NOVELTY - The method involves illuminating an object i.e. aneurysm, with measuring light with wavelengths ranging from 790 nanometer to 820 nanometer, and recording a sequence of images (21, 22) i.e. white light image, of the illuminated object. The sequence of images is evaluated by associating pixels in the sequence of images to which locations of the object are imaged with an analysis image value. The analysis image value depends on temporal changes of image values of the pixels in the sequence of images in a frequency range of below 100 Hertz.