An openable motor vehicle roof is provided which includes a cover which in the closed position closes at least part of the roof opening, a cover-mounted cover carrier which is provided with a first crank path, and a slide which can be moved in the lengthwise direction of the roof by means of a drive in a first roof-mounted guide channel. Structures within the tissue where measured-analyte-induced changes to the OCT data dominate over changes induced by other analytes are identified by focusing on highly localized regions of the data curve produced from the OCT scan which correspond to discontinuities in the OCT data curve. Energy waste to hydraulic oil heat and fuel consumption is significantly reduced.