Accuracy of 64-slice CT angiography for the detection of functionally relevant coronary stenoses as assessed with myocardial perfusion SPECT

Purpose CT angiography (CTA) offers a valuable alternative for the diagnosis of CAD but its value in the detection of functionally relevant coronary stenoses remains uncertain. We prospectively compared the accuracy of 64-slice CTA with that of myocardial perfusion imaging (MPI) using ^99mTc-tetrofosmin-SPECT as the gold standard for the detection of functionally relevant coronary artery disease (CAD). Methods MPI and 64-slice CT were performed in 100 consecutive patients. CTA lesions were analysed quantitatively and area stenoses ≥50% and ≥75% were compared with the MPI findings. Results In 23 patients, MPI perfusion defects were found (12 reversible, 13 fixed). A total of 399 coronary arteries and 1,386 segments was analysed. Eighty-four segments (6.1%) in 23 coronary arteries (5.8%) of nine patients (9.0%) were excluded owing to insufficient image quality. In the remaining 1,302 segments, quantitative CTA revealed stenoses ≥50% in 57 of 376 coronary arteries (15.2%) and stenoses ≥75% in 32 (8.5%) coronary arteries. Using a cut-off at ≥75% area stenosis, CTA yielded the following sensitivity, specificity, negative (NPV) and positive predictive value (PPV), and accuracy for the detection of any (fixed and reversible) MPI defect: by patient, 75%, 90%, 93%, 68% and 87%, respectively; by artery, 76%, 95%, 99%, 50% and 94%, respectively. Conclusion Sixty-four-slice CTA is a reliable tool to rule out functionally relevant CAD in a non-selected population with an intermediate pretest likelihood of disease. However, an abnormal CTA is a poor predictor of ischaemia.     

电子束CT检出冠状动脉钙化及其与心肌灌注显像的对比研究

目的比较电子束ＣＴ（ＥＢＣＴ）检查冠状动脉钙化（ＣＡＣ）及核素心肌灌注显像（ＭＰＩ）评价冠心病（ＣＨＤ）的价值。材料与方法本组５０例均为临床疑诊或确诊为ＣＨＤ患者。所有患者均行ＥＢＣＴ、ＭＰＩ及冠状动脉造影。结果４０例患者共８４支血管冠状动脉造影证实有明显的冠状动脉病变（ＣＡＤ）（狭窄＞５０％），其中１４例为单支病变，８例为双支病变，１８例为三支病变，另有１０例冠状动脉造影正常。ＥＢＣＴ预测ＣＡＤ的敏感性、特异性及准确性为８３％、８０％及８２％，ＭＰＩ预测ＣＡＤ的敏感性、特异性及准确性分别为８５％、８０％及８４％，ＥＢＣＴ与ＭＰＩ的结果间无显著性差异（Ｐ＞０．０５）。ＣＡＣ血管供血区出现心肌缺血者达６５％。结论ＣＡＣ是预测ＣＡＤ的有价值指标。在有症状的人群中ＥＢＣＴ检出ＣＡＣ预测ＣＡＤ的敏感性、特异性及准确性与ＭＰＩ相似。有症状人群中检出ＣＡＣ患者多有心肌缺血或梗死，因此为早期诊断冠心病，应对无症状人群进行筛选。     

腺苷负荷心肌灌注显像对近期经皮冠状动脉介入治疗患者的临床价值

目的评估腺苷负荷心肌灌注显像（SMPI）在冠心病患者接受经皮冠状动脉介入治疗（PCI）后的临床价值。方法20例冠心病患者PCI前及后3d内各行1次腺苷SMPI。静息心肌灌注显像（RMPI）于PCI前SMPI的次日进行。心肌显像按17节段5分制进行评分。PCI后1年对患者进行电话随访（随访者不知晓患者的检查结果），在此期间发生心肌梗死或心因性死亡为严重心脏事件（HCE），PCI3个月后再次接受PCI或搭桥手术为非严重心脏事件（SCE）。率的比较行χ^2检验，频数比较行秩和检验。结果PCI前血管供血区域的可逆性节段，PCI后示90．9％（40／44）灌注有改善，不可逆缺损节段亦有41．3％（25／58）显示不同程度的改善。PCI后1年内出现1例HCE，5例SCE，预后与PCI前后受损节段灌注改善情况无关（χ^2=3．17，P〉0．05）。结论PCI后近期腺苷SMPI是评估PCI后心肌灌注的有效方法，其中可逆性缺损改善与否是评估PCI疗效的可靠指征；其预后价值有待进一步研究。     

