The purpose of this prospective study is to compare point-of-care focused cardiac ultrasound (FOCUS) to thoracic computed tomographic angiography (CTA) in the measurement of ascending aortic dimensions. We hypothesize that FOCUS will demonstrate good agreement with CTA in the measurement of ascending aortic dimensions and accurately detect dilation and aneurysmal disease.

Nonspecific chest pain is frequently encountered in the emergency department. Accounting for over 13,000 deaths annually, aortic aneurysmal disease is a potential cause of chest pain.There are multiple diagnostic imaging modalities in practice to interrogate the thoracic aorta, with the most common being computed tomographic angiography (CTA), trans-thoracic echocardiography (TTE) and trans-esophageal echocardiography (TEE), each with its own advantages and limitations. In the ED setting, point-of-care (POC) focused cardiac ultrasound (FOCUS) is increasingly being used as an adjunct to the emergency physician's (EP) workup of undifferentiated chest pain. Based on prior retrospective data FOCUS and CTA appear to have good agreement. This studies aims to confirm these findings through prospective evaluation

Specific Aims

Aim 1: To prospectively compare Point of Care (POC) Focused Cardiac Ultrasound (FOCUS) to thoracic computed tomographic angiography (CTA) in the measurement of ascending aortic dimensions.

Maximal diameter measurements of the ascending thoracic aorta by FOCUS will be compared to CTA. Bland Altman plots with 95% limits of agreement will be used to determine clinical and statistical significance.

Hypothesis: 95% limits of agreement between FOCUS and CTA will be within +/- 5 mm.

Aim 2: To determine the diagnostic accuracy of Point-of-Care Focused Cardiac Ultrasound for the detection of thoracic aortic dilation and aneurysm with computed tomographic angiography as the reference standard

Sensitivity, Specificity and Accuracy of FOCUS will be computed with CTA as the reference standard.

Inclusion Criteria:

• All patients aged 18 years and older presenting to the ED for whom a thoracic CTA has been ordered.

Exclusion Criteria:

• Refusal of verbal consent for ultrasound.
• Inability to obtain informed written consent for data collection from either the patient or the patients decision-making surrogate

Patients 18 years of age or older presenting to an urban, academic, and level I emergency department with estimated volume of approximately 90,000 patients per year.