Table 1.
Definitions of statistics terms and imaging techniques
Terms | Definition |
Area under receiver operating characteristic curve (AUROC) | The AUROC is a measure of how well a parameter can distinguish between two diagnostic groups (diseased/normal) |
Accuracy | Consists of Trueness (proximity of measurement results to the true value) and Precision (repeatability or reproducibility of the measurement) |
Negative predictive value | Proportion of people with a negative test who are free of the target disorder |
Positive predictive value | Proportion of people with a positive test who have the target disorder |
Sensitivity | Proportion of people with the target disorder who have a positive test result |
Specificity | Proportion of people without the target disorder who have a negative test |
Imaging techniques | |
Ultrasonography-based transient elastography (FibroScan) | Technique whereby shear waves, at a low frequency of 50 Hz, are created by a vibrating probe and transducer applied to the skin overlying the liver |
Acoustic radiation force impulse | Use of shear acoustic waves remotely induced by the radiation force of a focused ultrasonic beam |
Magnetic resonance imaging-based Proton magnetic resonance spectroscopy | Quantifies hepatosteatosis by measuring proton signals from the acyl groups of hepatocyte triglyceride stores |
Magnetic resonance elastography | Obtained by depicting the propagated shear waves, and images of the shear waves are analyzed and used to generate the elastogram |