Cardiac CT angiography (CTA) and nuclear myocardial perfusion imaging (MPI)-a comparison in detecting significant coronary artery disease

RATIONALE AND OBJECTIVES: Endowed with sufficient diagnostic accuracy, electron beam computed tomography angiography (CTA) is being increasingly used to evaluate coronary arteries. However, data on direct comparisons with nuclear myocardial perfusion studies are limited. In this study, we sought to compare the accuracies of CTA and myocardial perfusion imaging (MPI) for identifying symptomatic patients with hemodynamically significant obstructive coronary artery disease (CAD). MATERIALS AND METHODS: In a single-center study, symptomatic outpatients who were scheduled for cardiac catheterization were prospectively enrolled. Only patients with exertional angina or dyspnea were included. After fulfilling the inclusion criteria, 30 patients were enrolled in the study (mean age 54 +/- 9 years and 70% males). Patients underwent MPI, CTA including coronary artery calcification (CAC) measure, and invasive coronary angiography for evaluation of obstructive coronary artery disease. Significant CAD was defined as >50% left main artery stenosis or >70% stenosis of any other epicardial vessel by invasive angiography. The sensitivities, specificities and predictive values of MPI, CAC, and CTA were analyzed per patient RESULTS: CTA demonstrated significant higher sensitivity than MPI (95% vs. 81%, P < .05). CTA demonstrated significantly higher specificity than both MPI (89% versus 78%, P = .04) and CAC (56%, P = .002). CTA also performed better in a per-vessel analysis (sensitivity 94%, specificity 96%) than both nuclear and CAC. There were no significant differences between the sensitivities and specificities of MPI and CAC. CONCLUSION: CTA accurately detects obstructive CAD in symptomatic patients and may be more accurate than MPI or CAC assessment. Larger studies in a more diverse population are needed.     

可疑冠心病患者核素显像与CT冠状动脉造影对比分析

目的探讨核素心肌灌注显像（MPI）和CT冠状动脉造影（CTCA）2种无创性检查方法在可疑冠心病（CAD）患者诊断中的关系。方法对40例可疑冠心病患者行冠状动脉造影（CAG）、MPI和CTCA检查,均在2个月内进行。MPI结果分为正常和异常[可逆性和（或）不可逆性心肌缺血];CTCA结果分为正常、轻度（狭窄〈50％）和中度及其以上狭窄（至少1支主要血管或主要分支血管狭窄程度≥50％）。以CAG结果为“金标准”,对40例患者的MPI和CTCA结果进行对比分析。结果CTCA正常者中,90．1％的患者MPI正常;CTCA异常者中,55．2％的患者MPI正常;而MPI正常者中,61．5％的患者CTCA均有不同程度的狭窄。与CAG比较,CTCA的灵敏度、特异性和准确性高,分别为96．4％（27／28）、83．3％（10／12）和92．5％（37／40）。结论MPI和CTCA在可疑冠心病患者的诊断中提供了不同但却互补的信息,两者应合理联合应用。     

SPECT／CT显像评价“功能相关冠状动脉病变”的价值

目的探讨SPECT／CT显像评价“功能相关冠状动脉（简称冠脉）病变”的可行性及临床价值。方法40例可疑或确诊冠心病患者同机完成^99Tcm-甲氧基异丁基异腈（MIBI）负荷／静息心肌灌注断层显像和冠脉CT造影（CTCA）。负荷／静息心肌灌注显像采用标准二日法,首日行腺苷负荷心肌灌注显像,次日行静息心肌灌注显像及CTCA。腺苷按患者体质量以0．84mg·kg^-1·min^-1经静脉泵匀速给药,CTCA使用标准自动对比剂跟踪扫描程序完成。通过专用融合软件将心肌血流灌注与冠脉三维成像图融合,评价心肌缺血与冠脉病变的相关关系,确定“功能相关冠脉病变”。结果40例患者,CTCA正常20例,异常20例;120支冠脉中共检出33支病变血管,累及左前降支15支,左回旋支9支,右冠脉9支。心肌灌注显像正常22例,心肌缺血和（或）心肌梗死18例。SPECT心肌灌注和CTCA融合图像显示供血区心肌血流灌注正常且无狭窄冠脉占总的无狭窄冠脉的92．47％（86／93）,狭窄〈75％的冠脉中,其供血区心肌缺血或梗死的阳性率占42．86％（6／14,例）,狭窄〉75％或闭塞冠脉中,其供血区心肌缺血的阳性率占92．31％（12／13,例）。120支冠状动脉中20．83％（25／120,支）的病变冠脉为“功能相关冠脉病变”,检测出27例患者中25．93％（7／27,例）有无狭窄病变的冠脉导致心肌缺血;使15．38％（2／13,例）冠脉病变患者免除有创性诊断检查;指导对42．86％（6／14,例）的狭窄〈75％冠脉行药物治疗或冠脉血管重建术治疗;为1支狭窄〉75％的冠脉无需行血管重建术提供依据。结论SPECT／CT心肌灌注和CTCA融合显像可确定“功能相关冠脉病变”,可提供综合信息诊断冠心病和指导治疗。     

