The dynamics of an ascending aorta dissection by 16 row multislice computed tomography
A 65 year old man was referred for follow up of a dissected ascending aorta. The study was performed with a 16 slice spiral computed tomography scanner (Sensation 16, Siemens, Germany) after the intravenous administration of 100 ml of iodinated contrast material with the following protocol: detector collimation 12 × 1.5 mm, rotation time 0.42 s, scan time 19 s. The scan was retrospectively reconstructed using the ECG track to create iso-cardio-phasic datasets. Main datasets were reconstructed in the diastolic phase and systolic phase (80% and 20% of the RR interval, respectively). The false lumen, in the diastolic phase, occupies almost the entire volume of the ascending aorta (below, panel A). The dynamics of the dissected flap are shown during the diastolic and systolic phase of the cardiac cycle (right, panels A–F). During the diastolic (A, C, E) phase the true lumen collapses while the false lumen is widely expanded. This configuration is caused by the higher blood pressure in the false lumen during diastole, which compresses the true lumen. In the systolic phase (B, D, F) the true lumen is maximally expanded because of the high systolic pressure during the ventricular systolic ejection phase.
The patient did not undergo surgery because of the severely impaired heart function.