A computer implemented method of generating quantitative data for biliary tree structures from volumetric medical imaging scan data; the method comprising: performing tubular enhancement on the volumetric medical imaging scan data to derive at least one tubeness measure for each voxel within the volumetric medical imaging scan data; wherein the tubular enhancement comprises, for each voxel within the volume of the medical imaging scan data, computing at least one metric distinguishing tubular structures from other structures and computing a tubeness measure for the respective voxel based at least partly on the at least one metric; performing segmentation of a volume of the medical imaging scan data to identify tubular biliary structures within the volume of the medical imaging scan data based at least partly on the at least one tubeness measure for each voxel; for at least one segmented tubular biliary structure within the volume of the medical imaging scan data, computing at least one set of quantitative structural parameters for at least one location along the length of the tubular biliary structure; determining centre-line positions at a plurality of locations along the length of the at least one segmented tubular biliary structure; for each of the plurality of locations along the length of the at least one segmented tubular biliary structure, determining a tube-width estimation for the at least one segmented tubular biliary structure; detecting at least one of strictures, dilatations and beading in the at least one segmented tubular structure based on the tube-width estimations along the length of the at least one segmented tubular structure by determining whether said tube-width estimations change along said length in accordance with pre-defined patterns of change, wherein each pattern allows for detection of a corresponding one of said at least one of strictures, dilatations and beading and outputting quantitative biliary tree data comprising the at least one set of quantitative structural parameters for the at least one segmented tubular biliary structure. performing tubular enhancement on the volumetric medical imaging scan data to derive at least one tubeness measure for each voxel within the volumetric medical imaging scan data; wherein the tubular enhancement comprises, for each voxel within the volume of the medical imaging scan data, computing at least one metric distinguishing tubular structures from other structures and computing a tubeness measure for the respective voxel based at least partly on the at least one metric; performing segmentation of a volume of the medical imaging scan data to identify tubular biliary structures within the volume of the medical imaging scan data based at least partly on the at least one tubeness measure for each voxel; for at least one segmented tubular biliary structure within the volume of the medical imaging scan data, computing at least one set of quantitative structural parameters for at least one location along the length of the tubular biliary structure; determining centre-line positions at a plurality of locations along the length of the at least one segmented tubular biliary structure; for each of the plurality of locations along the length of the at least one segmented tubular biliary structure, determining a tube-width estimation for the at least one segmented tubular biliary structure; detecting at least one of strictures, dilatations and beading in the at least one segmented tubular structure based on the tube-width estimations along the length of the at least one segmented tubular structure by determining whether said tube-width estimations change along said length in accordance with pre-defined patterns of change, wherein each pattern allows for detection of a corresponding one of said at least one of strictures, dilatations and beading and outputting quantitative biliary tree data comprising the at least one set of quantitative structural parameters for the at least one segmented tubular biliary structure.