Adenosine stress rubidium-82 PET/computed tomography in patients with known and suspected coronary artery disease

BACKGROUND: Integrated positron emission tomography/computed tomography (PET/CT) is increasingly being utilized for myocardial perfusion imaging (MPI). However, there is a potential for increased imaging artifact compared with standard PET due to the different temporal resolution of PET and CT. We reviewed the diagnostic accuracy of adenosine stress Rb myocardial perfusion PET/CT to detect obstructive coronary artery disease (CAD) on invasive angiography at our institution. METHODS AND RESULTS: Seventy-five patients were included, 23 (13 men, mean age 55.8+/-11.8 years) with low likelihood of CAD and 52 (28 men, mean age 67.1+/-11.4 years) with intermediate to high pretest probability of disease. Coronary angiography was performed only in the latter 52 patients on average within 17 days of the MPI study. The test characteristics of PET/CT MPI were assessed using a threshold of >or=50 and >or=70% stenosis in one or more major coronary artery on invasive angiography. Dedicated software was used for registration, processing, and interpretation. Consensus interpretation of the tomographic PET slices using a 4-point scale (1=definitely normal, 2=probably normal, 3=probably abnormal, 4=definitely abnormal) was done by two readers blinded to clinical information. RESULTS: All MPI studies in the 23 low likelihood patients were normal. In the remaining 52 patients using a stenosis severity>or=50%, global sensitivity and specificity, negative and positive predictive value for detection of CAD were 86, 100, 57, and 100%. Using a stenosis severity>or=70%, these values changed to 90, 83, 71, and 87%. CONCLUSION: Adenosine stress Rb MPI using PET/CT with manual registration demonstrates diagnostic accuracy comparable with that of traditional PET MPI.     

Accuracy of stress Tc-99m tetrofosmin myocardial perfusion tomography for the diagnosis and localization of coronary artery disease in women

Background  Earlier studies have suggested a modest accuracy of stress thallium 201 myocardial perfusion imaging (MPI) for the diagnosis of coronary artery disease (CAD) in women. The accuracy of stress MPI with technetium 99m tetrofosmin has not been studied in women. The aim of this study was to assess the accuracy of stress Tc-99m tetrofosmin MPI for the diagnosis and localization of CAD in women. Methods and Results  We studied 88 women who underwent exercise or dobutamine stress Tc-99m tetrofosmin tomography and coronary angiography within 3 months. Significant CAD was defined as a stenosis 50% or greater in diameter in at least 1 major epicardial coronary artery. Myocardial perfusion abnormalities were detected in 44 of 53 patients with significant CAD and in 7 of 35 patients without significant CAD (overall sensitivity, 83% [95% confidence interval (CI), 73%-93%]; specificity, 80% [95% CI, 67%-93%]; and accuracy, 82% [95% CI, 74%-90%]). The sensitivity was 72% (18/25) in patients with single-vessel CAD and 93% (26/28) in patients with multivessel CAD. Perfusion abnormalities were detected in 2 or more vascular distributions in 20 of 28 patients with multivessel CAD and in 4 of 60 patients without multivessel CAD (sensitivity for the identification of multivessel CAD, 71% [95% CI, 55%-88%]; specificity, 93% [95% CI, 86%-98%]; and accuracy, 86% [95% CI, 79%-93%]). The sensitivity, specificity, and accuracy were 82%, 84%, and 83%, respectively, for the diagnosis of CAD in the left anterior descending artery; 77%, 84%, and 81%, respectively, for CAD in the right coronary artery; and 74%, 80%, and 78%, respectively, for CAD in the left circumflex artery. Conclusion  Stress Tc-99m tetrofosmin MPI is an accurate noninvasive technique for the diagnosis and localization of CAD in women. Supported in part by a publication grant from GE Healthcare     

