Ultrasonic Imaging

Ever since the 1940's, ultrasonic imaging has been a key part of diagnostic medicine due to low cost, portability, and low health risks to the patient. One of its many uses is the detection of tumors and lesions in tissue, some of which may be cancerous. Ultrasonic imaging works by firing ultrasonic pulses at the tissue and measuring the resulting echoes to form an image.

Currently there are a wide variety of techniques available to improve the spatial resolution and signal to noise ratio. One such technique is resolution enhancement compression (REC). The REC technique is a type of coded excitation and pulse compression technique that utilizes the convolution equivalence principle to synthetically exchange the transducer impulse response with a desired impulse response by shaping the excitation signal appropriately. The resulting received pulse echo signals are the pulse compressed using a Wiener filter, resulting in an improvement in the axial resolution.

Another important technique is generic synthetic aperture ultrasound (GSAU). GSAU involves exciting the ultrasonic transducer elements to simulate an artificial focusing aperture. By creating this artificial aperture, the lateral resolution of the image is enhanced, improving the distinction of adjacent objects perpendicular to the beam axis.

The goal of this study is to combine these two techniques in an attempt to improve both components of resolution in a simulated ultrasound environment. These simulations will be formed using the MATLAB addon Field II, a standard tool in ultrasonic imaging simulation. To speed up the processing of these techniques, parallel processing will be utilized on a General Purpose Graphics Processing Unit (GPGPU).