1. An analysis method for image data records of an examination object, comprising: providing image data records, wherein each image date record has a plurality of image data elements, wherein a position in a multidimensional space is assigned to each image data element, and wherein each image data element has an image data value, wherein the image data values of positionally corresponding image data elements of the image data records are specified by substantially positionally identical regions of the examination object; providing relevant image data records which include image data records of a region of the examination object in which a contrast agent has been introduced; dividing the relevant image data records into an empty region and a signal region by applying an overall assignment rule which is based upon the image data values of the image data elements of a plurality of image data records, such that each image data element of the relevant image data records is assigned to either the empty region or the signal region, wherein a size of the signal region changes over time as the contrast agent flows through the examination object; determining a closed outline fully containing the signal region of the relevant image data records wherein a size of the closed outline corresponds to the size of the signal region; and determining an analysis region based upon the closed outline of the relevant image data records to restrict a further analysis of the relevant image data record records to the analysis region wherein a size of the analysis region corresponds to the size of the closed outline thereby minimizing the size of the analysis region.