Figure 1h. Normal anatomy of the heart, mediastinal vessels, and main bronchi at multidetector CT. (a) Thin-section axial image at the level of the ascending aorta (Ao) and pulmonary valve (PV) demonstrates normal anatomy of the left atrium (LA) and right atrium. The right atrial appendage (RAA) typically has a triangular shape, with a wider opening and larger pectinate muscles (arrows) than those of the left atrial appendage (LAA), which has a fingerlike shape. (b) Thin-section double-oblique image through the left ventricular inflow and outflow tract shows normal anatomy of the morphologic left ventricle with fine trabeculae, the anterolateral and posteromedial papillary muscles, and fibrous continuity (arrowhead) between the aortic valve (AV) and the mitral valve (MV). (c) Thin-section oblique sagittal image depicts the morphologic right ventricle (RV), which is characterized by coarse trabeculae and a muscular crest, the crista supraventricularis (arrowhead), between the tricuspid valve (TV) and the pulmonary valve (PV). (d) Thin-section oblique sagittal image shows the normal anatomy of the ascending aorta (aA), the aortic arch (AoA), the aortic isthmus (Isth), and the descending aorta (dA). The ascending aorta originates from the aortic valve (AV), between the left atrium (LA) and right atrium (RA). (e) Thin-section axial image demonstrates the pulmonary trunk (PT), the left pulmonary artery (lPA), and the right pulmonary artery (rPA). The left pulmonary artery is shorter than the right, and it courses in a more posterior direction. The right pulmonary artery passes behind the ascending aorta and the superior vena cava and in front of the descending aorta (dA). (f) Thin-section coronal image obtained with lung window settings shows a normal bronchial branching pattern. The right upper lobe bronchus (RULB) is superior to the right pulmonary artery (rPA), whereas the left pulmonary artery (lPA) courses over the left upper lobe bronchus (LULB). (g) Thick-section oblique coronal image obtained with a slab thickness of 5 mm demonstrates normal connections of the three systemic veins—the superior vena cava (SVC), inferior vena cava (IVC), and coronary sinus (CS)—to the right atrium (RA). The mixture of highly contrast-enhanced venous blood from the superior vena cava with nonenhanced venous blood from the inferior vena cava is visible in the atrium. LA = left atrium. (h) Volume-rendered image, obtained with reconstruction in an oblique right-posterior plane by using the cut-plane mode, demonstrates the relationship of the superior (SVC) and inferior (IVC) venae cavae to other anatomic structures adjacent to the site of venous connection to the right atrium (RA).