In vivo measurement of T₂ distributions and water contents in normal human brain

Using a 32‐echo imaging pulse sequence, T 2 relaxation decay curves were acquired from five white‐ and six gray‐matter brain structures outlined in 12 normal volunteers. The water contents of white and gray matter were 0.71 (0.01) and 0.83 (0.03) g/ml, respectively. All white‐matter structures had significantly higher myelin water percentages (signal percentage with T 2 between 10 and 50 ms) than all gray‐matter structures. The range in...