In the Concentration Curve Converter view, when selecting T1 weighted MRI, initially there are no options below the "3D Image" and "4D Image" selection. After selecting one of these, further options are shown. When the selected image type is deselected again, those additional options persist. This feels strange to me. I would suggest to either hide the further options again when deselecting 3D / 4D, or don't let the user completely deselect the option in the first place.