at lower left). the finding is confirmed by histology. elastography is used for the investigation of many disease conditions in many organs. it can be used for additional diagnostic information compared to a mere anatomical image, and it can be used to guide biopsies or, increasingly, replace them entirely. biopsies are invasive and painful, presenting a risk of hemorrhage or infection, whereas elastography is completely noninvasive. elastography is used to investigate disease in the liver. liver stiffness is usually indicative of fibrosis or steatosis (fatty liver disease), which are in turn indicative of numerous disease conditions, including cirrhosis and hepatitis. elastography is particularly advantageous in this case because when fibrosis is diffuse (spread around in clumps rather than continuous scarring), a biopsy can easily miss sampling the diseased tissue, which results in a false negative misdiagnosis. naturally, elastography sees use for organs and diseases where manual palpation was already widespread. elastography is used for detection and diagnosis of breast, thyroid, and prostate cancers. certain types of elastography are also suitable for musculoskeletal imaging, and they can determine the mechanical properties and state of muscles and tendons. because elastography does not have the same limitations as manual palpation, it is being investigated in some areas for which there is no history of diagnosis with manual palpation. for example, magnetic resonance elastography is capable of assessing the stiffness of the brain, and there is a growing body of scientific literature on elastography in healthy and diseased brains. in 2015, preliminary reports on elastography used on transplanted kidneys to evaluate cortical fibrosis have been published showing promising results. in bristol university's study children of the 90s, 2.5% of 4,000 people born in 1991 and 1992 were found by ultrasound scanning at the age of 18 to have non-alcoholic fatty liver disease; five years later transient elastography found over 20% to have the fatty deposits on the liver of steatosis, indicating non-alcoholic fatty liver disease; half of those were classified as severe. the scans also found that 2.4% had the liver scarring of fibrosis, which can lead to cirrhosis. other techniques include elastography with optical coherence tomography (i.e. light). tactile imaging involves translating the results of a digital "touch" into an image. many physical principles have been explored for the realization of tactile sensors: resistive, inductive, capacitive, optoelectric, magnetic, piezoelectric, and electroacoustic principles, in a variety of configurations. notes †^ in the case of endogenous motion imaging, instead of inducing a disturbance, disturbances naturally created by physiological processes are observed.