Standardized myocardial segmentation and nomenclature for tomographic imaging of the heart: A statement for healthcare professionals from the Cardiac Imaging Committee of the Council on Clinical Cardiology of the American Heart Association***

Nuclear cardiology, echocardiography, cardiovascular magnetic resonance (CMR), cardiac computed tomography (CT), positron emission computed tomography (PET), and coronary angiography are imaging modalities that have been used to measure myocardial perfusion, left ventricular function, and coronary anatomy for clinical management and research. Although there are technical differences between these modalities, all of them image the myocardium and the adjacent cavity. However, the orientation of the heart, angle selection for cardiac planes, number of segments, slice display and thickness, nomenclature for segments, and assignment of segments to coronary arterial territories have evolved independently within each field. This evolution has been based on the inherent strengths and weaknesses of the technique and the practical clinical application of these modalities as they are used for patient management. This independent evolution has resulted in a lack of standardization and has made accurate intra- and cross-modality comparisons for clinical patient management and research very difficult, if not, at times, impossible. Attempts to standardize these options for all cardiac imaging modalities should be based on the sound principles that have evolved from cardiac anatomy and clinical needs.1–3⇓⇓ Selection of standardized methods must be based on the following criteria: An earlier special report from the American Heart Association, American College of Cardiology, and Society of Nuclear Medicine4 defined standards for plane selection and display orientation for serial …