1. A system ( 100 ) for retrieving a volumetric image data subset comprised in a data storage ( 105 ) of volumetric image data sets, the system comprising: a first query unit ( 111 ; 113 ) for composing a first query for searching the data storage ( 105 ) for a volumetric image data set comprising the volumetric image data subset; a second query unit ( 112 ; 113 ) for composing a second query for searching the volumetric image data set for the volumetric image data subset, the second query comprising anatomical structure information for identifying an anatomical structure within the volumetric image data set; a first determination unit ( 121 ; 123 ) for determining the volumetric image data set, based on the first query; a second determination unit ( 122 ; 123 ) for determining the volumetric image data subset of the volumetric image data set, based on the anatomical structure identified within the volumetric image data set, using the anatomical structure information comprised in the second query; and a retrieval unit ( 125 ) for retrieving the determined volumetric image data subset.