FIGURE 2 Computed tomography (CT) images of LA, esophagus, and periesophageal structures. Panel A and panel B were axial CT images at the CPL level. Panel A, the esophagus was close to LIPV; Panel B, the esophagus was close to RIPV. No fat pad between LAPW and esophagus was identified on both panel A and panel B. The esophagus was not enclosed by the vertebral body, descending aorta and LAPW on both panel A and panel B; Panel C, a fat pad (red arrow) between LAPW and esophagus was identified at the MPL level. Panel D, sagittal CT image of LA and esophagus, a fat pad (red arrow) was identified at an inferior level (MPL level), while no fat pad was identified at CPL level (black arrow). DA, descending aorta, E, esophagus, LA, left atrium; CPL, conventional posterior line; MPL, modified posterior-inferior line; LIPV, left inferior pulmonary vein; RIPV, right inferior pulmonary vein; VB, vertebral body; LAPW, left atrial posterior wall.