CT coronary angiography (CTCA) has a negative predictive value of almost 100% for coronary artery disease and can therefore be used to screen for coronary lesions, thus avoiding unnecessary invasive coronary arteriography (CAG) examinations. This indication seems to overlap with nuclear myocardial perfusion imaging (MPI), which on the surface does not have a negative predictive value of 100%, and which is better, MPI or CTCA? Or are the advantages complementary? This is an issue of concern to the majority of clinicians, especially cardiovascular physicians. In recent years, cardiovascular imaging has become the fastest growing area of clinical progress in the cardiovascular discipline. At the 2008 European Society of Cardiology (ESC) annual meeting in Munich, cardiovascular imaging was the theme of the congress, with 73 sessions on cardiovascular imaging, covering the current status and future direction of research on the four major noninvasive imaging techniques: ultrasound, nuclear imaging, magnetic resonance imaging (MRI), and CT, which provide morphological, functional, and myocardial perfusion views of the heart and coronary arteries. These techniques provide detailed information on the morphology, function, and myocardial perfusion of the heart and coronary arteries, and greatly improve the diagnosis and treatment of cardiovascular diseases. Among the many imaging techniques, CTCA is undoubtedly the most advanced and the most rapidly used in clinical practice as a method for noninvasive visualization of coronary lesions and detection of subclinical atherosclerotic lesions, with a negative predictive value of almost 100% for coronary artery disease, and thus can be used for screening of coronary lesions, thus avoiding unnecessary invasive coronary arteriography (CAG). The value of clinical application. 1, the value of clinical application: The current clinical application of CTCA mainly includes two aspects: first, for patients with low or intermediate risk of coronary artery disease with symptoms or atypical symptoms, screening patients who need CAG examination by CTCA; second, in the emergency room for the identification of patients with chest pain, mainly for patients with low likelihood of acute coronary syndrome (ACS) (normal electrocardiogram, myocardial necrosis markers A negative result can help to exclude the diagnosis of ACS, thus shortening the hospital stay and reducing medical costs. In addition, CTCA can also be used to exclude coronary lesions or evaluate coronary malformations prior to cardiac valve surgery or non-cardiac surgery. Therefore, in patients with low- or intermediate-risk coronary artery disease, CTCA findings, especially negative findings, can aid in diagnosis and treatment, while in patients with positive findings, the presence of myocardial ischemia and precise evaluation of lesion morphology and extent remain important in the development of management plans. At present, the clinical and prognostic value of using CTCA to screen for coronary atherosclerotic lesions in asymptomatic individuals is still undetermined, and therefore CTCA is not recommended for use in routine physical examinations. 2. Limitations of clinical application Although technical advances in CTCA have made possible the noninvasive diagnosis of coronary lesions, the CTCA currently used still has the following limitations and is therefore not yet sufficient to replace CAG Although CTCA can reliably exclude coronary artery disease, it is still suboptimal in evaluating hemodynamic changes due to coronary lesions. MPI studies have shown that half of the lesions with >50% diameter stenosis shown by CTCA do not induce myocardial ischemia in the loading state. 2. The positive predictive value of CTCA examination is only about 80%, suggesting a relatively high rate of false positives. Heavy calcification severely hinders the reliability of CTCA in evaluating the degree of lesion stenosis, and arrhythmias (including premature beats and atrial fibrillation) occurring during the examination also affect the reliability of CTCA. Therefore, the imaging quality of the 64-row CTCA currently used is not sufficient to meet the reference needs of interventional cardiologists or cardiac surgeons to develop a hemodynamic reconstruction plan for patients, and most patients with positive CTCA findings still need to undergo CAG or other loading tests for inducing myocardial ischemia to further determine the treatment plan. 3. Those who undergo CTCA require higher doses of radiation and contrast, the former of which may have the potential risk of causing malignancy, while the latter may have an effect on renal function. CT technology is advancing very rapidly, and future CT technologies are expected to overcome these limitations. 256- and 320-row CTs are already in clinical trials, and new ECG triggering and image acquisition technologies are expected to significantly reduce radiation dose and allow the required data to be acquired in 1 or several cardiac cycles, allowing CTCA to be used in patients with irregular heart rhythms and even atrial fibrillation examination.