FIG. 2.
Reconstructed TAT images, using the flat ultrasonic detector, of a needle (18 gauge, 1 mm in diameter) inserted inside a pork fat base placed at a distance of (a) ~4 mm, (b) ~14 mm, (c) ~32 mm, (d) ~50 mm, and (e) ~64 mm from the scanning center. Corresponding TAT images obtained with the negative lens detector are shown in (f), (g), (h), (i), and (j), respectively. (k) Location of the needle inside the scanner is shown.