Motion-Artifact ‘Pseudo–Type A Dissection’ on Ungated CTA in a Morbidly Obese Patient with Resolution on ECG-Gated CTA: A Case Report

Abstract

We present a case of acute chest pain in a 48-year-old morbidly obese female with multiple comorbidities that raised suspicion for Acute Aortic Syndrome (AAS). The initial ungated PE-protocol CT angiogram (CTA) revealed a linear low-attenuation band in the ascending aorta consistent with a motion artifact-induced pseudo-flap. This finding led to two Transesophageal Echocardiograms (TEEs): the first, performed under conscious sedation, was positive; the second, performed under general anesthesia (GA) to minimize artifact, was negative. To definitively assess the findings, a confirmatory ECG-gated CTA was performed immediately after heart rate control, which was negative for both pulmonary embolism (PE) and aortic dissection. The final diagnosis was Acute Decompensated Heart Failure (ADHF), and the patient was discharged on Guideline-Directed Medical Therapy. This case illustrates that the ungated PE-protocol CTA is critically suboptimal for the ascending aorta and underscores the need to use a dedicated ECG-gated CTA when AAS is suspected, particularly in obese patients prone to motion artifacts, to prevent diagnostic error and unnecessary surgical intervention