1. A computer-implemented method for detecting an undesirable medical condition of a liver in a subject, comprising: capturing scan data of the subject using computed tomography, where the scan data includes the liver of the subject; constructing a three-dimensional surface model of a liver from the scan data; extracting image data representing the liver from the scan data using the three-dimensional surface model, where the image data is comprised of a stack of two-dimensional data slices; determining a measure of the liver from the image data; determining a random variable from the measure of the liver, where the random variable is indicative of at least one of a shape or texture of the liver; and detecting an undesirable condition of the liver using a statistical model comprised of the random variable.