Ultrasound is defined as sound a frequency above the upper length of normal hearing (ULKHZ)
Ultrasound image are formed from the reflected sound waves(2.5-30 MHz ). Sound waves are generated in the bent by B-node the transduce (probe)Those sound waves are effected by interfaces of tissue c different physical properties and reflected electrons is used to generate the contrast of the different tissue to form a image.
USG generate realtime 2D image at a rate of 15-60 frames per second of both anatomy and a motion.
Heart and neck the probes of 7.5 MHz or generate are used.
USG produce diagnostic information a high degree of accuracy.
Ultra sound allows a gold standard ability to determine whether a focal lesion is cystic solid even better than CT and MU.
Ultrasound has no ionizing radiation, heater readily addible and relatively cheap.
It plays an important role in guiding intervention procedure such as FNAC, biopsies, catheters accurately and in real time.