In this issue you will find the following; Introduction aboout sound and ultrasound sound wave propertiestypes of wave sound equation peizoelectricity interaction of ultrasound with medium attenuation of ultrasound beamultrasound velocityUltrasound modes A-mode B-mode M-modeImage resolutionUltrasound beam &Ultrasound image formationultrasound image artifactsUltrasound biological effects.