Outlines requirements and time allocation Display Mode ional imaee the verticalaxis and the time(distance)along the horizontalaxis n time or distance it takes the beam n thethe tall the ampld ike wi appe oement. Two-dimensional utrasound varying the brightness of a dot to correspond to echo strength Gray scale refers to the condition of assigning each level of amplitude a particular shade of ond over sele d are 1 body.The frame rate is dependent on the frequency and Three-Dimensional Reconstruction Images are acquired o onhery.andz axies,manually realigned,and then reonructed the fetal face.ankleand extremities in the second-and third trimester fetus. and extremities in the s third 20 Spectral Doppler: ) Color Doppler Flow Imaging (CDFI) high-velocity flows and useful in cardioloy pler 上(P)Doppler edr or os and has one aysal that pules to listens or receive the returning signa A Doppler sound beam is sent and received intermittently with one transducer distance,the depth of the site sampled is known. PW Doppler isused for lower flows 6 6 Outlines, requirements and time allocation Display Mode A-Mode (Amplitude Modulation). A-mode ,or amplitude modulation, produces a one-dimensional image displaying the amplitude strength of the returning echo signals along the vertical axis and the time (distance) along the horizontal axis. The amplitude display represents the time or distance it takes the beam to strike an interface and return the signal to the transducer. The greater the reflection at the interface , the taller the amplitude spike will appear M-Mode (Motion Mode) The M-mode , or motion mode, displays time along the horizontal axis and depth along the vertical axis to depict movement , especially in cardiac structures B-Mode( Brightness Modulation) . Gray scale ultrasound Section ultrasound Two- dimensional ultrasound The B-mode is the basis for all real-time imaging in ultrasound. The B-mode, or brightness modulation, method display the intensity (amplitude) of an echo by varying the brightness of a dot to correspond to echo strength Gray scale refers to the condition of assigning each level of amplitude a particular shade of gray . Real-time. Real-time imaging provides a dynamic presentation of multiple image frame per second over selected areas of the body. The frame rate is dependent on the frequency and depth of the transducer and depth selection. Three –Dimensional Reconstruction Images are acquired on their x,y,and z axies, manually realigned , and then reconstructed into a three dimensional format. This technique has been useful in reconstructing the fetal face, ankle , and extremities in the second –and third trimester fetus. Clinical investigations are currently underway to discover additional applications of three-dimensional imaging. Three –Dimensional Reconstruction has been useful in reconstructing the fetal face, ankle , and extremities in the second –and third trimester fetus. Doppler Ultrasound Spectral Doppler : Continuous Wave Doppler (CW) Pulsed Wave Doppler (PW) Color Doppler Flow Imaging (CDFI) Power Doppler Continuous Wave (CW) Doppler Continuous wave (CW) Doppler contains two piezoelectric elements-one for sending and one for receiving. CW is used for high-velocity flows and especially useful in cardiology Pulsed wave ( PW) Doppler Pulsed wave ( PW) Doppler is used for lower flows and has one crystal that pulses to transmit the signal and also listens or receive the returning signal. Pulsed Wave (CW) Doppler ⚫ A Doppler sound beam is sent and received intermittently with one transducer over a short period of time. ⚫ Since the time that the Doppler signal takes to reach the target can be converted to distance, the depth of the site sampled is known. ⚫ PW Doppler is used for lower flows 20’