A method for creating an age-specific quantitative atlas for a biological object, the method comprising the following successive steps: a)obtaining a quantitative map of the biological object for each subject of a healthy subject population; b)generating an age-specific initial map for said biological object using a weighted mean of the intensities of the quantitative maps obtained at the previous step, wherein said age-specific initial map is generated for a specific age, wherein for each of said quantitative maps obtained at the previous step, a contribution to the average depends on a difference between the specific age and the age of the biological object from which said quantitative maps obtained at the previous step has been obtained, wherein if said difference is greater than a predefined age limit value, then the contribution is zero, otherwise said contribution depends on said difference in that the smaller said difference, the higher said contribution; c)spatially registering each of the quantitative maps obtained at the previous step on the age-specific initial map; d)repeating the generating and registering steps iteratively so that at each iteration a new age-specific initial map is created from the quantitative maps obtained at the end of the previous spatial registration step, and the quantitative maps obtained at the end of the previous spatial registration step are then further registered on the new age-specific initial map until reaching a first predefined alignment threshold between all spatially registered quantitative maps; e)storing the new age-specific initial map obtained at the end of the iterative process of the repeating step as the age-specific quantitative atlas for a biological object characterized by said specific age. a)obtaining a quantitative map of the biological object for each subject of a healthy subject population; b)generating an age-specific initial map for said biological object using a weighted mean of the intensities of the quantitative maps obtained at the previous step, wherein said age-specific initial map is generated for a specific age, wherein for each of said quantitative maps obtained at the previous step, a contribution to the average depends on a difference between the specific age and the age of the biological object from which said quantitative maps obtained at the previous step has been obtained, wherein if said difference is greater than a predefined age limit value, then the contribution is zero, otherwise said contribution depends on said difference in that the smaller said difference, the higher said contribution; c)spatially registering each of the quantitative maps obtained at the previous step on the age-specific initial map; d)repeating the generating and registering steps iteratively so that at each iteration a new age-specific initial map is created from the quantitative maps obtained at the end of the previous spatial registration step, and the quantitative maps obtained at the end of the previous spatial registration step are then further registered on the new age-specific initial map until reaching a first predefined alignment threshold between all spatially registered quantitative maps; a new age-specific initial map is created from the quantitative maps obtained at the end of the previous spatial registration step, and the quantitative maps obtained at the end of the previous spatial registration step are then further registered on the new age-specific initial map until reaching a first predefined alignment threshold between all spatially registered quantitative maps; e)storing the new age-specific initial map obtained at the end of the iterative process of the repeating step as the age-specific quantitative atlas for a biological object characterized by said specific age.