New technologies in clinical ultrasound.

Ultrasound (US) is the imaging modality of choice for a wide variety of clinical indications because of its excellent image quality combined with lack of ionizing radiation, relative portability, and low cost. Numerous advances in US technology over the past fewdecades, such as color and power Doppler, speckle reduction, compound imaging, harmonic imaging, and 3-D imaging have become the standard of care, adding critical information to the US examination. More recently, innovations in US technology, such as elastography, US contrast media, and high-intensity focused ultrasound (HIFU), have been introduced into clinical practice; other new technologies, such as capacitive micromachined ultrasonic transducers (CMUTs) and photoacoustic imaging, are in development and are nearly ready for clinical use. These new and emerging technologies are the subject of this review.