The noninvasive quantification of fat content in the liver is a longstanding goal with major clinical significance. Non-alcoholic fatty liver disease (steatosis) is the most prevalent chronic liver disease, affecting approximately 25% of the global population, yet options for measuring and monitoring the progression of steatosis have been limited. To address this need, a number of efforts have been pursued to quantify steatosis using different imaging modalities. Ultrasound has potential for the study of steatosis in livers, and ultrasound assessments have utilized a number of approaches. However, none of these approaches are currently in widespread clinical use, and many studies still rely on biopsy or MRI techniques for a reference standard measurement. Furthermore, the presence of simultaneous medical conditions that also influence these parameters as co-factors complicates their interpretation. For these reasons, the goal of obtaining accurate measures of liver steatosis from ultrasound imaging systems remains a compelling objective.
The University of Rochester has developed a method for absolute quantitative estimates of the volume fraction V of liver fat. This method requires a pair of measurements to be input that are now becoming more available: the attenuation and speed of sound/shear wave speed in a patient's liver. Using either of these pairs, researchers calculate the volume fraction of liver fat producing an absolute quantification of steatosis.
This approach could be an alternative method to noninvasively assess the in vivo hepatic fat content using ultrasound systems that are less expensive, more portable, and more widely globally available than MRI systems.
Non-alcoholic fatty liver disease.