Perfusion MRI Techniques: Beyond DSC

Abstract

The use of brain hemodynamics is important in the assessment of numerous pathophysiologic conditions. The measurement of perfusion or delivery of blood to tissues by MR imaging is essential for neuroradiologists to understand and appropriately apply to clinical practice. Several different approaches are used. DSC and dynamic contrast-enhanced MR imaging study the signal change (according to T2* and T1, respectively) induced by an exogenous contrast agent, allowing the measurement of CBF, CBV, and time-related parameters. Blood oxygen level‐dependent (BOLD) MR imaging measures the T2* signal changes induced by the paramagnetic molecule deoxyhemoglobin. BOLD MR imaging provides complex measurements because the signal varies not only with changes in CBF but also with several other parameters such as tissular oxygen uptake and brain activation. Arterial spin-labeling MR imaging is a technique relying on labeled endogenous water as a tracer. By measuring the signal difference between 2 sets of acquisitions (labeling and control), arterial spin-labeling MR imaging calculates cerebral perfusion in a quantitative manner. This article aims to review the fundamentals of perfusion MR imaging techniques essential to any neuroradiology practice along with their advantages, disadvantages, and applications to research and clinical care.Learning Objective: To review DSC MR imaging and alternative MR imaging perfusion techniques, focusing on methodology, advancements, and applications essential for the neuroradiologist to understand and clinically use these techniques