腺苷负荷13N-NH3 PET心肌灌注显像结合冠状动脉CTA诊断冠心病

目的 评价腺苷负荷13N-NH3PET心肌灌注显像(MPI)与CT冠状动脉造影(CTA)相结合对提高冠心病(CAD)诊断准确性的临床应用价值.方法 对25例怀疑CAD的患者同时行腺苷负荷13N-NH3MPI及CTA,1个月内行导管法冠状动脉造影(CAG).结果 (1)25例患者共300个冠状动脉节段,CTA显示良好节段为263个,显示率(显示良好节段所占百分比)达87.7%.(2)25例患者CTA、MPI及CTA+MPI诊断CAD的灵敏度、特异性、准确性、阳性预测值及阴性预测值分别为82.1%(23/28),87.5%(14/16)及93.8%(15/16);93.2%(219/235),8/9及9/9;92.O%(242/263),88.0%(22/25)及96.0%(24/25);58.9%(23/29),93.3%(14/15)及100.0%(15/15);97.8%(219/224),8/10及9/10.结论 PET/CT实现了同机腺苷负荷"N-NH3PET心肌灌注显像与CTA相结合,提高了诊断CAD的准确性.     

Sensitivity,specificity and accuracy of stress SPECT myocardial perfusion imaging for detection of coronary artery disease in the distribution of first-order branch vessels,using an anatomical matching of angiographic and perfusion data

We sought to investigate the utility of stress single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) for the identification of coronary artery disease (CAD) in the distribution of first-order branch vessels. We evaluated 135 consecutive patients with coronary angiography and stress SPECT MPI. We anatomically matched angiography and SPECT to assess the sensitivity, specificity and accuracy of SPECT MPI for the detection of CAD in the distribution of first-order branches. Subgroup analysis for stress test performance and previous coronary artery bypass grafting (CABG) was also performed. The sensitivity, specificity and accuracy of stress SPECT MPI for the detection of CAD in the distribution of first-order branch vessels were all 67%. For isolated branch vessel CAD, stress SPECT MPI had a sensitivity of 44%. In patients without CABG, the sensitivity, specificity and accuracy for the detection of CAD in the distribution of first-order branch vessels were 71%, 67% and 68%, compared with 60%, 67% and 64% for patients with CABG. The sensitivity for isolated branch vessel CAD was 50% for patients without CABG, but only 29% for patients with CABG. The sensitivity and specificity for CAD in the distribution of branch vessels were similar for all patients for all stress test modalities and heart rate response (sensitivity, 64-69%; specificity, 61-69%). Stress SPECT MPI offers intermediate sensitivity, specificity and accuracy for the detection of CAD in the distribution of first-order coronary artery branch vessels. However, for isolated branch vessel CAD, stress SPECT has a lower sensitivity, particularly in patients with previous CABG.     

Clinical significance of myocardial perfusion abnormalities in patients with varying degree of coronary artery stenosis

