E5471. What’s in a Name? Evaluating the Frequency With Which Radiologists Appropriately Diagnose the Ascending Aorta as Aneurysmal
  1. Michael Corbin; University of Pennsylvania
  2. Tessa Cook; University of Pennsylvania
  3. William Boonn; University of Pennsylvania
Patients whose imaging reveals an aneurysmal thoracic aorta often get repeat imaging, but how often is it truly indicated? Yousef et al. observed that there was a range of descriptors (aneurysm, ectasia, etc.) used when describing thoracic aortic aneurysms (TAAs) and presented a calculator for assigning aortic diagnosis based on age, sex, height, weight, and aortic dimension. Zafar et al. used a nomogram with aortic height index (AHI) to determine risk categorization for TAA rupture and demonstrated that AHI is a viable tool for predicting adverse outcomes for TAA. The aim of our study is to evaluate the difference between our radiologists’ diagnosis of TAA, the quantitative calculator-based assessment of TAA diagnosis, and AHI-based adverse event risk.

Materials and Methods:
Initially, 464 patients with thoracic ascending aortic aneurysms were reviewed. Radiologic, anthropometric, and clinical data were manually obtained retrospectively from the EMR. Patients with congenital aortic malformations, bicuspid aortic valves, ascending aortic graft repairs, traumatic aortic injury, or Stanford type A and type B dissections, were excluded. CTA report data was reviewed to determine TAA sizes. The aortic dimension analyzed was the documented “ascending aorta” size in the CTA reports. Body surface area was computed using patients’ height and weight. Aortic size index was defined as aortic diameter (cm) divided by body surface area (m2). AHI was calculated as aortic diameter (cm) divided by patient height (m). Aortic diagnosis was assigned using the aforementioned calculator formula. Statistical analysis was performed.

After exclusions, 363 patients were included in the analysis (75% male; average age 67 years). Across 324 patients, our radiologists used six different terms to describe the ascending aorta, which mapped to “normal” (16), “dilated” (38), and “aneurysmal” (270). The average ascending aorta size across all 363 patients was 4.64 cm. A total of 270 (74%) patients were diagnosed as having ascending aortic aneurysms by our radiologists, while only 54 (15%) patients were found to be aneurysmal by the calculator (p < 0.001). Most (72%) of our patients were characterized as having moderate, high, or severe risk of adverse event by AHI. Patients with a dilated aorta (27/38) and patients with an aneurysmal aorta (172/270) were found to be at moderate risk of adverse event by AHI. Only 33 patients with an aneurysmal aorta were found to be at high or severe risk of adverse event by AHI.

We currently use a variety of descriptors when characterizing TAA on CTA, and we qualitatively label more aortas as aneurysmal compared to a quantitative assessment that accounts for patient size. Incorporating these additional biometric data may increase specificity of the TAA characterization and risk stratification to decrease inappropriate imaging utilization.