CT and MR evaluation of pericardial and retrosternal adhesions after cardiac surgery

The visibility of the pericardium as well as of the space between the dorsal aspect of the sternal surface and the pericardial surface after cardiac surgery was determined by CT and/or MR with electrocardiographic (ECG)-gated spin-echo (SE) and gradient-echo sequences. Seventeen patients who had undergone cardiac operations and who were admitted for cardiac reoperation were investigated with CT and/or MR prior to sternal reentry. Five patients were investigated with CT alone, ten with both CT and MR, and two with MR only. At reoperation, retrosternal adhesions were classified as present or absent, and intrapericardial adhesions were classified as absent, minimal, moderate, or severe. A similar classification was applied to the CT and MR findings. In 14 of 15 patients, the CT findings were in agreement with those found at operation regarding postoperative retrosternal extrapericardial adhesions in the cranial retrosternal space and in 12 of 15 in the caudal retrosternal space. Computed tomography could not detect intrapericardial adhesions. Magnetic resonance was sensitive to metal artifacts from sternal sutures in both sequences and could therefore not be used to detect postoperative retrosternal extrapericardial adhesions. On the other hand, MR with ECG-gated SE sequences confirmed intrapericardial adhesions in 44 of 57 locations.