Dynamic Imaging Features of Retrospective Cardiac Gating CT Angiography Influence Delayed Adverse Events in Acute Uncomplicated Type B Aortic Dissections

Purpose To investigate the correlation between dynamic morphological parameters of retrospective cardiac gating CT angiography (CTA) and delayed adverse event (DAE) in uncomplicated type B acute aortic dissection (uTB-AAD) patients. Materials and Methods Eighty-seven patients initially diagnosed with uTB-AAD were retrospectively reviewed. Dynamic variables obtained by dose-regulated retrospective CTA were recorded, including the minimum relative true lumen diameter (RTLA min ), ratio of the minimum to maximum true lumen relative area (r-RTLA), the maximum diameter of the descending aorta, false lumen, and primary entry tear. Outcome analysis comprised incidences of DAE and early mortality within 3 to 14 days since symptom occurring. Results Twenty-six patients (29.9%) developed DAE, and two of which (7.7%) died before any interventions. Smaller values of RTLA min ( P = 0.01) and r-RTLA at the upper thoracic descending aorta (UTDA) ( P < 0.001), and r-RTLA at the renal artery level ( P = 0.016) demonstrated higher incidences of DAE; maximum diameter of the descending aorta ( P < 0.001), the false lumen ( P = 0.008), and entry tear size ( P = 0.007) were positively associated with the occurrence of DAE. r-RTLA at the UTDA level yielded the highest diagnostic accuracy (82.0%) in detecting DAE at an optimal cutoff value of 61.7% (AUC = 0.839). Performance of dynamic characteristics was superior to static features obtained from single-phase image in the detection of DAE ( P < 0.001). Conclusion Dynamic morphological features of retrospective cardiac gating CTA might aid in identifying a high risk of DAE in uTB-AAD patients and guiding early targeted interventions.