OBJECTIVES: (1) To identify myocardial perfusion abnormalities in a cohort of patients having coronary artery disease (CAD) risk factors, with either suspected or clinical evidence of ischaemic heart disease (IHD), and with varying degree of coronary artery stenosis. (2) To evaluate the clinical significance of the extent and severity of perfusion abnormalities assessed by myocardial perfusion scintigraphy (MPS) in relation to the anatomical location of coronary stenosis demonstrated by five-vessel selective coronary angiography (SCA). METHODS: One hundred and thirty-eight patients (106 male, 32 female) with suspected or clinical evidence of IHD underwent diagnostic evaluation at the Central Hospital of Nicosia, between November 2002 and August 2003. The diagnostic work-up included clinical examination, exercise tolerance test, SCA and myocardial perfusion scintigraphy (MPS) using either Tl chloride or Tc-tetrofosmin. RESULTS: Based on the results of SCA, patients were divided into five groups on the basis of stenosis as cross-sectional area of coronary artery lumen and its haemodynamic significance, ranging from group 1=less than 50% coronary stenosis to group 5=100% stenosis (occlusion). Nine of 11 (40.9%) patients with angiographically normal coronary arteries (group 1) had moderate inducible reversible ischaemia on MPS and 9/47 (19.1%) patients with insignificant coronary stenosis (less than 75% stenosis=group 2) had fixed perfusion defects, compatible with previous myocardial infarction. The extent of perfusion abnormalities in post-stress MPS patients from group 2 was not found to be statistically significant (P>0.05) when compared to patients belonging to groups 3, 4 and 5. However, the extent of perfusion abnormalities between patients from group 2, when compared to groups 3, 4 and 5 demonstrated significant statistical difference (P<0.05) on post-rest MPS studies. Furthermore, there was no significant statistical correlation between anatomical location of coronary stenosis and severity of perfusion abnormalities in the corresponding myocardial segments. CONCLUSION: Patients with CAD risk factors, and coronary arteries with insignificant stenosis on angiography, may demonstrate inducible reversible myocardial ischaemia. This is suggestive of coronary endothelial dysfunction. Patients with insignificant coronary artery stenosis and no previous history of adverse coronary events may demonstrate features of previous myocardial infarction on MPS. The severity of perfusion defects demonstrated by MPS may be independent of the anatomical location of coronary artery stenosis.     

Combined functional and morphological imaging consisting of gated myocardial perfusion SPECT and 16-detector multislice spiral CT angiography in the noninvasive evaluation of coronary artery disease: first experiences

INTRODUCTION: Appropriate diagnosis and therapy of coronary artery disease (CAD) frequently require information about both the functional and morphological status of the coronary artery tree. We hypothesized that the combination of multislice spiral CT (MDCT) angiography and myocardial perfusion SPECT (MPI) provides accurate allocation of perfusion defects (PD) to their determining coronary lesion. METHODS: Twenty patients (14 male, mean age 64+/-9.2 years) with known CAD were retrospectively studied. Gated MPI, CT angiography using a 16-detector CT scanner, and conventional coronary angiography (CCA) were performed in each patient. Reversible and fixed PD were subsequently allocated to their determining lesion separately by different observers for MDCT angiography and CCA. RESULTS: All patients showed significant CAD in CCA; six patients with one-, six with two-, six with three-, and two with four-vessel disease; three patients had bypass grafts; and five patients had prior myocardial infarction. Correct diagnosis of CAD was stated in 14 of 20 patients by MDCT angiography. Five reversible and five fixed PD were detected in 9 of 20 patients; one patient showed both reversible and fixed PD. Five of five reversible PD could be allocated to appropriate coronary artery stenoses in CCA. In MDCT angiography, five of five reversible PD were allocated to the same lesions; all lesions were rated as >/=50%. CONCLUSIONS: The preliminary results of the present study show high accuracy for multislice spiral CT angiography to allocate reversible perfusion defects in myocardial scintigraphy to their determining coronary artery lesions in a small patient collective with known coronary artery disease.     

Automated quantitative Rb-82 3D PET/CT myocardial perfusion imaging: Normal limits and correlation with invasive coronary angiography

Background

We aimed to characterize normal limits and to determine the diagnostic accuracy for an automated quantification of 3D 82-Rubidium (Rb-82) PET/CT myocardial perfusion imaging (MPI).

Methods

We studied 125 consecutive patients undergoing Rb-82 PET/CT MPI, including patients with suspected coronary artery disease (CAD) and invasive coronary angiography, and 42 patients with a low likelihood (LLk) of CAD. Normal limits for perfusion and function were derived from LLk patients. QPET software was used to quantify perfusion abnormality at rest and stress expressed as total perfusion deficit (TPD).

Results

Relative perfusion databases did not differ in any of the 17 segments between males and females. The areas under the receiver operating characteristic curve for detection of CAD were 0.86 for identification of ??50% and ??70% stenosis. The sensitivity/specificity was 86%/86% for detecting ??50% stenosis and 93%/77% for ??70% stenosis, respectively. In regard to normal limits, mean rest and stress left ventricular ejection fraction (LVEF) were 67%?±?10% and 75%?±?9%, respectively. Mean transient ischemic dilation ratio was 1.06?±?0.14 and mean increase in LVEF with stress was 7.4%?±?6.1% (95th percentile of 0%).

