A magnetic resonance imaging system for acquiring magnetic resonance data from a subject within a measurement zone, wherein the magnetic resonance imaging system comprises: - a processor for controlling the magnetic resonance imaging system; - a memory and/or a computer storage storing machine executable instructions (150, 152, 154), pulse sequence commands and a steady state magnetic resonance fingerprinting dictionary wherein the pulse sequence commands are configured for controlling the magnetic resonance imaging system to acquire the magnetic resonance data according to a magnetic resonance fingerprinting protocol, wherein the pulse sequence commands are configured for controlling the magnetic resonance imaging system to generate an RF pulse train, wherein the pulse sequence commands are configured for controlling the magnetic resonance imaging system to acquire the magnetic resonance data as multiple k-space traces, wherein the pulse sequence commands are configured for controlling the RF pulse train to be repeated for the acquisition of each of the multiple k-space traces, whereby a predetermined number of k-space traces are initially acquired until the magnetization has reached an equilibrium state, wherein the machine executable instructions causes the processor to: - sequentially acquire the multiple k-space traces of magnetic resonance data by controlling the magnetic resonance imaging system with pulse sequence commands; - calculate the abundance of each of a set of predetermined substances for k-space traces that are acquired after said initially acquired predetermined number of k-space traces of the multiple k-space traces, wherein the abundance of each of a set of predetermined substances is determined by comparing with the steady state magnetic resonance fingerprinting dictionary only the k-space traces that have been acquired after said initially acquired predetermined number of k-space traces of the multiple k-space traces, wherein the steady state magnetic resonance fingerprinting dictionary contains a listing of individual dictionary entries of calculated magnetic resonance signals in response to repetitions of the RF pulse train after magnetization has reached an equilibrium state for a set of predetermined substances and said magnetic resonance signals are calculated with a dynamic adaptation of the predetermined number of repetitions needed for the magnetization to reach an equilibrium state to use for the calculation to T 1 and T 2 values of the individual dictionary entries to be determined. - a processor for controlling the magnetic resonance imaging system; - a memory and/or a computer storage storing machine executable instructions (150, 152, 154), pulse sequence commands and a steady state magnetic resonance fingerprinting dictionary wherein the pulse sequence commands are configured for controlling the magnetic resonance imaging system to acquire the magnetic resonance data according to a magnetic resonance fingerprinting protocol, wherein the pulse sequence commands are configured for controlling the magnetic resonance imaging system to generate an RF pulse train, wherein the pulse sequence commands are configured for controlling the magnetic resonance imaging system to acquire the magnetic resonance data as multiple k-space traces, wherein the pulse sequence commands are configured for controlling the RF pulse train to be repeated for the acquisition of each of the multiple k-space traces, whereby a predetermined number of k-space traces are initially acquired until the magnetization has reached an equilibrium state, - sequentially acquire the multiple k-space traces of magnetic resonance data by controlling the magnetic resonance imaging system with pulse sequence commands; - calculate the abundance of each of a set of predetermined substances for k-space traces that are acquired after said initially acquired predetermined number of k-space traces of the multiple k-space traces, wherein the abundance of each of a set of predetermined substances is determined by comparing with the steady state magnetic resonance fingerprinting dictionary only the k-space traces that have been acquired after said initially acquired predetermined number of k-space traces of the multiple k-space traces, wherein the steady state magnetic resonance fingerprinting dictionary contains a listing of individual dictionary entries of calculated magnetic resonance signals in response to repetitions of the RF pulse train after magnetization has reached an equilibrium state for a set of predetermined substances and said magnetic resonance signals are calculated with a dynamic adaptation of the predetermined number of repetitions needed for the magnetization to reach an equilibrium state to use for the calculation to T 1 and T 2 values of the individual dictionary entries to be determined.