双层螺旋CT冠状动脉钙化积分评估

目的 :对冠状动脉钙化进行定性判断 ,并对其钙化程度进行积分评估和相关技术探讨。方法 :采用GELightspeed 2 .0螺旋CT ,结合心电门控技术 ,对临床怀疑冠心病及要求体检者共 16例行心脏平扫。结果 :CT成像 ,应用SmartScore软件行冠状动脉钙化积分评估。 9例可见双侧冠状动脉多发钙化 ,3例高积分病例随后行DSA检查 ,进一步判断冠脉狭窄程度 ;3例单支冠状动脉钙化 ;4例未见明显钙化 ,其中 1例右侧冠状动脉密度增高 ,有粥样硬化斑块。结论 :螺旋CT冠状动脉钙化积分评估 ,可作为临床诊断重要辅助参考依据 ,是一种值得推广的技术。     

多层螺旋CT冠状动脉成像扫描技术的质量分析

应用MSCT冠状动脉成像扫描,能够较为清晰地显示冠状动脉,三维重建能获得多角度以及动态的图像,图像质量成为影响诊断可靠性的重要因素。为此,我们应用东芝 Aquilion M16层CT扫描机,开展CT冠状动脉成像扫描技术的质量控制研究,现就相关成像扫描技术质量研究分析如下。     

超高速CT揭示男女无症状者冠状动脉钙化的发生率及程度的差异

冠状动脉钙化(CAC)是动脉内膜粥样硬化的标志。以往多用X线透视观察,但敏感性低。 作者使用Imatron C-100CT机(超高速CT机-UFCT),自心底部冠状动脉近端连续向足侧扫描20层,层厚3mm,时间100ms,应用心电门控,每于舒张期相当80％RR间期时扫描。患者在整个20层扫描期间屏气。获得图象后看定位准确与否,必要时加扫层面。然后对钙化评分:每一病灶的面积(mm~2)乘以其CT峰值即为该病灶的钙化分数。钙化评分由冠状动脉主要分支(左主支、左前降支、左旋支和右     

多层螺旋CT冠脉造影的标准体位

目的:探讨建立多层螺旋CT冠脉造影标准体位.材料和方法:对120例临床怀疑冠心病患者进行16层螺旋CT心电门控平扫及增强扫描.所有患者用舒张期增强扫描重建像行最大密度投影(MIP)重建及容积漫游技术(VRT)重建,其中30例与常规冠状动脉造影对照.总结16层螺旋CT心脏冠状动脉造影不同体位的显示情况,得出CT冠状动脉造影统一体位.结果:分别定义了6个MIP重建体位和9个VRT重建体位.结论:多层螺旋CT冠状动脉造影是一种无创、简便、优良的冠状动脉造影方法,建立起标准造影体位有利于对冠脉病变进行更全面评价.     

多排螺旋CT冠状动脉成像技术

目的 探讨多排螺旋CT在冠状造影中的应用，对冠状动脉进行评价(钙化，狭窄及冠状动脉瘤)对内支架及搭桥患者进行术后随访评价。方法 GE light speed ultra扫描机对患者在肘前静脉用高压注射器注入对比剂后，采用回顾性心电门控及分段数据采集方式，对患者进行心脏成像扫描。结果 冠状动脉显示清晰，满足诊断需要。MSCT冠状动脉造影是一种无创性，能获得较好的心脏三维图像，对冠状动脉病的诊断有很大潜力，在这项技术中，注药速度、延时时间、扫描层厚、扫描速度是紧密相关的，恰当与否直接影响图像质量。     

混合迭代重建混合权重对心脏CT冠状动脉钙化积分影响

目的:评价混合迭代重建算法(ASIR-V)混合权重对心脏CT冠状动脉钙化积分及危险分层计算结果的影响.方法:100例心电门控心脏CT钙化积分扫描原始数据利用不同混合权重ASIR-V算法重建,包括ASIR-V 0％即(FBP)、ASIR-V 20％、ASIR-V 40％、ASIR-V 60％、ASIR-V 80％、ASI...     

前瞻性心电门控扫描在冠脉支架随访中的应用

目的探讨前瞻性心电门控扫描在冠状动脉支架随访中的可行性。方法 77例冠状动脉支架植入术后患者行冠状动脉CT血管成像检查,按照心率不同分为两组,分别采用回顾性心电门控及前瞻性心电门控扫描。比较两组图像支架内及支架近端的CT值、噪声、信噪比(SNR)、支架内CT值净增比(SAIR)、图像质量主观评分及辐射剂量。定量数据表示为平均数±标准差。结果回顾性心电门控组的心率快于前瞻性心电门控组(P 0. 05)。两组图像支架内及支架近端的CT值、噪声、信噪比(SNR)、支架内CT值净增比(SAIR)以及图像质量主观评分差异均无统计学意义(P0. 05)。前瞻性心电门控组辐射剂量显著降低,平均有效辐射剂量为(2. 40±0. 99) m Sv,组间差异具有统计学意义(P 0. 05)。结论对于冠脉支架植入术后的患者,前瞻性心电门控扫描方案在降低辐射剂量的同时,可获得满意的图像质量。     

