MRI is often described as a marvel of modern medicine, but if you’ve ever wondered how it works at the level of physics, the answers are stranger and more beautiful than you might expect. Let’s start with a simple question: why do MRI machines listen to hydrogen and not something else, like carbon or oxygen? This article is a bit of a journey so buckle up and hold on — it is a twisty path.Why Hydrogen?The key lies in hydrogen’s simplicity. Each hydrogen atom has a single proton in its nucleus. T...