Fig. 2.
(a) PA B-scan image of the 20 μm thick tungsten wire imaged at three locations. (b) Typical PA A-line signal (blue) and its Hilbert-transformed signal (i.e., radial LSF) for the tungsten wire target located at the focal point (Position 2). (c) Corresponding transverse LSF of the tungsten wire. (d) PA image of a black needle inserted into the inner leg of a rat.