Diagnosis of Acute Aortic Syndromes Using Computed Tomography

Acute aortic syndrome refers to a group of life-threatening conditions characterized by acute injury to the aortic wall, primarily involving disruption of the intima and media. Acute aortic syndrome encompasses a spectrum of interrelated and overlapping clinical and morphological entities, including classic aortic dissection, intramural hematoma, penetrating aortic ulcer, and limited intimal tear. Differentiation of these variants based on clinical presentation and physical examination findings is not feasible. Imaging plays a pivotal role, and definitive diagnosis and classification of acute aortic syndrome variants are possible only through imaging studies. Multidetector computed tomography, transesophageal echocardiography, and magnetic resonance imaging are the primary imaging modalities used for the diagnosis of acute aortic syndrome, with contrast-enhanced multidetector computed tomography considered the gold standard. When classical imaging signs of a specific type of acute aortic syndrome are present, diagnosis is generally straightforward. However, a broad spectrum of imaging findings exists. In some cases, a single computed tomography scan may not allow for reliable differentiation among acute aortic syndrome variants. This limitation arises from the fact that these pathological entities may occur independently, progress from one to another, or coexist. The pathophysiology and clinical course of intramural hematoma and penetrating atherosclerotic ulcer of the aorta remain subjects of ongoing debate. In particular, the classification of intramural hematoma as a distinct acute aortic syndrome variant continues to be controversial. This article provides a concise overview of the current understanding of the pathophysiology, natural history, prognosis, and multidetector computed tomography-based diagnosis of the less common acute aortic syndrome variants, specifically intramural hematoma and penetrating atherosclerotic ulcer.