Evaluating Multi-Institution Variability in 4D flow MRI Hemodynamic Characterization of Type B Aortic Dissection with 3D Printed Models

Acute type B aortic dissection (TBAD) is associated with an in-hospital mortality of 10% and 3-year mortality approaching 25%. Increased pressure in the false lumen (FL) drives aortic remodeling and increases the risk of adverse outcomes and treatments for uncomplicated TBAD are aimed at decreasing pressure in the FL. However, prospectively identifying patients most likely to benefit from anti-hypertensive medical therapy versus those requiring thoracic endovascular aortic repair (TEVAR) remains challenging. Thus, non-invasive evaluation of FL hemodynamics has the potential to be important in TBAD risk-stratification and treatment follow-up. 4D flow MRI is a well-validated, non-invasive imaging technique for evaluation of aorta hemodynamics. Multiple studies, including several from our group and our close collaborators, have now shown that 4D flow can qualitatively and quantitatively evaluate hemodynamics in the false lumen of TBAD patients, and we have also shown that 3D printed models of TBAD patients can are effective tools for studying true lumen (TL) and FL hemodynamics. Given these findings, we believe 4D flow MRI has outstanding potential to provide personalized assessment of TBAD hemodynamics and significantly improve risk-stratification. However, because of the relatively low incidence of this disease at any given institution, multi-center studies are required to appropriately power a prospective study evaluating the role of 4D flow in TBAD assessment. To adequately perform this larger study and ultimately provide optimized patient care, the site-specific variability of 4D flow hemodynamic assessment must be understood.