Conclusion

Normal limits have been established for 3D Rb-82 PET/CT analysis with QPET software. Fully automated quantification of myocardial perfusion PET data shows high diagnostic accuracy for detecting obstructive CAD.     

Integrated assessment of coronary anatomy and myocardial perfusion using a retractable SPECT camera combined with 64-slice CT: initial experience

We evaluated a prototype SPECT system integrated with multidetector row CT (MDCT) for obtaining complementary information on coronary anatomy and hemodynamic lesion significance. Twenty-five consecutive patients with known or suspected coronary artery disease (CAD) underwent routine SPECT myocardial perfusion imaging (MPI). All patients also underwent repeat MPI with a mobile SPECT unit which could be attached to a 64-slice MDCT system. Coronary CT angiography (cCTA) was performed without repositioning the patient. Investigational MPI was compared with routine MPI for detection of myocardial perfusion defects (PD). Two observers diagnosed presence or absence of CAD based on MPI alone, cCTA alone, and based on combined MPI and cCTA with fused image display. In 22/24 patients investigative MPI corresponded with routine MPI (r = 0.80). Stenosis ≥ 50% at cCTA was detected in 6/24 patients. Six out of 24 patients had PD at regular MPI. Three of these six patients had no significant stenosis at cCTA. Three out of 19 patients with normal MPI studies had significant stenosis at cCTA. Our initial experience indicates that the integration of SPECT MPI with cCTA is technically feasible and enables the comprehensive evaluation of coronary artery anatomy and myocardial perfusion with a single instrumental setup. This study received research support from Siemens Medical Solutions (Malvern, Pa). UJS is a medical consultant to Bayer, Bracco, General Electric, Siemens, and TeraRecon and receives research support from Bayer, Bracco, General Electric, Medrad, and Siemens. LG is a medical consultant to Cytogen Corporation. PC is a medical consultant to Bracco and receives research support from Siemens.     

Accuracy of 99mTc-tetrofosmin myocardial tomography in the evaluation of coronary artery disease

BACKGROUND: Technetium 99m-labeled myocardial agents have been proposed as an alternative to thallium 201. The aim of this study was to assess retrospectively the accuracy of exercise myocardial 99mTc-tetrofosmin scintigraphy with tomographic imaging (SPECT) in a large group population in the evaluation of coronary artery disease. Furthermore we evaluated the relation between the severity of scintigraphic impaired myocardial perfusion and the angiographic coronary artery stenoses in patients without myocardial infarction and with stenosis localized exclusively in the proximal segment of the 3 main coronary arteries. METHODS AND RESULTS: The study group consisted of 235 consecutive patients, 204 (87%) of whom were men, with a mean age of 57+/-10 years, and with suspected or known coronary artery disease, who underwent 99mTc-tetrofosmin SPECT and coronary angiography. Furthermore, 61 patients in a low-likelihood group for coronary artery disease were also studied. Significant disease was defined by > or = 50% luminal coronary artery stenosis in > or = 1 native coronary artery or major branch or in a saphenous vein graft or arterial mammary graft. The overall sensitivity was 95%, specificity was 76%, and predictive accuracy was 95%. The normalcy rate for the low-likelihood group was 93%. Sensitivity was 71% for the left anterior descending artery, 61% for the left circumflex artery, and 73% for the right coronary artery. Specificity was 94% for the left anterior descending artery, 96% for the left circumflex artery, and 91% for the right coronary artery. Predictive accuracy was 79% for the left anterior descending artery, 78% for the left circumflex artery, and 81 % for the right coronary artery. In patients without myocardial infarction linear regression analysis between scintigraphy and angiography showed a significant correlation in patients with severe proximal coronary artery stenosis (r = 0.53, P < .002), but not in those with moderate proximal stenosis (r = 0.31, P = NS). CONCLUSIONS: This study shows that 99mTc-tetrofosmin SPECT is accurate in the detection of coronary artery disease. The relation of the severity of scintigraphic impaired myocardial perfusion and angiographic coronary artery stenosis, however, may differ significantly in patients with proximal stenosis of different severity.     

负荷心肌灌注显像与双源CT冠脉成像诊断冠心病的对比研究

目的:通过对心肌灌注显像(MPI)与心脏双源CT(DSCT)检查结果进行对比分析,探讨两者对冠心病的临床诊断价值.方法:对38例拟诊为冠心病的患者行MPI及心脏DSCT检查;分别对MPI图像及DSCT图像进行分析处理,其中29例经冠状动脉造影(CAG)证实为冠心病.结果:DSCT显示有29例冠脉狭窄程度＞50％,其中大...     

