How many its resolution are needed for fluorescence lifetime imaging?
This is a deceptively simple question but the answer needs some careful thought. The first thing to remember is that the noise performance of the ‘weakest link’ in the imaging chain is the determining factor in the performance of a lifetime imaging system. If the ‘front-end’ of the imaging system is an image intensifier then this is almost certainly the noisiest component. Even if the camera viewing the image intensifier’s screen only worked to 5-bits resolution (i.e. 32 grey levels) this would usually be better than the performance of the intensifier. At first sight this seems to contradict the information in published accounts (including our own papers), where cameras capable of 12-16 bits are used to collect data. In fact, there is no contradiction. The process of measuring a fluorescence lifetime image involves image manipulations such as subtractions and ratiometric measurements. If the resulting image is to be of high quality then the signal-to-noise ratio of the precursor images
