The first clinical studies with our current prototype, 3D USCT II, enabled us to identify the necessary improvements for transition of our method to clinical practice. The main goals are to improve the contrast of reflection and transmission tomography, and to optimize the coverage of the imaged breast by a new geometry of the transducer distribution. Furthermore, for cost-effective industrial mass production, a self-calibration method allows us to relax the precision of the positioning of the transducers to 0.1 mm. The readout of the transducer arrays is now carried out by an ASIC, developed for a more cost-effective design. The coupling of the measuring device to the patient was optimized to cover the full size of the breast up to the pectoral muscles. Finally, the data acquisition and readout time were reduced to 1.5 minutes each by new micro-TCA electronics and larger FPGAs.