Bloch-Siegert (BS) based B mapping methods use off-resonant pulses to encode quantitative B information into the signal phase. It was recently shown that the principle behind BS-based B mapping can be expanded from spin echo (BS-SE) and gradient-echo (BS-FLASH) based BS B mapping to methods such as Carr, Purcell, Meiboom, Gill (CPMG)-based turbo-spin echo (BS-CPMG-TSE) and multi-spin echo (BS-CPMG-MSE) imaging. If CPMG conditions are preserved, BS-CPMG-TSE allows fast acquisition of the B information and BS-CPMG-MSE enables simultaneous mapping of B, M0, and T2. To date, however, two separate MRI experiments must be performed to enable the calculation of B maps. This study investigated a modified encoding strategy for CPMG BS-based methods to overcome this limitation. By applying a “bipolar” off-resonant BS pulse before the refocusing pulse train, the needed phase information was able to be encoded into different echo images of one echo train. Thus, this technique allowed simultaneous B and T2 mapping in a single BS-CPMG-MSE experiment. To allow single-shot B mapping, this method was also applied to turbo-spin echo imaging. Furthermore, the presented modification intrinsically minimizes phase-based image artifacts in BS-CPMG-TSE experiments. Magn Reson Med, 2012. © 2011 Wiley Periodicals, Inc.