Differences in Aortic Intramural Hematoma Contrast Attenuation on Multi-Phase CTA Predict Long-Term Aortic...

Area of Science:

• Cardiovascular Imaging
• Radiology
• Vascular Surgery

Background:

• Aortic intramural hematoma (IMH) evolution is unpredictable, ranging from resolution to degeneration.
• Predicting IMH outcomes is crucial for patient management.
• Computed tomography angiography (CTA) offers insights into hematoma characteristics.

Purpose of the Study:

• To assess the Hounsfield unit ratio (HUR) on CTA as a predictor of IMH resolution and aortic growth.
• To correlate HUR with adverse aortic events.
• To establish HUR as a tool for guiding IMH surveillance and treatment strategies.

Main Methods:

• Retrospective analysis of IMH institutional data from 2005-2020.
• Measurement of HUR (delayed phase HU / arterial phase HU) on CTA.
• Linear mixed effects models to determine aortic growth and HUR effect.
• Kaplan-Meier analysis for freedom from adverse aortic events.

Main Results:

• HUR ranged from 0.38-1.92, with a mean of 0.98.
• An HUR > 1.15 correlated with aortic growth, while HUR < 1.15 indicated aortic diameter reduction.
• A trend was observed between higher HUR and composite adverse aortic events (HR 3.2).

Conclusions:

• Increased HUR is associated with aortic growth and a trend toward adverse events.
• Diminished delayed phase enhancement (lower HUR) may predict IMH resolution.
• HUR serves as a valuable metric for guiding IMH management.