Modern imaging techniques: applications in the management of acute aortic pathologies

Abstract

Acute aortic pathologies include traumatic and nontraumatic life-threatening emergencies of the aorta. Since the clinical manifestation of these entities can be non-specific and may overlap with other conditions presenting with chest pain, non-invasive imaging plays a crucial role in their rapid and accurate evaluation. The early diagnosis and accurate radiological assessment of acute aortic diseases is essential for improved clinical outcomes. Multidetector CT is the imaging modality of choice for evaluation of acute aortic diseases with MRI playing more of a problem-solving role. The management can be medical, endovascular or surgical depending upon pathology, and imaging remains an indispensable management-guiding tool. It is important to understand the pathogenesis, natural history, and imaging principles of acute aortic diseases for appropriate use of advanced imaging modalities. This understanding helps to formulate a more appropriate management and follow-up plan for optimised care of these patients. Imaging reporting pearls for day-to-day radiology as well as treatment options based on latest multidisciplinary guidelines are discussed. With newer techniques of image acquisition and processing, we are hopeful that imaging would further help in predicting aortic disease progression and assessing the haemodynamic parameters based on which decisions on management can be made.

Imaging of the aortic root on high-pitch non-gated and ECG-gated CT: awareness is the key!

“…The accuracy and hence use of CTA for other vascular applications like coronary artery imaging is also expanding [11]. CT is fast, noninvasive, widely available, and allows evaluation of entire aorta with very high (nearly 100%) sensitivity and specificity for the diagnosis of aortic pathologies [2,4,12]. CT imaging of the proximal aorta requires appropriate timing for peak aortic contrast enhancement and conventionally needs ECG gating to prevent artifacts from transmission of cardiac pulsations.…”

“…These techniques allow reproducible aortic measurements at specific anatomic landmarks. The maximum diameter of the SOV is measured in short axis from the sinus-to-trigon, and the ascending aorta is typically measured at the level of the right pulmonary artery [2,15]. Since the treatment and follow-up of many aortic pathologies are based on size cutoff, a standardized methodology is very important (class A recommendation) [13].…”

“…The diseases of the aorta are life threatening and are being increasingly diagnosed due to increased use and availability of imaging [1]. Epidemiologically, the incidence of the most life-threatening aortic disorder, aortic dissection (AD), has increased over time, which could be due to better detection with improved imaging or increased longevity [1,2]. More importantly, the advances in imaging technology have facilitated the assessment of cardiac structures and proximal aorta on "routine" nonelectrocardiogram (ECG)-gated chest CTs.…”

“…Moreover, improved visualization of the proximal aorta on scans obtained on scanners with faster gantry rotation and their interpretation by radiologists that may not be familiar with these diseases has added to this challenge. Although technological advances have happened in other aortic imaging modalities like magnetic resonance angiography, and trans-esophageal echocardiography [2], incidentally seen aortic pathologies are mostly described with CT. Hence, we aim to present a review of proximal aortic anatomy, various disorders that affect the aortic root, and their imaging appearances to familiarize radiologists with the diseases of this location.…”

Advances in the diagnosis of acute aortic syndromes: Role of imaging techniques

“…CT image acquisition for aortic diseases should start at least 3 cm above the aortic arch and extend caudally to the femoral head to ensure that all aortic segments are evaluated. 31 MD-CT provides images of the entire aorta during the arterial transit of contrast bolus; 16-, 64-and even 256-slice CT scanners have replaced invasive techniques such as angiography to study medium and large vessels of the chest and abdomen. 10 A new technique involves the acquisition of electrocardiographic (ECG)-gated CT images, which allow more accurate measurements of aortic annulus, sinuses of Valsalva and proximal ascending aorta, eliminating artefacts related to the cardiac motion.…”