BME PhD Thesis Defense Seminar: Etana C. Elegbe
Development of Single Tracking Location Acoustic Radiation Force Imaging for the Assessment of Liver Fibrosis Progression
Chronic liver disease is a global problem that affects millions of individuals. There is often a significant latent period between the onset of the disease and the clinical symptoms because of the liver's great ability to increase its level of operation in response to the demands of an injury. By the time the symptoms begin to manifest, the disease is usually at an advanced stage and the damage is substantial. Progressive liver fibrosis which is a non-specific wound healing response of hepatocytes to injury, is a common feature in the majority of chronic liver disease cases, and as such, liver fibrosis stage is considered to be of great prognostic value in the assessment of liver disease. The gold standard for staging fibrosis provides a wealth of information but is invasive and has several risks. Different elastographic techniques are thus currently being developed to non-invasively, and quantitatively stage liver fibrosis. One of the greatest challenges thus far in the use of elastography methods to stage fibrosis has been the ability to differentiate between mild to moderate stages of fibrosis. Single Tracking location Acoustic Radiation Force Impulse (STL ARFI) imaging is a novel ultrasound-elastographic technique that estimates the shear modulus of a material by tracking speckle motion in a single location. This reduces the variability in the shear modulus estimates by removing the speckle-induced bias in the estimates. The implication is that the ability to differentiate between mild to moderate stages of fibrosis is more feasible because of this improvement in precision. In addition, the implementation is done using a standard, ultrasound scanner that is readily available in a clinical setting. This work investigates the feasibility of STL ARFI as a tool to stage and monitor the progression of liver fibrosis.