Method of MR imaging of at least a portion of an object placed in the examination volume of an MR device , the method comprising the steps of: - subjecting the portion of the object to a first stimulated echo imaging sequence comprising at least two preparation RF pulses (α) radiated toward the portion of the object during a first preparation period and a sequence of reading RF pulses (β) radiated toward the portion of the object during a first acquisition period temporally subsequent to the first preparation period ; - acquiring a first set of FID signals (I FID ) and a first set of stimulated echo signals (I STE ) during the first acquisition period ; - subjecting the portion of the object to a second stimulated echo imaging sequence comprising at least two preparation RF pulses (α) radiated toward the portion of the object during a second preparation period and a sequence of reading RF pulses (β) radiated toward the portion of the object during a second acquisition period temporally subsequent to the second preparation period ; - acquiring a second set of FID signals (I FID ) and a second set of stimulated echo signals (I STE ) during the second acquisition period , wherein the first and second sets of FID signals (I FID ) have different T 1 -weightings and/or the first and second sets of stimulated echo signals (I STE ) have different T 1 -weightings; - deriving a B 1 map indicating the spatial distribution of the RF field of the RF pulses within the portion of the object from the acquired first and second sets of FID (I FID ) and stimulated echo (I STE ) signals, wherein the different T 1 -weightings are made use of to compensate for influences on the B 1 map caused by T 1 relaxation. - subjecting the portion of the object to a first stimulated echo imaging sequence comprising at least two preparation RF pulses (α) radiated toward the portion of the object during a first preparation period and a sequence of reading RF pulses (β) radiated toward the portion of the object during a first acquisition period temporally subsequent to the first preparation period ; - acquiring a first set of FID signals (I FID ) and a first set of stimulated echo signals (I STE ) during the first acquisition period ; - subjecting the portion of the object to a second stimulated echo imaging sequence comprising at least two preparation RF pulses (α) radiated toward the portion of the object during a second preparation period and a sequence of reading RF pulses (β) radiated toward the portion of the object during a second acquisition period temporally subsequent to the second preparation period ; - acquiring a second set of FID signals (I FID ) and a second set of stimulated echo signals (I STE ) during the second acquisition period , wherein the first and second sets of FID signals (I FID ) have different T 1 -weightings and/or the first and second sets of stimulated echo signals (I STE ) have different T 1 -weightings; - deriving a B 1 map indicating the spatial distribution of the RF field of the RF pulses within the portion of the object from the acquired first and second sets of FID (I FID ) and stimulated echo (I STE ) signals, wherein the different T 1 -weightings are made use of to compensate for influences on the B 1 map caused by T 1 relaxation. <EOS>