4D flow cardiac magnetic resonance postprocessing in congenital heart disease: SCMR FLIICR workgroup recommendations.

The large majority of patients with congenital heart disease (CHD) survive into adulthood in the modern era of surgical advancements. However, patients require life-long follow-up and non-invasive imaging is crucial for diagnostic and therapeutic purposes. Cardiovascular magnetic resonance (CMR) plays a major role in patients with CHD as it is a non-invasive and ionizing radiation free imaging tool which overcomes the technical limitations of echocardiography. 4D flow is an evolving technique for flow quantification allowing improved CMR exam quality and reduced scan time. However, comprehensive postprocessing of hemodynamics in CHD may be demanding. This document addresses the needs for an "ideal" post-processing software for 4D flow in patients with CHD. It provides information on general requirements, velocity encoding, offset and aliasing correction, visualization, segmentation and reconstruction as well as output data. This document aims to support stakeholders in the field to develop solutions for improved 4D flow post-processing and visualization in CHD patients and thus improve the accuracy and efficiency of patient care.