The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through representation of such organizations on expert panels. Participation on the expert panel does not necessarily imply endorsement of the final document by individual contributors or their respective organization. Reprint requests to: publications@acr.org Suspected Acute Aortic Syndrome of the left subclavian artery, and propagates antegrade along the descending aorta. Rarely, the proximal intimal tear occurs in an unusual location, such as the abdominal aorta [6]. Stanford type A dissection refers to any dissection involving the ascending aorta and therefore is equivalent to DeBakey type I and type II. Stanford type B dissection is any AD that does not involve the ascending aorta, including dissections that originate in the aortic arch. Stanford type B dissection is therefore equivalent to DeBakey type III [10]. Both the DeBakey and Stanford classifications are ambiguous in regard to AD starting on the aortic arch. Such lesions may be best described as Stanford type B with arch involvement [6,11]. All elements are essential: 1) timing, 2) reconstructions/reformats, and 3) 3-D renderings. Standard CTs with contrast also include timing issues and reconstructions/reformats. Only in CTA, however, is 3-D rendering a required element. This corresponds to the definitions that the CMS has applied to the Current Procedural Terminology codes. Discussion of Procedures by Variant Variant 1: Acute chest pain; suspected acute aortic syndrome Aortography Chest Historically, conventional angiography was considered the reference standard for diagnosing AAS with sensitivity, specificity, positive predictive value, and negative predictive value of 88%, 94%, 96%, and 84%, respectively, reported for identification of an intimal flap [13].
Suspected Acute Aortic Syndrome. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through representation of such organizations on expert panels. Participation on the expert panel does not necessarily imply endorsement of the final document by individual contributors or their respective organization. Reprint requests to: publications@acr.org Suspected Acute Aortic Syndrome of the left subclavian artery, and propagates antegrade along the descending aorta. Rarely, the proximal intimal tear occurs in an unusual location, such as the abdominal aorta [6]. Stanford type A dissection refers to any dissection involving the ascending aorta and therefore is equivalent to DeBakey type I and type II. Stanford type B dissection is any AD that does not involve the ascending aorta, including dissections that originate in the aortic arch. Stanford type B dissection is therefore equivalent to DeBakey type III [10]. Both the DeBakey and Stanford classifications are ambiguous in regard to AD starting on the aortic arch. Such lesions may be best described as Stanford type B with arch involvement [6,11]. All elements are essential: 1) timing, 2) reconstructions/reformats, and 3) 3-D renderings. Standard CTs with contrast also include timing issues and reconstructions/reformats. Only in CTA, however, is 3-D rendering a required element. This corresponds to the definitions that the CMS has applied to the Current Procedural Terminology codes. Discussion of Procedures by Variant Variant 1: Acute chest pain; suspected acute aortic syndrome Aortography Chest Historically, conventional angiography was considered the reference standard for diagnosing AAS with sensitivity, specificity, positive predictive value, and negative predictive value of 88%, 94%, 96%, and 84%, respectively, reported for identification of an intimal flap [13].