A control method is disclosed for determining a quality indicator of medical technology recording results data from a tomography scan of an examination structure, which scan is supported by a contrast agent, by way of a tomography system. According to an embodiment of the invention, at least one control parameter value is automatically derived from the recording results data in respect of a contrast agent image region during and/or directly after the tomography scan, which value represents a quality of the recording results data in the contrast agent image region. A control system for such a determination is also disclosed.