Abstract: A method and apparatus are provided for performing photoacoustic tomography with respect to a sample that receives a pulse of excitation electromagnetic radiation and generates an acoustic field in response to said pulse. One embodiment provides an apparatus comprising an acoustically sensitive surface, wherein the acoustic field generated in response to said pulse is incident upon said acoustically sensitive surface to form a signal. The apparatus further comprises a source for directing an interrogation beam of electromagnetic radiation onto said acoustically sensitive surface so as to be modulated by the signal; means for applying a sensitivity pattern to the interrogation beam; and a read-out system for receiving the interrogation beam from the acoustically sensitive surface and for determining a value representing a spatial integral of the signal across the acoustically sensitive surface, wherein said spatial integral is weighted by the applied sensitivity pattern.