Apparatus and method for fluorescence imaging and tomography using spatially structured illumination

A method for performing depth sectioned fluorescence imaging of a turbid sample including a fluorescent turbid medium, using an apparatus for quantitative modulated fluorescence imaging, the apparatus including projection optics with a first optical axis, to expose the turbid sample to a periodic pattern of excitation radiation to provide depth-resolved discrimination of fluorescent structures within the turbid medium;

• an image capture module, including a second optical axis and a detection beam path, to receive a data image from the sample;
• and a signal processor to transform the data image from the sample, spatially filter the transformed data image from the sample, and reconstruct the filtered, transformed data image from the sample, the method comprising:
• providing the sample on a subject stage of the apparatus for quantitative modulated fluorescent imaging;
• inclining the first optical axis relative to the second optical axis;
• providing in the projection optics an object plane and an image plane;
• inclining the projection optics at an angle of inclination relative to an image plane of the apparatus, the angle of inclination being selected such that the component of excitation radiation incident upon the sample that is not absorbed by the sample is scattered in such a way that substantially reduces excitation radiation from reaching the detection beam path;
• and
• providing the periodic pattern of excitation radiation with a periodicity in a direction perpendicular to a direction of the projection of the first optical axis onto the image plane, so that the phase of the periodic pattern of excitation radiation does not change with increasing depth into an image space.