rss
Heart 89:970 doi:10.1136/heart.89.9.970
  • Miscellanea

The dynamics of an ascending aorta dissection by 16 row multislice computed tomography

  1. F Cademartiri,
  2. K Nieman,
  3. N R Mollet
  1. filippocademartiri{at}hotmail.com

    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.


    Graphic

    Comparison between diastolic (left column— A, C, E) and systolic (right column—B, D, F) configuration of the dissected flap. The axial slices performed at the level of the right pulmonary artery (A, B) and at the level of the origin of the left coronary artery (C, D) show how the dissected flap shifts between the diastolic and systolic phase. The sagittal oblique multiplanar reconstructed images (E, F), display the same behaviour of the flap (white arrowheads) along the ascending aorta. During the diastolic phase the dissected flap tends to cover the origin of the left coronary artery. Also clearly displayed is the closed and open aortic valve during the diastolic and systolic phase, respectively (E and F). FL, false lumen; TL, true lumen; LV, left ventricle; RV, right ventricle; RVOT, right ventricular outflow tract; L, liver; LAD, left anterior descending; LCA, left coronary artery; LA, left atrium; AAo, ascending aorta; DAo, descending aorta; PA, pulmonary artery.


    Graphic

    Panoramic images reconstructed in the diastolic phase. The sagittal oblique multiplanar reformatted image (A) and the three dimensional volume rendering reconstruction (B), show the configuration of the dissected flap. The false lumen in the ascending tract of the thoracic aorta occupies most of the transverse diameter of the vessel at this level.