The present invention relates to a method, particularly for detecting inflamed tissue, like ulcerated, necrotic, granulation, fibrotic, fibrin rich-, neutrophil rich-, particularly collagen I, III, IV, V, VI rich-, or thrombin tissue in solid tissue in vivo using a pulsed laser with a wavelength in the range of e.g. 680 nm to 700nm and photon detectors which are detecting the re-emitted photons or acoustic sensors which detect the photoacoustic signal generated within the inflamed tissue. Using a pulsed laser with the wavelength 680 nm to 700nm leads to the excitation of endogenous occurring chromophores in inflamed tissue, like ulcerated, necrotic, granulation, fibrin rich-, neutrophil rich- and fibrotic tissue. A detected photoacoustic response can confirm the presence or absence of inflamed tissue. To better distinguish inflamed tissue from other naturally occurring chromophores like deoxygenated haemoglobin an additional wavelength in the range from e.g. 750nm to 770nm can be applied. Preferably, multiple photoacoustic signals are sensed from sensors that span a three dimensional space and the position of the inflamed tissue can be determined.
