3D Harmonic Echocardiography:

Three dimensional (3D) echocardiography has recently developed from an experimental technique in the ’90 towards an imaging modality for the daily clinical practice. This dissertation describes the considerations, implementation, validation and clinical application of a unique concept for harmonic 3D echocardiography. Part I firstly illustrates the advantages of harmonic imaging with a new transducer design tool, allowing the simulation of steered nonlinear acoustic beams. Then this dissertation introduces the fast rotating ultrasound (FRU-) transducer, which serves as a cost effective alternative for full- volume echocardiography with optimal harmonic capabilities. Measurement of the left ventricular (LV) volume has major diagnostic and prognostic importance. In the part II this basic application of the FRU-transducer is explored. Both a commercially available and self-developed quantification application are evaluated for LV volume measurement. Both quant! ification applications use advanced semi-automatic detection algorithms for endocardial border delineation. In addition, the efficiency of LV volume quantification is optimized by determining the minimal number of long-axis images required for accurate LV volume measurement. More advanced applications are investigated in part III. First, 3D echocardiography during hemodialysis is compared with two dimensional echocardiography. The study gives a good example of the flexible application of 3D echocardiography. Subsequently, the advantages of 3D contrast harmonic imaging are explored. Whether 3D echocardiography can assist in the implantation of resynchronization devices is investigated next. The feasibility of regional wall motion analysis for this purpose concludes part III.