Multidetector computed tomography myocardial perfusion imaging during adenosine stress.

OBJECTIVES: The purpose of this study is to validate the accuracy of multidetector computed tomography (MDCT) to measure differences in regional myocardial perfusion during adenosine stress in a canine model of left anterior descending (LAD) artery stenosis, during first-pass, contrast-enhanced helical MDCT. BACKGROUND: Myocardial perfusion imaging by MDCT may have significant implications in the diagnosis and treatment of coronary artery disease. METHODS: Eight dogs were prepared with a LAD stenosis, and contrast-enhanced MDCT imaging was performed 5 min into adenosine infusion (0.14 to 0.21 mg/kg/min). Images were analyzed using a semiautomated approach to define the regional signal density (SD) ratio (myocardial SD/left ventricular blood pool SD) in stenosed and remote territories, and then compared with microsphere myocardial blood flow (MBF) measurements. RESULTS: Mean MBF in stenosed versus remote territories was 1.37 +/- 0.46 ml/g/min and 1.29 +/- 0.48 ml/g/min at baseline (p = NS) and 2.54 +/- 0.93 ml/g/min and 8.94 +/- 5.74 ml/g/min during adenosine infusion, respectively (p < 0.05). Myocardial SD was 92.3 +/- 39.5 HU in stenosed versus 180.4 +/- 41.9 HU in remote territories (p < 0.001). There was a significant linear association of the SD ratio with MBF in the stenosed territory (R = 0.98, p = 0.001) and between regional myocardial SD ratio and MBF <8 ml/g/min, slope = 0.035, SE = 0.007, p < 0.0001. Overall, there was a significant non-linear relationship over the range of flows studied (LR chi-square [2 degrees of freedom] = 31.8, p < 0.0001). CONCLUSIONS: Adenosine-augmented MDCT myocardial perfusion imaging provides semiquantitative measurements of myocardial perfusion during first-pass MDCT imaging in a canine model of LAD stenosis.     

Coronary vasospasm produces reversible perfusion defects observed during adenosine triphosphate stress myocardial single-photon emission computed tomography

BACKGROUND: Adenosine triphosphate stress thallium-201 single-photon emission computed tomography (ATP-SPECT) is useful for diagnosing coronary artery disease (CAD), although sometimes false positive results are observed. It has not been established whether a coronary spasm is responsible for the false positive findings during ATP-SPECT. HYPOTHESIS: We investigated whether coronary spasm is one of the factors which produces reversible defects on ATP-SPECT. METHODS: Eighty-six patients (mean age: 62 y; 58 men) who underwent both spasm-provocation testing by coronary angiography and ATP-SPECT, were selected for the study. Patients with coronary narrowing (>30%), myocardial infarction, or heart failure were excluded. Patients were divided into 2 groups based on whether the spasm-provocation test result was positive (vasospastic angina [VSA] group, n = 46) or negative (non-VSA group, n = 39). RESULTS: The body mass index was lower in the VSA group than in the non-VSA group (p = 0.005). On ATP-SPECT imaging, any type of reversible defect was observed more frequently in the VSA group (68%) than in the non-VSA group (36%, p = 0.0027). Logistic regression analysis demonstrated that the presence of reversible defects was one of the factors accounting for the presence of coronary vasospasm (p = 0.0022, R2 = 0.172). CONCLUSIONS: The findings suggest that reversible defects on ATP-SPECT imaging are frequently present in patients with coronary vasospasm. Coronary spasm may be considered as 1 of the factors, which produce reversible defects on ATP-SPECT, observed in patients with chest symptoms and angiographically normal coronary arteries.     

Relationship between noninvasive coronary angiography with multi-slice computed tomography and myocardial perfusion imaging.

