Non-contrast microvascular flow imaging in abdominal ultrasound: a pictorial essay

Abstract The evaluation of low-velocity blood flow and complex vascular patterns remains a recognized limitation of conventional color Doppler ultrasound in abdominal imaging. Microvascular flow imaging (MV-Flow) is an advanced Doppler technique designed to enhance sensitivity to slow and heterogeneous blood flow while effectively suppressing tissue motion artifacts. This pictorial essay illustrates the main sonographic applications of MV-Flow across a wide spectrum of abdominal clinical scenarios, including arterial flow alterations, venous and portal vascular disorders, post-transplantation hemodynamic changes, inflammatory parenchymal conditions, and selected focal liver lesions. Representative imaging examples are provided to highlight characteristic flow patterns and vascular architectures that are not readily appreciable with conventional Doppler techniques. In this context, MV-Flow represents a valuable complementary tool in abdominal ultrasound, improving pattern recognition and diagnostic confidence during non-invasive clinical assessment. In addition, by improving the non-invasive characterization of vascular and perfusion patterns, MV-Flow may reduce the need for further cross-sectional imaging, potentially lowering healthcare costs and minimizing patient exposure to ionizing radiation.