Gupta Mohit, Kadakia Jigar, Jug Borut, Mao Song Shou, Budoff Matthew J
Harbor UCLA Medical Center, Division of Cardiology, Los Angeles Biomedical Research Institute, Torrance, California 90502, USA.
Coron Artery Dis. 2013 Jun;24(4):290-7. doi: 10.1097/MCA.0b013e32835f2fe5.
Hypoenhanced regions on cardiac computed tomography angiography (CCTA) correlate with myocardial hypoperfusion. We evaluated the ability of resting single-phase 64-slice CCTA to detect the presence of myocardial infarction (MI) compared with nuclear myocardial perfusion imaging (MPI).
One hundred and forty symptomatic patients (age 66±12 years, 64% men) with an irreversible perfusion defect (n=69) or a normal/reversible perfusion defect (n=71) on MPI were subjected to CCTA for further evaluation. MI on CCTA was detected visually on the basis of areas of hypoattenuation (dark) in the myocardium and the corresponding Hounsfield Units (HU) were measured.
CCTA accurately detected MI in 62 patients with an irreversible perfusion defect on MPI, yielding a sensitivity of 90%, a specificity of 94%, a negative predictive value of 91%, and a positive predictive value of 94%. The mean HU of normal and infarcted left ventricular myocardium was 107±23 and 16±40, respectively (P<0.001). An HU cut-off of 28 detected the presence of myocardial scar with 86% sensitivity and 59% specificity. The infarct volume measured by CCTA correlated well with the summed rest score (r=0.567; P<0.001) and the summed stress score (r=0.489; P<0.001) on MPI. In a substudy of 50 patients, the GE perfusion tool yielded a sensitivity of 92%, a specificity of 73%, an negative predictive value of 91%, and a positive predictive value of 76% in detecting MI.
Resting single-phase CCTA is highly accurate in detecting and quantifying MI. This study highlights a novel clinical utility of CCTA in addition to assessment of plaque burden and stenosis with no risk of additional radiation or contrast exposure to the patient.
心脏计算机断层扫描血管造影（CCTA）上的低增强区域与心肌灌注不足相关。我们评估了静息单相64层CCTA与核素心肌灌注显像（MPI）相比检测心肌梗死（MI）的能力。
140例有症状患者（年龄66±12岁，64%为男性），MPI显示为不可逆灌注缺损（n = 69）或正常/可逆灌注缺损（n = 71），接受CCTA进一步评估。基于心肌内低密度（暗区）区域通过视觉检测CCTA上的MI，并测量相应的亨氏单位（HU）。
CCTA准确检测出62例MPI显示不可逆灌注缺损患者的MI，敏感性为90%，特异性为94%，阴性预测值为91%，阳性预测值为94%。正常和梗死左心室心肌的平均HU分别为107±23和16±40（P<0.001）。HU截断值为28时，检测心肌瘢痕的敏感性为86%，特异性为59%。CCTA测量的梗死体积与MPI上的静息总分（r = 0.567；P<0.001）和负荷总分（r = 0.489；P<0.001）相关性良好。在一项50例患者的子研究中，GE灌注工具检测MI的敏感性为92%，特异性为73%，阴性预测值为91%，阳性预测值为76%。
静息单相CCTA在检测和量化MI方面高度准确。本研究突出了CCTA除评估斑块负荷和狭窄外的一种新的临床应用，且不会给患者带来额外辐射或造影剂暴露风险。