OBJECTIVES: The aim of this study was to perform a head-to-head comparison between multi-slice computed tomography (MSCT) and myocardial perfusion imaging (MPI) in patients with an intermediate likelihood of coronary artery disease (CAD) and to compare non-invasive findings to invasive coronary angiography. BACKGROUND: Multi-slice computed tomography detects atherosclerosis, whereas MPI detects ischemia; how these 2 techniques compare in patients with an intermediate likelihood of CAD is unknown. METHODS: A total of 114 patients, mainly with intermediate likelihood of CAD, underwent both MSCT and MPI. The MSCT studies were classified as having no CAD, nonobstructive (<50% luminal narrowing) CAD, or obstructive CAD. Myocardial perfusion imaging examinations were classified as showing normal or abnormal (reversible and/or fixed defects). In a subset of 58 patients, invasive coronary angiography was performed. RESULTS: On the basis of the MSCT data, 41 patients (36%) were classified as having no CAD, of whom 90% had normal MPI. A total of 33 patients (29%) showed non-obstructive CAD, whereas at least 1 significant (> or =50% luminal narrowing) lesion was observed in the remaining 40 patients (35%). Only 45% of patients with an abnormal MSCT had abnormal MPI; even in patients with obstructive CAD on MSCT, 50% still had a normal MPI. In the subset of patients undergoing invasive angiography, the agreement with MSCT was excellent (90%). CONCLUSIONS: Myocardial perfusion imaging and MSCT provide different and complementary information on CAD, namely, detection of atherosclerosis versus detection of ischemia. As compared to invasive angiography, MSCT has a high accuracy for detecting CAD in patients with an intermediate likelihood of CAD.     

Myocardial perfusion imaging and infarct characterization using multidetector cardiac computed tomography

Until recently, computed tomography coronary angiography was restricted to the anatomical assessment of coronary stenosis, whereas the functional significance of coronary lesions remained outside of its scope. Nevertheless, the kinetics of iodinated contrast is similar to gadolinium-diethylenetriamine pentaacetic acid used in contrast-enhanced magnetic resonance imaging, allowing assessment of myocardial perfusion and viability by cardiac computed tomography.     

计算机断层扫描腺苷负荷心肌灌注成像定量参数心肌血流量与心血管危险因素的关系

目的通过计算机断层扫描(computed tomography,CT)腺苷负荷心肌灌注成像获取定量参数心肌血流量(myocardial blood flow,MBF),对MBF与心血管危险因素之间的关系进行分析。方法选取2018年6月至2019年4月怀疑冠状动脉粥样硬化性心脏病(冠心病)的南京医科大学第一附属医院门诊及住院患者56例,分别在本院放射科采用第3代双源冠状动脉CT血管成像(coronary CT angiography,CCTA)联合CT心肌灌注(CT myocardial perfusion,CTP)获取MBF值;在本院检验科抽取空腹血4 m L,获取生化和血常规等检验结果。结果56例患者根据CCTA联合CTP结果判定为冠心病的有26例,非冠心病的30例。其中冠心病组灌注异常18例,灌注正常8例;非冠心病组灌注异常9例,灌注正常21例。冠心病组MBF值高于非冠心病组,差异有统计学意义[120(100~122.5)mL·100 mL^-1·min^-1vs.90(65~120)mL·100 mL^-1·min^-1,P<0.05]。按照MBF中位数分3组,3组之间的MBF、年龄、载脂蛋白A,葡萄糖、尿素氮、血小板计数和Gensini积分等比较,差异有统计学意义(P<0.05)。Spearman相关分析显示,MBF与尿素氮、Gensini积分呈负相关,与血小板计数呈正相关。多元线性回归分析显示,Gensini积分、低密度脂蛋白胆固醇、尿素氮、血小板与因变量MBF的回归模型存在统计学意义。结论MBF可能受到尿素氮、低密度脂蛋白胆固醇、血小板、Gensini积分等多因素的综合影响。     

核素心肌灌注显像与多层螺旋 CT 诊断冠心病的对比分析

目的 对比分析核素心肌灌注显像(MPI)与多层螺旋CT(MSCT)对冠心病(CAD)的诊断价值,并评价两者联合诊断CAD的临床价值.方法 对43例患者(疑诊CAD 36例,确诊CAD 7例)行冠状动脉造影(CAG)、MPI和MSCT检查,且三项检查均在2个月内进行.采用半定量法对MPI结果 进行分析,SDS(总差值分)>1判定为可逆性心肌缺血,并将各心肌节段定位于其所对应的冠状动脉;参照国际上通用的目测直径法对MSCT结果 进行判定,即至少1支主要冠状动脉或其主要分支狭窄程度≥50%判定为阳性.以CAG为诊断CAD的"金标准",比较MPI与MSCT对CAD患者的诊断价值和对病变血管(狭窄程度≥50%)的检出价值.结果 MPI和MSCT对CAD患者诊断的灵敏性、特异性及准确性分别是79.17%、84.21%及81.40%和83.33%、89.47%及86.05%;MPI和MSCT对病变血管诊断的灵敏性、特异性及准确性分别是53.19%、89.02%及75.97%和70.21%、95.12%及86.05盼,两者差异均无统计学意义(P>0.05).结论 MPI和MSCT诊断CAD差异无统计学意义.两者优势互补,是筛选、诊断CAD的无创性检查手段,宜结合使用.     

