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Expert opinion: How and when to perform CT myocardial perfusion imaging.

The heart rates of patients with acute chest pain presenting in the ED are high and CCTA images are often nondiagnostic. Therefore, CT myocardial perfusion (CTP) imaging can help exclude myocardial ischemia in this situation. Other scenarios may include patients with heavy calcifications or stents. Ostial stenosis or branch vessel obstruction can be easily overlooked by radiologists. As myocardial perfusion status is the most critical information for treatment decisions, CTP should be performed when it is deemed necessary and available. CTP may be recommended for ED patients when they have heavy calcifications in the proximal coronary arteries on calcium score CT or stents. When initial CCTA shows suboptimal image quality, CTP in either a dynamic or static low-radiation protocol can be adopted.