核素心肌灌注显像结合冠状动脉CT成像评价2型糖尿病功能相关冠状动脉病变的价值

目的 应用核素心肌灌注显像(MPI)结合冠状动脉CT成像(CTCA)评价2型糖尿病冠状动脉病变对心肌血供的影响,并与单一MPI或CTCA进行比较.资料与方法 纳入120例怀疑或确诊的冠状动脉粥样硬化性心脏病患者,根据其病史分为糖尿病组(n=58)和非糖尿病组(n=62),所有患者均行常规腺苷负荷/静息MPI和CTCA,并均于1个月内行冠状动脉血管造影术(CAG).以CAG、CAG联合MPI作为标准评价单一MPI、CTCA、MPI结合CTCA对“功能相关冠状动脉病变”的诊断效能.结果 糖尿病组MPI结合CTCA评价2型糖尿病冠状动脉病变与心肌血供关系的敏感性、特异性、准确性、阳性预测值和阴性预测值分别为93.58％、86.15％、90.80％、91.89％、88.89％.非糖尿病组MPI结合CTCA评价冠状动脉病变与心肌血供关系的敏感性、特异性、准确性、阳性预测值和阴性预测值分别为93.10％、91.43％、92.47％、94.74％、88.89％,均高于单一MPI或CTCA的诊断效能.结论 MPI结合CTCA评价2型塘尿病冠状动脉病变对心肌血供的影响,其诊断“功能相关冠状动脉病变”的效能明显高于单一影像技术.     

Myocardial damage size assessment in the zone of infarction for indicating rescue percutaneous coronary intervention

BACKGROUND: The most important predictors of subsequent patients outcome after acute myocardial infarction (AIM) are infarct size, left ventricular ejection fraction, left ventricular volumes and presence and extent of residual myocardial ischemia. All of these variables can be directly determined through scintigraphic approaches. The presence and extent of myocardial ischemia are strong pre dictors for fatal and nonfatal cardiac events and improve risk statification beyound the information gleaned from clinical variables. CASE REPORT: We presented a case of 66-years-old male with myocardial infarction of anteroseptal localization. Myocardial perfusion imaging (MPI) detected a large zone of residual ischemia (culprit lesion) within infarction zone. It has an important role in risk stratification after myocardial infarction, and indicates subsequent therapeutic decision making, in this case rescue percutaneous coronary intervention (PCI). After PCI we followed the therapy effect by MPI, and we found practically normal perfusion with minimal zone of defect perfusion in the apex. CONCLUSION: Myocardial perfusion imaging has an important role in the initial evaluation and risk stratification of patients surviving myocardial infarction. It also plays a major role in guiding subsequent therapeutic decision making, and in monitoring the benefits of these therapeutic measures.     

64-slice CT angiography for the detection of functionally significant coronary stenoses: comparison with stress myocardial perfusion imaging

Objective

To evaluate the accuracy of 64-slice CT angiography (CTA) compared with single photon emission CT (SPECT) myocardial perfusion imaging (MPI), which served as the reference standard, for the detection of functionally significant coronary artery disease (CAD).

Methods

141 consecutive patients (60±10 years, 101 men) were investigated with 64-slice CTA and SPECT MPI; a subset of 35 patients had additional invasive coronary angiography (ICA). The data from CTA and ICA were compared with those from MPI for both cut-offs of ≥50% and ≥70% stenosis, respectively.

Results

The sensitivity, specificity, positive and negative predictive values, and accuracy of CTA, using a cut-off of ≥50% for significant stenosis, in detecting inducible perfusion defects on MPI were 96% [95% confidence interval (CI) 88–100%], 61% (95% CI 52–70%), 37% (95% CI 23–49%), 99% (95% CI 97–100%) and 68%, respectively, in patient-based analysis and 97% (95% CI 91–100%), 86% (95% CI 83–89%), 33% (95% CI 24–42%), 100% (95% CI 99–100%) and 87%, respectively, in vessel-based analysis. Applying a cut-off of ≥70% for significant stenosis, CTA yielded the following sensitivity, specificity, positive and negative predictive values, and accuracy for the detection of inducible MPI defects: by patient, 65% (95% CI 46–84%), 95% (95% CI 91–99%), 74% (95% CI 50–92%), 92% (95% CI 87–97%) and 89%, respectively; by vessel, 58% (95% CI 42–74%), 97% (95% CI 95–99%), 62% (95% CI 45–79%), 97% (95% CI 95–99%) and 95%, respectively.

