Clinical Implementation of 4D Flow MRI in a Large Cardiovascular Imaging Practice: Motivation, Strategies, and Initial Experience

Like most sites during the initial onset of the COVID-19 pandemic, we sought to reduce exposure by dramatically reducing our dedicated clinical and research MRI scanning to a low quantity, resulting in both outpatient and research scanning being markedly reduced. During this period, our staff took this opportunity to set-up a working group in order to advise on scanner efficiency regarding our current cardiovascular MRI (CMR) scanning protocols. Given that our institution performs a high volume of CMR scans that utilize multiple 2-dimensional phase-contrast sequences to evaluate the flow across both the aortic and pulmonic valves and throughout the course of the aorta, our group decided that a concerted effort to fully implement fourdimensional phase-contrast imaging (hereafter referred to as 4D Flow) could improve scanner efficiency and perhaps provide more consistent flow quantification. This goal was implemented with the expectation that overall MR operations would be streamlined by both eliminating the numerous breath-hold 2D phase-contrast image acquisitions and decreasing technologist sequence planning time, while simultaneously improving patient comfort with the free-breathing 4D Flow sequence in cases requiring vascular flow evaluation.