3D Shear-wave Imaging Transducer for Liver Cancer Screening

Abstract Liver cancer is one of the leading causes of cancer death worldwide and is expected to account for an increasing percentage of cancer deaths in the United States, with hepatocellular carcinoma (HCC) accounting for approxi- mately 80% of liver cancer cases. Treatment options for HCC vary with the stage of detection, with early detec- tion leading to substantial improvement in survival rates. Unfortunately, current surveillance techniques for HCC have low sensitivity. Standard B-mode ultrasound is the recommended surveillance method, however, the sen- sitivity of ultrasound for detection of HCC depends upon the size of the nodule, the background coarseness in cirrhotic livers, and patient body habitus. Reported HCC lesion detection rates during 2D B-mode ultrasonic imaging range from 58-89%, with much lower detection rates found for small focal liver lesions in cirrhotic livers. CT and MRI are used for confirmation after a suspicious region has been identified with ultrasound, but these modalities are not cost-effective for surveillance, and in the case of CT, pose additional radiation risk. Commercial 2D ultrasonic shear wave elasticity imaging (SWEI) measurements have been shown by numerous groups to have significantly higher contrast for HCC than B-mode imaging and have demonstrated success in hepatic lesion visualization. However, these systems have challenges arising from limited acoustic output, with respect to frame rate, penetration depth, measurement heterogeneity in stiffer livers. Complete volume assess- ment of the liver with 2D imaging also extends exam time. These limitations preclude its use for widespread HCC screening. This work will address these limitations by developing a high-power matrix array capable of wide field-of-view 3D SWEI imaging, with additional 'push' capability that will enable rapid SWEI assessment of the full liver volume. To achieve the clinical objective, this project will initially develop 3D SWEI research prototype transducers, a prerequisite for the full development of 3D SWEI methods and applications. The prototypes developed in this project will enable development of 3D SWEI imaging methods, development and validation of the HCC screening application. This will provide a powerful tool for high contrast HCC screening and treatment monitoring leading to an effective method for liver cancer screening, allowing early diagnosis and intervention, yielding substantial improvements in survival rate.