冠脉64排螺旋CT与腺苷负荷心肌灌注显像对冠心病的诊断价值

目的：探讨冠脉64排螺旋CT（CTA）与腺苷负荷心肌灌注显像对冠心病的诊断价值。方法：入选临床诊断或疑诊为冠心病的患者66例,以冠状动脉造影作为冠心病诊断的金标准,所有患者均进行冠脉64排螺旋CT,腺苷负荷心肌灌注显像与冠状动脉造影检查。结果：与冠状动脉造影比较,64排螺旋CT对冠心病诊断的敏感性为87.10%（27/31）,特异性为97.14%（34/35）,准确性为92.42%（61/66）,腺苷负荷心肌灌注显像敏感性为93.55%（29/31）,特异性为85.71%（30/35）,准确性为89.39%（59/66）。冠脉64排螺旋CT与腺苷负荷心肌灌注显像在诊断冠心病的准确性上无显著差别（P〉0.05）。结论：冠脉64排螺旋CT与腺苷负荷心肌灌注显像诊断冠心病的准确性无显著差别,结果可靠,应予推广。     

多层螺旋CT在冠状动脉支架术后的应用

目的：探讨多层螺旋CT(MSCT)冠状动脉成像在冠状动脉支架术后的应用价值。方法：21例患者在放置冠状动脉支架后行MSCT冠状动脉成像，其中5例与选择性冠状动脉造影进行了对照。结果：21例的27枚冠状动脉支架中，能满足影像学评价的有25枚，占92％，不能满足评价的有2枚，占8％；5例同时作导管法冠状动脉造影者两种检测方法结果相同。结论：MSCT冠状动脉成像是一种简便易行，安全有效的无创性检查方法，可作为冠状动脉支架术后随访观察的手段。     

Noninvasive plaque imaging using multislice detector spiral computed tomography

Multislice detector spiral computed tomography (MSCT) is a noninvasive modality for visualization and evaluation of atherosclerosis in vivo in different arterial beds. Rapid technical advances led to a significant improvement of the diagnostic accuracy of coronary MSCT angiography. The most popular clinical application with best scientific Medical evidence of MSCT is the noninvasive detection and quantification of coronary calcifications. In particular, the concept of determining coronary artery age by evaluating an individual's biological age, rather than his or her chronological age, is attractive and currently under scientific evaluation. In addition to evaluating contrast-enhanced coronary arteries, different stages of atherosclerosis can be visualized. By comparative studies with intracoronary ultrasound, it could be shown that echogenicity corresponds well with the density measured within atherosclerotic plaques expressed by Hounsfield units using MSCT. Although the method is improving continuously and is still under development, the potential of MSCT to evaluate plaque composition and plaque volumes noninvasively in vivo is promising.     

Direct comparison between pharmacological stress with adenosine triphosphate disodium and exercise stress myocardial perfusion imagings

To clarify the significance of adenosine triphosphate disodium stress myocardial perfusion imaging (ATP-MPI), we directly compared the findings of ATP-MPI with those of exercise stress myocardial perfusion imaging (Ex-MPI). ATP-MPI, Ex-MPI, and coronary angiography (CAG) were performed within 60 days in 17 coronary artery disease patients with mean age of 62.1+/-7.9 years. CAG revealed single-vessel disease (SVD) in 10 patients and multivessel disease (MVD) in seven patients. The summed stress score (SSS) of ATP-MPI was significantly higher than that of Ex-MPI (10.0 [7.8-14.3] vs. 8.0 [4-18], P<0.05). No difference in the SSS was observed between ATP-MPI and Ex-MPI in patients with SVD (8.0 [6.0-9.0] vs. 8.0 [6.0-10.0], NS), whereas this difference was significant in patients with MVD (15.0 [14.0-22.8] vs.9 [7.3-16.3], P<0.05). There was no difference in the summed rest score between ATP-MPI and Ex-MPI. The univariate logistic analysis showed that "MVD" was the significant factor influencing to the overt discrepancy between ATP-MPI and Ex-MPI (odds ratio: 9.0, 95% confidence interval: 1.07-75.84, P=0.043). The accuracy of ATP-MPI and Ex-MPI in detecting the territory of stenotic coronary vessel or previous myocardial infarction was 98.0% and 92.1% (NS), respectively. In conclusion, ATP-MPI is useful for detecting potential ischemic areas that cannot be detected by Ex-MPI, particularly in patients with MVD.     