评价“胸痛三联排除”的CT冠状动脉血管成像扫描方法在疑有低到中度急性冠状动脉综合征危险的急诊病人64层CT检查中的应用

目的比较一组接受前瞻性心电门控64层CT冠状动脉成像病人及另一组接受回顾性心电门控64层CT冠状动脉病人的成像质量及病人放射剂量。方法本研究依从HIPAA法案并得到了机构审查委员会的批准。由于设计是回顾性研究故不需要知情同意。2位独立阅片者分别对100例病人心脏CT成像（每组各50例）的冠状动脉进行分段影像质量评分和综合评分。计算观察者间偏差。记录对应实际扫描Z轴长度的病人放射剂量，以Z轴长度为12cm的典型心脏计算标准化剂量。结果2组病例的临床特征及CT参数匹配良好。     

16层螺旋CT冠状动脉血管成像技术临床应用

目的:探讨16层螺旋CT冠状动脉成像技术临床应用价值。方法:对45例临床诊断或可疑冠心病的住院患者行16层螺旋CT冠状动脉回顾性心电门控平扫及增强扫描。将增强扫描图像传送到Wizard图像工作站进行最大密度投影(MIP)、多平面重组(MPR)、曲面重组(CPR)、容积再现技术(VRT)及平带多平面重组(RMPR)。并将VRT及MIP重组像为参照,用平扫图像对冠状动脉各支段进行钙化积分。结果:左冠状动脉主干(LM)、左前降支近中段(LAD1、LAD2)、第一对角支(D1)、左回旋支(LCX)及右冠状动脉近段(RCA1)显示均45例(100%),左前降支远段(LAD3)23例(51%),第二对角支(D2)30例(67%),第三对角支(D3)24例(53%),第一左缘支(M1)36例(80%),第二缘支(M2)28例(62%),右冠状动脉中段(RCA2)41例(91%),右冠状动脉远段(RCA3)43例(96%)及后降支(PDA)34例(76%)。左冠状动脉主干钙化12例(27%),左前降支近中段钙化有29例(64%),左回旋支钙化例数22例(49%),右冠状动脉近中段钙化有24例(53%)。结论:16层螺旋CT可对冠状动脉进行钙化积分并准确显影,是冠状动脉粥样硬化疾病筛选和诊断的首选方法。     

冠脉钙化积分扫描对前瞻性门控冠脉成像扫描长度的界值确定研究

目的:本研究通过采用钙化积分影像控制前门控扫描长度并与采用定位片方式进行辐射量对比,评价其临床应用价值.方法.70例拟诊或确诊冠状动脉粥样硬化性心脏病的患者随机分为A、B两组,A组33例,采用冠脉钙化积分扫描数据进行CTCA扫描范围界定,拟扫描范围为左冠状动脉主干出现层面以上1 cm至心尖部层面以下1 cm;B组37例...     

Causes of interscan variability of coronary artery calcium measurements at electron-beam CT

RATIONALE AND OBJECTIVES: The authors performed this study to investigate the causes of interscan variability of coronary artery calcium measurements at electron-beam computed tomography (CT). MATERIALS AND METHODS: Two sets of electron-beam CT scans were obtained in 298 consecutive patients who underwent electron-beam CT to screen for coronary artery calcium. Interscan variations of coronary artery calcium characteristics and the effects of heart rate, electrocardiographic (ECG) triggering method, image noise, and coronary motion on interscan variability were analyzed. RESULTS: The interscan mean variabilities were 21.6% (median, 11.7%) and 17.8% (median, 10.8%) with the Agatston and volumetric score, respectively (P < .01). Variability decreased with increasing calcification score (34.6% for a score of 11-50 and 9.4% for a score of 400-1,000, P < .0001). The absolute difference in Agatston score between scans was 44.1 +/- 95.6. The correlation coefficient between the first and second sets of scans was 0.99 (P < .0001). Lower interscan variability was found in younger patients (<60 years), patients with stable heart rates (heart rate changing less than 10 beats per minute during scanning), patients with no visible coronary motion, and those with an optimal ECG triggering method (P < .05 for all). Results of multivariate logistic analysis showed that changes in calcium volume, mean attenuation, and peak attenuation were significant predictors of interscan variability and caused the interscan variations of the coronary artery calcium measurements (r2 = 0.83, P < .0001). CONCLUSION: Coronary calcification at electron-beam CT varies from scan to scan. Volumetric scoring and optimal ECG triggering should be used to reduce interscan variability. Baseline calcium score and interscan variability must be considered in the evaluation of calcium progression.     

