Real time rectilinear volumetric imaging
The current Duke real time volumetric scanner uses 40×40 arrays to scan a pyramidal volume comprised of 64 sector scans in the elevation direction. This scan format is primarily useful for cardiac imaging to avoid interference from the ribs. However, a real time rectilinear volumetric scan with a wider field of view close to the transducer could prove more useful for abdominal, breast, or vascular imaging. Therefore, several different sparse array patterns have been investigated for 5 MHz transducers through computer simulation using the Field II software of Jensen. The sparse arrays including a periodic array, a random array and a Mills cross array were compared to a fully sampled array which served as the "gold standard." The Mills cross design showed the best overall performance under the current system constraints. 94×94 Mills cross arrays including 372 elements have been fabricated. Preliminary real time rectilinear volumetric images of a wire phantom using the Mills Cross were obtained.