Abstract 17893: Reducing Radiation Exposure and Contrast Use in Pre-TAVR Evaluation by Computed Tomography Angiography (CTA): A Quality Improvement Project

IntroductionAortic stenosis is the most common valvular heart disease with a prevalence of 13% in patients ≥75 years of age. Transcatheter aortic valve replacement (TAVR) has become a widely utilized alternative to surgical valve replacement. Our conventional CTA protocol for TAVR planning used 120mL of iodinated contrast with a tube voltage of 120kV. The risk of contrast-induced nephropathy (CIN) in this elderly population limited the use of CTA.PurposeWe sought to develop a CTA protocol using a high-pitch spiral acquisition mode to reduce radiation dose and contrast volume without compromising diagnostic image quality.Methods125 consecutive patients underwent CTA-TAVR evaluation using a dual-source scanner. Following an injection of 50 mL of contrast, retrospectively gated imaging of the heart followed by a rapid high pitched spiral was acquired from thoracic inlet through the ischial tuberosity using tube voltages of 80kV and 120kV, respectively. These studies were compared to a conventional protocol in 125 patients with retrospective gated acquisition of the chest and a non-gated technique of abdomen and pelvis, which utilized 120mL of contrast and tube voltage of 120kV. Two-tailed t-test was performed to evaluate differences between groups.ResultsTable 1 shows baseline patient and imaging characteristics. The low dose protocol significantly reduced radiation dose to 11.6±5.7mSv from 31.1±10.6mSv (p