多层螺旋CT冠脉钙化积分诊断冠心病及风险预测的临床价值

目的:探讨多层螺旋CT冠脉钙化积分在冠心病的诊断及早期风险性预测中的临床价值.材料和方法:总结90例受检者资料,分析多层螺旋CT冠脉钙化积分与其年龄、血脂及心电图的关系.结果:多层螺旋CT冠脉钙化积分与受检者的年龄、血脂及心电图的缺血改变具有显著的正相关:年龄越大、血脂越高,钙化发生率、钙化的程度及平均钙化积分值越高;随着钙化积分的增高,心电图缺血改变的发生率逐渐增高.结论:多层螺旋CT冠脉钙化积分检查经济、方便、无创,适用于冠心病的筛查及风险性预测.     

The relationship between coronary artery calcification detected by non-gated multi-detector CT in patients with suspected ischemic heart disease and myocardial ischemia detected by thallium exercise stress testing

OBJECTIVE: To examine whether we could predict myocardial ischemia when coronary artery calcification is detected by non-gated multidetector CT in patients with suspected ischemic heart disease. METHODS: Eighty-three patients suspected of having ischemic heart disease (55 men, 28 women; age range 36-83 years; mean age 68 years) underwent multidetector CT and T1-201 single photon emission computed tomography. Prediction of myocardial ischemia by coronary arterial calcification detected on CT was evaluated by comparing the coronary artery territories that showed calcification with the area of myocardial ischemia determined by SPECT. The sensitivity, specificity, positive predictive value, and negative predictive value of multidetector CT for predicting myocardial ischemia were calculated. Coronary angiography was also examined and compared with multidetector CT. Risk factors, including hypertension, smoking, hyperlipidemia, diabetes, and family history, were compared for evidence of coronary artery calcification detected by multidetector CT and myocardial ischemia detected by thallium nuclear scans. RESULTS: For analysis by patients, the sensitivity, specificity, positive predictive value, and negative predictive value of coronary artery calcification for myocardial ischemia detection were 65, 63, 56, and 71%, respectively. Similarly, for analysis by coronary arterial territories, those values were 56, 77, 41 and 86%, respectively. Coronary stenosis on CAG was also related to the ischemia determined by SPECT and calcification on multidetector CT. Ischemia was better influenced by risk factors than was coronary arterial calcification. CONCLUSIONS: For analysis by coronary arterial territories, the specificity and negative predictive value of coronary arterial calcification seen by multidetector CT are relatively high.     

16层螺旋CT冠状动脉钙化积分的临床分析

目的评价16层螺旋CT冠状动脉钙化积分在冠心病诊断中的临床应用价值。方法 48例患者均行16层螺旋CT冠状动脉钙化积分检查和冠状动脉造影。结果 冠心病组的平均钙化分数为475.5±41.2,与对照组的116.3±21.3差异有统计学意义(P<0.05),冠状动脉造影的结果与16层螺旋CT冠状动脉钙化积分结果对照,以积分>400为阳性,<400为阴性。两者之间的差异无统计学意义(P>0.05)。结论 16层螺旋CT冠状动脉钙化积分分析可以作为冠心病高危人群筛选,高积分值与冠脉狭窄有明显的相关性。     

心电编辑对提高双源CT冠脉图像质量的初步研究

目的:探讨心电编辑在改善双源CT冠脉图像质量中的作用。方法:以冠脉分支为单位,回顾性分析60例心率变异过大或心律失常患者双源CT冠脉成像编辑前后的图像质量,总结不同类型的心电编辑方法。结果:60例心率变异过大或心律失常患者,心率范围为55～269次/min,平均心率(92.8±31.9)次/min,冠脉图像编辑前后的图像质量总评分分别为2.26±1.03、3.5±0.61(t=-17.85,P=0.001);表明编辑前后图像质量的评分有统计学意义,编辑后图像质量明显改善。结论:心电编辑技术可以明显改善心率变异过大或心律失常患者双源CT冠脉成像的图像质量。     

Variability of repeated coronary artery calcium measurements by 16-MDCT with retrospective reconstruction

