HELICAL (SPIRAL) CT IN THE EVALUATION OF EMERGENT THORACIC AORTIC SYNDROMES: Traumatic Aortic Rupture, Aortic Aneurysm, Aortic Dissection, Intramural Hematoma, and Penetrating Atherosclerotic Ulcer - ScienceDirect

Radiologic Clinics of North America

Volume 37, Issue 3, 1 May 1999, Pages 575-589

Radiologic Clinics of North America

https://doi.org/10.1016/S0033-8389(05)70112-3 Get rights and content

Catheter angiography has traditionally been the gold standard for evaluating emergent aortic syndromes. With advances in MR imaging, color Doppler ultrasound (US), and CT, newer noninvasive ways of evaluating the thoracic and abdominal aorta have emerged. Although each of these modalities has its strengths and weaknesses, CT plays the dominant and critical role in the evaluation of patients presenting with emergent aortic syndromes. This article focuses on the use of helical CT in the evaluation of traumatic aortic rupture, thoracic aortic aneurysm, aortic dissection, intramural hematoma, and penetrating atherosclerotic ulcer. For each entity the pathophysiology, CT technique, and characteristic CT findings are discussed.

Section snippets

PRACTICAL IMAGING CONSIDERATIONS

Most emergency departments do not have immediate access to MR imaging scanners. MR imaging examination times are longer than with CT, and potentially unstable patients are more difficult to monitor. Additionally, MR imaging examinations cost more and are more operator-dependent than CT.⁸⁶ Both MR imaging and US are favorable in that they lack ionizing radiation. US has the additional advantage of portability, which makes it readily available in most emergency departments. Studies have shown its

IMAGING PROTOCOLS

Proper data acquisition and manipulation are crucial to helical CT evaluation of the aorta. A large volume of data must be acquired in a short time, with high resolution and at peak vascular enhancement. A number of factors, including patient preparation, contrast administration, and scanning parameters must be considered to gain fully the advantages offered by helical CT.

Etiology and Clinical Presentation

First reported in 1557 by Vesalius⁵⁶ and once a rare problem, traumatic rupture of the aorta has become a major cause of mortality from blunt chest trauma. In 1966, Greendyke²⁵ estimated 16% of all automobile accident–related deaths were due to aortic rupture. Recent statistics demonstrate that almost 3000 of the nearly 100,000 patients admitted to hospitals for blunt chest trauma have an aortic injury.³⁹ Since 1966, heightened awareness for the presence of aortic injuries, more rapid transport

SUMMARY

For the near future, CT will play the critical and dominant role in the evaluation of patients presenting with emergent aortic syndromes. Its convenience, accuracy, and utility in the rapid evaluation of not just the aorta, but the entire thorax, make it ideally suited for use in emergency settings. Further benefits are likely to be realized in speed and resolution with multislice CT, although it is as yet not widely available.

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Copyright © 1999 W. B. Saunders Company. Published by Elsevier Inc. All rights reserved.