Conclusion

64-slice CTA is a reliable tool to exclude functionally significant CAD when using a cut-off of ≥50% diameter stenosis. By contrast, a cut-off of ≥70% diameter narrowing is a strong predictor of ischaemia.In recent years, multislice coronary CT angiography (CTA), with improved spatial and temporal resolution, has been consistently shown to have a very high negative predictive value (NPV) for the diagnosis of coronary artery disease (CAD) [1-4]. With NPVs approaching nearly 100%, the technique has also been promoted as a particularly effective tool for excluding the presence of significant CAD. Therefore, patients with normal coronary arteries on multislice CTA may be reassured and generally do not require further testing. Nevertheless, in many instances multislice CTA will unexpectedly reveal the presence of atherosclerotic lesions, as the technique identifies both early subclinical and more advanced CAD. Intuitively, this non-invasive identification of atherosclerosis may have advantages for patient management, as it provides an opportunity for targeted and more individualised antiatherosclerotic treatment. However, management decisions such as referral for revascularisation remain largely dependent on the severity of symptoms in combination with the extent of ischaemia demonstrated during functional testing. Unfortunately, this important information is currently not obtained from multislice CTA, and the diagnostic value of CTA in the detection of functionally significant coronary artery lesions as defined by reversible or fixed perfusion defects on myocardial perfusion imaging (MPI) remains uncertain as only limited data are available on this specific issue [5-11].Stress MPI using single photon emission CT (SPECT) is a well-established method for the non-invasive detection of CAD [12]. Besides its diagnostic accuracy, SPECT MPI allows evaluation of the functional severity of coronary stenoses and provides valuable information for cardiac risk assessment, which will facilitate clinical decision-making and may help avoid unnecessary invasive coronary angiography or intervention [13-16]. By contrast, the purely anatomical delineation depicted by invasive and non-invasive angiography offers limited functional and prognostic information [17-19]. In fact, SPECT MPI now forms a strong symbiotic relationship with coronary angiography, which can guide therapy.With increasing use of multislice CTA, clinicians will be more frequently confronted with patients having confirmed atherosclerotic coronary lesions but yet of uncertain haemodynamic relevance. Therefore, the aim of this retrospective study was to evaluate the accuracy of 64-slice CTA compared with SPECT MPI, which served as the reference standard, for the detection of functionally significant coronary lesions. In addition, the non-invasive imaging findings were compared with invasive coronary angiography (ICA) in a subset of patients.     

Low-dose CT coronary angiography for the prediction of myocardial ischaemia

The purpose of this study was to prospectively determine the accuracy of low-dose computed tomography coronary angiography (CTCA) for the diagnosis of functionally relevant coronary artery disease (CAD) using cardiac magnetic resonance (CMR) as a standard of reference. Forty-one consecutive patients (age 64?±?10 years) underwent k-space and time broad-use linear acquisition speed-up technique accelerated CMR (1.5 T) and dual-source CTCA using prospective electrocardiography gating within 1 day. CTCA lesions were analysed and diameter stenoses of more than 50% and more than 75% were compared with CMR findings taken as the reference standard for assessing the functional relevance of CAD. CMR revealed perfusion defects in 21/41 patients (51%). A total of 569 coronary segments were analysed with low-dose CTCA. The image quality of low-dose CTCA was diagnostic in 566/569 segments (99.5%) in 39/41 patients (95%). Low-dose CTCA revealed stenoses of more than 50% in 58/123 coronary arteries (47.2%) in 24/41 patients (59%) and more than 75% stenoses in 46/123 coronary arteries (37.4%) in 23/41 patients (56%). Using a greater than 50% diameter stenosis, low-dose CTCA yielded the following per artery sensitivity, specificity, positive and negative predictive values, and accuracy for the detection of perfusion defects: 89%, 79%, 72%, 92% and 83%, respectively. Low-dose CTCA is reliable for ruling out functionally relevant CAD, but is a poor predictor of myocardial ischaemia.