OBJECTIVE: High reproducibility on coronary calcium scoring is an important factor in monitoring the progression of coronary atherosclerosis. The purposes of this study were, using a 16-MDCT scanner with retrospective reconstruction, to compare the effects of thin-slice images and overlapping image reconstruction on the reproducibility of coronary calcium scoring and to compare 16-MDCT with electron beam CT (EBCT). MATERIALS AND METHODS: Fifty patients underwent two sequential examinations using both EBCT and MDCT. For MDCT, images were reconstructed from the same raw data using the following thicknesses and increments (thickness/increment): 1.25 mm/1.25 mm, 2.5 mm/2.5 mm, and 2.5 mm/1.25 mm. The Agatston, volume, and mass scores were calculated on four pairs of image sets. Statistical analysis was performed to determine significant differences in interscan variability among image acquisition protocols and among measurement algorithms. RESULTS: Overlapping reconstructed images (thickness/increment, 2.5 mm/1.25 mm) obtained on a 16-MDCT scanner showed the lowest variability (mean, 13%; median, 10%) when compared with the Agatston score. CONCLUSION: The use of 16-MDCT with overlapping reconstruction by retrospective reconstruction, yielding low variability of coronary artery calcium measurement on two sequential scans, has an advantage over EBCT in monitoring the progression of atherosclerosis.     

Image quality of three-dimensional electron beam coronary angiography

PURPOSE: This study identifies reasons for poor image quality and nonassessability of coronary artery segments and compares results between early and late diastolic triggering on coronary electron beam angiography (EBA). METHOD: One hundred patients referred for EBA were studied. Contrast-enhanced transaxial coronary images were acquired using electrocardiographic (ECG) triggering and reconstructed three dimensionally using volume-rendering techniques. The image quality of coronary segments and image artifacts were analyzed statistically. RESULTS: Volume rendering failed in seven patients (7%) owing to cardiac and breathing motions. Image quality was the best with the left main (LM) and worst with the left circumflex (LCX) coronary arteries (p < 0.001). The image quality decreased systematically from proximal to distal within each coronary artery (p < 0.001). Forty percent R-R interval triggering on ECG was better than 80% for image quality. The nonassessable segments occurred in 3% of LM, 2, 8, and 5% of proximal, 24, 22, and 12% of mid, and 64, 45, and 20% of distal segments of the left anterior descending, LCX, and right coronary arteries, respectively (p < 0.05). CONCLUSION: The major limitations of coronary EBA were suboptimal spatial resolution and image artifacts. The image quality could be improved by using optimal ECG triggering.     

Increased prevalence of coronary artery calcification in patients with suspected pulmonary embolism

RATIONALE AND OBJECTIVES: The authors explored the possibility that patients with suspected pulmonary embolism are at high risk for coronary artery disease. To this purpose, they compared the presence of coronary artery calcification on computed tomography (CT) in patients suspected of pulmonary embolism with age- and gender-matched controls. MATERIALS AND METHODS: The CT scans of 214 patients were reviewed. Of those, 107 consecutive patients (50%) had pulmonary CT angiography for suspected pulmonary embolism (PE group). The remaining 107 age- and gender-matched patients were scanned for reasons other than pulmonary embolism (non-PE group). All CT scans were performed with the same 8-detector-row multislice scanner. Two radiologists reviewed scans of 5-mm slices using a five-grade modified coronary calcium scoring system: 1 = no calcification; 2 = minimal calcification; 3 = mild calcification; 4 = moderate calcification; and 5 = severe calcification. The Marginal Homogeneity test was used to compare the distribution and severity of calcification in the two groups. RESULTS: Of 107 patients in the PE group, seven (6.54%) had pulmonary embolism detected on CT. Coronary artery calcification was detected in 61 patients (57%) in the PE group compared with 42 patients (39%) in the non-PE group. The Marginal Homogeneity test showed that patients with pulmonary embolism symptoms were 2.9 times more likely to have calcification detected compared with those patients who had chest CT for some other reason (P = .0034). However, in patients in whom coronary artery calcification was detected, the distribution of severity of calcification was the same in both groups. CONCLUSION: Assuming coronary artery calcification indicated coronary atherosclerosis, patients undergoing CT for suspected pulmonary embolism may be at high risk for coronary artery disease.     

低剂量64层螺旋CT测定冠状动脉钙化积分的准确性评价

目的 探讨低剂量64层螺旋CT测定冠状动脉钙化积分的准确性。方法 2006年8月至2009年9月间对43名冠状动脉钙化的患者连续进行2次64层螺旋CT扫描,管电流时间积分别为常规剂量(100 mAs)和低剂量(55 mAs),其余参数不变,由2名放射科副主任医师测定钙化积分并测量升主动脉CT值的均数及标准差。结果 低剂量与常规剂量钙化总积分和独立血管钙化积分取平方根转换后均直线相关(r =0.998、0.997)。低剂量管电流时间积所测升主动脉根部的CT值的均数与2倍标准差之和小于130 HU,可满足所要求的信噪比,与常规剂量扫描辐射剂量(1.32±0.08)mSv相比较,低剂量扫描有效剂量降低0.6 mSv(P <0.05)。结论 低剂量前瞻性心电门控64层MDCT钙化积分扫描图像能满足测量需要,测量结果具有较高的准确性。