Exact solution of the CPMG pulse sequence with phase variation down the echo train: Application to R2 measurements

► Exact CPMG simulation eliminates frequency offset effects in measured R2s. ► Grouped phase variation in CPMG removes oscillation and field-inhomogeneity effects. ► Second-order approximation provides reliable R2s to ±12γB1 offset. ► Exact CPMG simulation provides reliable R2s to ±γB1 offset.