While not visible on conventional grayscale ultrasound (left), a strain<unk>  image (centre) of the prostate gland detects a cancer (dark red area at lower left). The finding is confirmed by histology.<unk>  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<unk>  is completely noninvasive.<unk>  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.<unk>  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,<unk>  sees use for organs and diseases where manual palpation was already widespread.<unk>  is used for detection and diagnosis of breast, thyroid, and prostate cancers. Certain types of<unk>  are also suitable for musculoskeletal imaging, and they can determine the mechanical properties and state of muscles and tendons. Because<unk>  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<unk>  is capable of assessing the stiffness of the brain, and there is a growing body of scientific literature on<unk>  in healthy and diseased brains. Preliminary reports on<unk>  used on transplanted kidneys to evaluate cortical fibrosis have been published showing promising results.
Elastography
Digital variance angiography
Microangiography
Strain rate imaging
Ankle–brachial pressure index
Venography
Digital subtraction angiography
Intravascular imaging