Update on 2-D array transducers for medical ultrasound

l½-D and 2-D arrays offer a myriad of new imaging modalities and benefits when compared to the linear array. However, with added benefits come many problems and challenges and l½-D and 2-D arrays are no exception. The authors give possible solutions to a number of these challenges. The increase in transducer channels needed in a 1½-D and 2-D array can be reduced using a sparse periodic or sparse random array. The complexity of the fabrication is overcome using a multilayer flexible connector designed and fabricated using microelectronic techniques. The low SNR of 1½-D and 2-D arrays can be circumvented with the application of multi-layer ceramic elements to optimize the SNR given a specific transmit and receive configuration. In addition, optoelectronic transmitters allow for the reduction in size and increase in flexibility of the transducer cable because of the use of fiber optics. With the reduction in the number of channels, improvement in transducer fabrication, and increase in transducer SNR, l½-D and 2-D arrays will be accepted as viable replacements for the linear arrays of today