Increasing field of view of high frame rate ultrasonic imaging

A high frame rate imaging method has been developed recently based on the theory of limited diffraction beams for medical diagnosis. This method constructs images in a direction normal to the transducer surface. In this report, the high frame rate method is extended so that it will not only construct images in the normal direction, but also in any oblique directions. This increases the image construction area because images from several oblique angles can be combined. A new equation has been derived for this extension. A computer simulation was performed. Results show that the field of view of images constructed with the extended method is increased from about 15.74 deg to about 96.57 deg with a linear array of a width (foot print) of about 18.288 mm after combining images from only seven angles (the depth of the images is assumed to be 66.12 mm). This work is significant because a large field of view with a small transducer footprint is desirable for high frame rate heart imaging. [Work supported in part by Grant No. HL60301 from NIH.]