 In 1995 other researchers formulated a general reconstruction algorithm by which 2D thermoacoustic images could be "computed" from their "projections," i.e.thermoacoustic computed tomography (TCT).By 1998 researchers at Indiana University Medical Center extended TCT to 3D and employed pulsed microwaves to produce the first fully three-dimensional (3D) thermoacoustic images of biologic tissue [an excised lamb kidney (Fig.