1. A scan region determining apparatus for determining a scan region of a subject to be scanned by a scanning system, the scan region determining apparatus comprising: an overview image providing unit configured to provide an overview image of a subject, an element position indicator determination unit configured to determine an intermediate scan region being indicative of a position of an element of the subject to be scanned, wherein the element position indicator determination unit is adapted to determine the intermediate scan region with respect to and based on the overview image, wherein the intermediate scan region is an intermediate scan region plan box, a template image providing unit configured to provide a template image of a template subject, which corresponds to the subject to be scanned, and for providing a template scan region including a template element, which corresponds to the element of the subject to be scanned, wherein the template image providing unit is adapted to provide a template scan region, which is defined with respect to the template image, wherein the template scan is a template scan region plan box, spatial transformation determination unit configured to determine a spatial transformation defining a registration of the overview image and the template image with respect to each other, wherein initially the overview image and the template image are registered by using the determined intermediate scan region being indicative of the position of the element of the subject to be scanned with respect to the overview image, a scan region determination unit configured to determine a final scan region by projecting the template scan region onto the overview image by using the determined spatial transformation, wherein the final scan region is a final scan region plan box.