A magnetic resonance imaging system for acquiring MRF magnetic resonance data from a subject within a region of interest, wherein the magnetic resonance imaging system comprises: - a processor for controlling the magnetic resonance imaging system; - a memory storing machine executable instructions and MRF pulse sequence commands, wherein the MRF pulse sequence commands are configured for controlling the magnetic resonance imaging system to acquire the MRF magnetic resonance data according to a magnetic resonance fingerprinting protocol, - wherein execution of the machine executable instructions causes the processor to: - acquire the MRF magnetic resonance data for the region of interest by controlling the magnetic resonance imaging system with the MRF pulse sequence commands and reconstruct MR fingerprints from the MRF magnetic resonance data; - receive magnetic resonance data descriptive of the region of interest; characterized in that execution of the the machine executable instructions further cause the processor to: - identify anatomical regions within the region of interest in the magnetic resonance data using an anatomical model; - select a local magnetic resonance fingerprinting dictionary from a set of magnetic resonance fingerprinting dictionaries for each of the anatomical regions, wherein the local magnetic resonance fingerprinting dictionary comprises a listing of calculated MRF signals for a set of predetermined substances specific to each of the anatomical regions; and - calculate a composition mapping of the predetermined substances for each of the anatomical regions using the MR fingerprints and the local magnetic resonance fingerprinting dictionary, wherein the composition mapping is a spatial average within each of the anatomical regions. - a processor for controlling the magnetic resonance imaging system; - a memory storing machine executable instructions and MRF pulse sequence commands, wherein the MRF pulse sequence commands are configured for controlling the magnetic resonance imaging system to acquire the MRF magnetic resonance data according to a magnetic resonance fingerprinting protocol, - wherein execution of the machine executable instructions causes the processor to: - acquire the MRF magnetic resonance data for the region of interest by controlling the magnetic resonance imaging system with the MRF pulse sequence commands and reconstruct MR fingerprints from the MRF magnetic resonance data; - receive magnetic resonance data descriptive of the region of interest; characterized in that execution of the the machine executable instructions further cause the processor to: - identify anatomical regions within the region of interest in the magnetic resonance data using an anatomical model; - select a local magnetic resonance fingerprinting dictionary from a set of magnetic resonance fingerprinting dictionaries for each of the anatomical regions, wherein the local magnetic resonance fingerprinting dictionary comprises a listing of calculated MRF signals for a set of predetermined substances specific to each of the anatomical regions; and - acquire the MRF magnetic resonance data for the region of interest by controlling the magnetic resonance imaging system with the MRF pulse sequence commands and reconstruct MR fingerprints from the MRF magnetic resonance data; - receive magnetic resonance data descriptive of the region of interest; - identify anatomical regions within the region of interest in the magnetic resonance data using an anatomical model; - select a local magnetic resonance fingerprinting dictionary from a set of magnetic resonance fingerprinting dictionaries for each of the anatomical regions, wherein the local magnetic resonance fingerprinting dictionary comprises a listing of calculated MRF signals for a set of predetermined substances specific to each of the anatomical regions; and - calculate a composition mapping of the predetermined substances for each of the anatomical regions using the MR fingerprints and the local magnetic resonance fingerprinting dictionary, wherein the composition mapping is a spatial average within each of the anatomical regions.