia and outcomes in patients with coronary artery disease (CAD). The main goal of this analysis was to test the hypothesis that, at patient level, the fraction of non-calcified plaque volume (PV) of total PV is associated with ischemia and outcomes in patients with CAD. This ratio could be a simple and clinically useful parameter, if predicting outcomes.MethodsConsecutive patients with suspected CAD undergoing coronary computed tomography angiography with selective positron emission tomography perfusion imaging were selected. Plaque components were quantitatively analyzed at patient level. The fraction of various plaque components were expressed as percentage of total PV and examined among patients with non-obstructive CAD, suspected stenosis with normal perfusion, and those with reduced myocardial perfusion. Clinical outcomes included all-cause mortality and myocardial infarction.ResultsIn total, 494 patients (age 63 ​± ​9 years, 55% male) were included. Total PV and all plaque components were significantly larger in patients with reduced myocardial perfusion compared to patients with normal perfusion and those with non-obstructive CAD. During follow-up 35 events occurred. Patients with any plaque component ​≥ ​median showed worse outcomes (log-rank p ​< ​0.001 for all). In addition, low-attenuation plaque ​≥ ​median was associated with worse outcomes independent of total PV (adjusted HR: 2.754, 95% CI: 1.022–7.0419, p ​= ​0.045). The fractions of the various plaque components were not associated with outcomes.ConclusionLarger total PV or any plaque component at patient level are associated with abnormal myocardial perfusion and adverse events. The various plaque components as fraction of total PV lack additional prognostic value.     

Coronary artery calcium screening: current status and recommendations from the European Society of Cardiac Radiology and North American Society for Cardiovascular Imaging

Current guidelines and literature on screening for coronary artery calcium for cardiac risk assessment are reviewed for both general and special populations. It is shown that for both general and special populations a zero score excludes most clinically relevant coronary artery disease. The importance of standardization of coronary artery calcium measurements by multidetector CT is discussed. This consensus article is being published concurrently in the Springer Journal International Journal of Cardiovascular Imaging.     

ABI联合baPWV与双源CT冠状动脉成像的相关性研究

目的 通过与双源CT对比,评价踝臂指数(ABI)、肱-踝脉搏波速度(baPWV)在辅助预测冠状动脉病变的临床价值.方法 搜集经双源CT冠状动脉造影(CTA)检查显示冠状动脉狭窄程度≥50％并行ABI及baPWV检测的50例患者,分析ABI、baPWV与CTA冠状动脉狭窄支数、节段以及斑块数目的相关性.结果 单支、两支和三支病变组间的ABI值、baPWV值存在差异(P＜0.05),随着病变支数的增加,ABI逐渐减小,baPWV逐渐增加.两支病变时,ABI均值＜0.9;三支病变时,baPWV均值＞1400 cm/s,说明可能baPWV值更敏感.ABI＜ 0.9、ABI＞0.9两组间检出斑块数无差异(P＞0.05),狭窄节段数有统计学差异(P＜0.02);baPWV＜ 1400 cm/s、baPWV＞1400 cm/s组间斑块数及狭窄节段有统计学差异(P＜0.05).表明ABI ＜0.9、baPWV＞ 1400 cm/s时冠状动脉狭窄可能性较大,baPWV＞ 1400 cm/s时冠状动脉斑块出现的可能性较大.结论 ABI和baPWV与DSCT冠状动脉的狭窄支数、斑块数及狭窄节段数有关,可以用于辅助预测冠心病的严重程度.     

Coronary venous anatomy and anomalies

Coronary venous anatomy can be divided into the greater cardiac venous system and the lesser cardiac venous system. With protocol optimization, including appropriate contrast bolus timing, coronary veins can be depicted with excellent detail on CT. Knowledge of variant coronary venous anatomy can sometimes play a role in pre-procedural planning. Analysis of the coronary venous anatomy on CT can detect coronary venous anomalies that cause right to left shunts with risk of stroke, left to right shunts, and arrhythmias.     

多层螺旋CT冠状动脉成像的临床应用探讨

目的：探讨多层螺旋CT冠状动脉成像技术的应用和临床价值。材料和方法：对32例（包括3例冠状动脉搭桥术后和1例冠状动脉成形术及支架置入术后病人）进行了MSCT冠状动脉成像检查，并进行CT图像重建后处理，重建出各主要血管，对冠状动脉搭桥术后的病人重建出桥血管及含支架血管。分析MSCT对冠状动脉的显示能力，并分析是否有管壁钙化和软性斑块，评价管腔狭窄及其程度。对桥血管和支架的显示及通畅性进行评价。结果：MSCT冠状动脉成像对冠状动脉近中段显示清晰，显示率达90％以上；对冠状动脉钙化和软性斑块显示良好，对冠状动脉狭窄显示较佳。7根搭桥血管其中有1根可见约75％-90％的狭窄，其余均通畅，支架显示良好。结论：MSCT冠状动脉成像可作为冠状动脉粥样硬化疾患筛选手段，对血管搭桥术和支架放置并进行术后评价有很高的价值。     

Detection,visualization and evaluation of anomalous coronary anatomy on 16-slice multidetector-row CT

Early identification and evaluation of relatively frequent anomalous coronary anatomy is quite relevant because of the occurrence of sudden cardiac death or related symptoms of myocardial ischemia. Selective coronary angiography (CAG) is invasive, expensive and cannot always provide the required information adequately. Recently, non-invasive imaging techniques such as magnetic resonance imaging and multidetector-row computed tomography (MDCT) have been shown to provide a good anatomical view of the coronary artery tree. This study aims to demonstrate the value of 16-MDCT for evaluation of anomalous coronary anatomy. In 13 patients scanned using 16-MDCT, six different coronary anomalies were diagnosed [two absent left main, one single vessel left coronary artery (LCA), three LCA originating from the right (two with interarterial course), six right coronary artery originating from the left, one double left anterior descending (LAD)]. Mean diagnostic quality, recorded by two observers using a 5-point scale (1= non-diagnostic to 5= excellent diagnostic quality), resulted in a mean score of 3.73 (SD 1.19) without any non-diagnostic result. MDCT offers an accurate diagnostic modality to visualize the origin and course of anomalous coronary arteries by a three-dimensional display of anatomy. Shortcomings in CAG can be overcome by the use of contrast-enhanced MDCT.