T2 Mapping: Exercises

Four interactive exercises on echoes, the CPMG echo train and myelin water. Exercise 2-1 is on RF phase and spin echoes: what the ±x and ±y RF phases do, spin echoes with perfect and imperfect pulses, and single-point measurements of T₂ and T₂^*. Exercise 2-2 is on stimulated echoes: three pulses, what an imperfect 180° does, and why every echo of a train mixes spin and stimulated echoes. Exercise 2-3 measures T₂ with an echo train: a timing game with perfect pulses, then with B₁ errors, the CPMG condition, and which echoes to fit. Exercise 2-4 is on myelin water: a two-component decay, the T₂ distribution of any pixel of a human brain slice at 3 T, and an MWF map built from it, compared with the published one (its data is CC BY 4.0: Dvorak et al., CALIPR Framework Myelin Water Imaging Supporting Data, Zenodo, Dvorak (2023)). Pick an exercise to open its slides. Use Open in new tab ↗ (top right of the slides) to present them in their own window. Click the slides first; the arrow keys play the games, so use the grey bars at the left and right edges (or Space and Page Down) to move between slides, F for full screen, S for speaker notes and Esc for the overview.