The lack of open access to the pre-beamformed data of an ultrasound scanner has limited the research of novel imaging methods to a few privileged laboratories. To address this need, we have developed a pre-beamformed data acquisition (DAQ) system that can collect data over 128 array elements in parallel from the Ultrasonix series of research-purpose ultrasound scanners. Our DAQ system comprises three system-level blocks: 1) a connector board that interfaces with the array probe and the scanner through a probe connector port; 2) a main board that triggers DAQ and controls data transfer to a computer; and 3) four receiver boards that are each responsible for acquiring 32 channels of digitized raw data and storing them to the on-board memory. This system can acquire pre-beamformed data with 12-bit resolution when using a 40-MHz sampling rate. It houses a 16 GB RAM buffer that is sufficient to store 128 channels of pre-beamformed data for 8000 to 25 000 transmit firings, depending on imaging depth; corresponding to nearly a 2-s period in typical imaging setups. Following the acquisition, the data can be transferred through a USB 2.0 link to a computer for offline processing and analysis. To evaluate the feasibility of using the DAQ system for advanced imaging research, two proof-of-concept investigations have been conducted on beamforming and plane-wave B-flow imaging. Results show that adaptive beamforming algorithms such as the minimum variance approach can generate sharper images of a wire cross-section whose diameter is equal to the imaging wavelength (150 μm in our example). Also, planewave B-flow imaging can provide more consistent visualization of blood speckle movement given the higher temporal resolution of this imaging approach (2500 fps in our example).

An ultrasound-based system is created to label the lumbar vertebrae for the purpose of percutaneous needle insertion. Many lumbar punctures have a preferable vertebral level for needle insertion, but the traditional method of manual palpation is known to be inaccurate for determining the level. Needle insertion for epidural anesthesia in obstetrics is preferably performed at the L3-L4 interspace and miscalculation can lead to complications such as nerve damage and paralysis. Similar risks occur for other spinal needle insertions. In this paper, an ultrasound-based system is devised that creates panorama images of lumbar vertebrae with an extended field of view starting from the coccyx. The vertebrae are labeled with a novel image processing algorithm. Since the coccyx is relatively easy to locate by palpation, the labels of the vertebrae from the panorama can be converted to skin location on the subject. The method is validated against independent measurements by a sonographer.

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