QT dispersion at rest and during adenosine stress myocardial perfusion imaging correlation with Myocardial Jeopardy Score

BACKGROUND: The usefulness of QT dispersion (QTd) during adenosine myocardial perfusion imaging (MPI) to predict severity of coronary artery disease (CAD) has not been studied. METHODS: Eighty-eight patients referred for diagnostic cardiac catheterization after abnormal MPI were included. Thirty-four patients with no stenosis (Duke Score = 0) were included in Group 1, and 54 patients with significant CAD (Duke Score > or = 2) formed Group 2. Resting and stress QTd and prolongation in QTd (delta QTd) were measured and evaluated as independent predictors for severity of CAD. RESULTS: Resting QTd was higher in Group 2 as compared with Group 1. During peak infusion of adenosine, QTd was significantly prolonged in Group 1 but remained unchanged, or fixed, in Group 2. In addition, in patients with significant CAD, resting QTd positively correlated with the Duke Score. On multiple regression analysis; independent predictors for significant CAD (odds ratio [OR], 95% confidence interval [CI], p-value) were resting QTd (4.9, 95% CI 1.1-21.6, < 0.05 for fourth Quartile compared with first Quartile) and delta QTd (4.0, 1.4-11.2, < 0.01 for first and second Quartiles compared with third and fourth Quartiles). CONCLUSION: In patients with abnormal stress MPI, prolonged resting QTd, and fixation of QTd during stress are independent predictors of significant CAD. In addition, resting QTd correlate with the Duke Jeopardy Score and therefore, may have independent prognostic value.     

Quantification of regional myocardial blood flow using first-pass multidetector-row computed tomography and adenosine triphosphate in coronary artery disease

BACKGROUND: The feasibility of using cardiac multidetector-row computed tomography (MDCT) technology in the quantitative assessment of myocardial blood flow (MBF) using the adenosine triphosphate (ATP) load technique was investigated in the present study. METHODS AND RESULTS: The study group comprised 14 patients (11 men, 3 women, age range 52-79 years, mean age 69.2 years) who underwent cardiac cine MDCT using the ATP-load technique. MBF was estimated from the slope of the linear regression equation with Patlak plots analysis. The overall average MBF was 1.83+/-0.62 ml . g(-1) . min(-1). Mean MBF in territories with stenosis on coronary angiography was 1.19+/-0.36 ml . g(-1) . min(-1) and 2.06+/-0.54 ml . g(-1) . min(-1) (p<0.01) in territories without stenosis. The average MBF in territories with moderate to severe ischemia on myocardial perfusion scintigraphy was 1.32+/-0.14 ml .g(-1 ). min(-1 )and 1.95+/-0.64 ml . g(-1) . min(-1) (p<0.01) in territories without ischemia. CONCLUSION: MDCT can be used to quantify MBF using first-pass dynamic data.     

Single-photon emission computed tomography myocardial perfusion imaging in patients with diabetes

Diabetes mellitus has reached epidemic proportions, creating a large population of people at increased risk for cardiac events. Single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI) provides an effective tool to accurately diagnose and risk stratify patients with diabetes, similar to patients without diabetes. Diabetics, however, are at increased risk for coronary events. Diabetics with normal MPI have increased late cardiac events, and even those with mild perfusion defects have increased event rates compared with nondiabetics with similar perfusion abnormalities. Stress MPI can provide valuable risk stratification data for both sexes, with or without diabetes. However, diabetes appears to exert a greater relative impact in women than in men. Despite the absence of symptoms, the incidence and prevalence of coronary artery disease is increased in patients with diabetes. Further studies and research will be needed to define the eventual role of SPECT MPI in asymptomatic diabetics.