Isomerism in the setting of the so-called “heterotaxy”: The usefulness of computed tomographic analysis

Figure 1. Volume-rendered images viewed from the anterior direction. Fluoroscopy-like image (a) is combined with the trachea and bronchi (b). Bilateral diaphragms are located at the same height. Bilateral long bronchi with relatively sharp bronchial bifurcation angle are observed. Note the prominent azygos arch (arrows). Bilateral pulmonary arteries override the bilateral hyparterial long bronchi (c). Fluoroscopy-like image (a) is merged with the heart and bilateral bilobed lungs (d). Pulmonary morphology of the right (e) and left (f) lung show bilateral bilobed lungs

Figure 2. Multiplanar reconstruction images viewed from the inferior direction at the level of the inferior caval vein (a), oval fossa (b), aortic root (c), left atrial appendage (d), pulmonary bifurcation (e), and azygos continuation (yellow arrow) to the superior caval vein (f). Note the wide extent of the pectinate muscles in the morphologically right appendage (b and c), whereas the pectinate muscle is confined within the left atrial appendage (d)

Figure 3. Multiplanar reconstruction images viewed from the apical (left anterior oblique) direction at the level of the papillary muscle (a), tendinous chord (b), atrioventricular junction (c), coronary sinus (d), oval fossa (e), and azygos continuation (yellow arrows) to the superior caval vein (f). Note the wide extent of the pectinate muscles in the morphologically right appendage (d-f), whereas the pectinate muscle is confined within the left atrial appendage (b)

Figure 4. Volume-rendered dye-cast images of the entire heart viewed from the frontal (a), right anterior oblique (b), left anterior oblique cranial (c), posterior (d and e), and right posterior oblique directions (f). The difference in the external aspect between the wide right atrial appendage and small left atrial appendage is recognized. Bilateral pulmonary arteries override the bilateral hyparterial long bronchi (d-f). The azygos vein ascending along the right side of the descending aorta drains into the superior caval vein (e and f)

Figure 5. Volume-rendered virtual dissection images viewed from the base of the heart. The apex rotates leftward from the panel (a-c). Finger-like orifice of the left atrial appendage with smooth atrioventricular vestibule around the mitral valvar orifice is noted (a). On the contrary, in the right atrial appendage, the presence of pectinate muscles (red dotted curve) extending widely around the muscular atrioventricular vestibule of the tricuspid valvar orifice is noted (b and c)

Figure 6. Volume-rendered images of the body trunk viewed from the inferior direction. The horizontal plane-cut is made from the superior to inferior direction (a-f) to reveal the arrangement of the abdominal organs. Note the prominent azygos vein with interruption of the inferior caval vein, midline liver, multiple spleens, and left-sided gall bladder

Figure 7. Volume-rendered fluoroscopy-like image (a) is merged with the trachea and bronchi (b). Bilateral short bronchi with relatively wide bronchial bifurcation angle are observed. Note the abnormal tubular shadow (arrows), corresponding to the ascending vein of total anomalous pulmonary venous return. Bilateral pulmonary arteries do not override the bilateral eparterial short bronchi (c). Fluoroscopy-like image (a) is merged with the heart and bilateral trilobed lungs (d). Pulmonary morphology of the right (e) and left (f) lung show bilateral trilobed lungs

Figure 8. Multiplanar reconstruction images viewed from the inferior direction at the level of the inferior caval vein (a), ostium premium defect (b), superior margin of the common atrioventricular valve (c), bilateral infundibulums (d), arterial roots (e), and pulmonary bifurcation (f). Red star (b) remarks the solidified incomplete left ventricle located basal inferoanterior of the morphologically right ventricle. Black arrow (d) denotes the stenotic channel toward the subpulmonary infundibulum

Figure 9. Multiplanar reconstruction images viewed from the apical (right anterior oblique) direction at the level of the mid-ventricle (a), atrioventricular junction (b), bilateral morphologically right atrial appendage (c), mid-morphologically right atria (d), pulmonary bifurcation (e), and posterior morphologically right atria (f). Red star (b) remarks the solidified rudimentary chamber located basal infero-anterior of the morphologically right ventricle. Black arrow (b) denotes the stenotic channel toward the subpulmonary infundibulum

Figure 10. Volume-rendered dye-cast images viewed from the anterior (a), right anterior (b), right posterior (c), and posterior directions (d). Symmetrical external aspect of the bilateral morphologically right atrial appendages sandwiching the arterial roots (b) and the aspect of the total pulmonary venous return with ascending vein draining into the superior caval vein (d) are well recognized. Note the tortuous right coronary artery (e) and anterior interventricular coronary artery (f) delimiting the morphologically right ventricle from the solidified incomplete left ventricle (red stars)

Figure 11. Volume-rendered virtual dissection images viewed from the basal (a-c), apical (d), and right posterior oblique directions (e and f). The bilateral pectinate muscles (red dotted curves) extend widely around the common atrioventricular vestibule. The coarse trabeculation and double-outlet right ventricle are shown (e and f) with the septomarginal trabecula colored in green and solidified rudimentary chamber (red stars) colored in red (f). White arrows denote the string-like remnant of the primary atrial septum. Yellow arrows remark the stenotic channel of the subpulmonary infundibulum

Figure 12. Volume-rendered images of the body trunk viewed from the inferior direction. The horizontal plane-cut is made from the superior to inferior direction (a-f) to reveal the arrangement of the abdominal organs. Inferior caval vein, draining into the left-sided morphologically right atrium, is located left anterior to the descending aorta. Note the asplenia