Lesson 07: Ultrasound Transducers This lesson contains 62 slides plus 16 multiple-choice questions. Accompanying text for the slides in this lesson can be found on pages 33 through 42 in the textbook:
Ultrasound Transducers
Ultrasound Transducers
Ultrasound Transducers THE NUMBER OF ACOUSTIC LINES IN A REAL TIME IMAGE: PULSE REPETITION FREQUENCY FRAME RATE
Ultrasound Transducers ACOUSTIC LINES = PRF FRAME RATE PRF FRAME RATE = ACOUSTIC LINES 1000 Hz 10 Hz 100 1000 Hz 20 Hz 50 1500 Hz 10 Hz 150 1500 Hz 20 Hz 75 2000 Hz 10 Hz 200 2000 Hz 20 Hz 100
Ultrasound Transducers ACOUSTIC LINES = PRF FRAME RATE DISPLAY DEPTH PRF CHANCE OF DEPTH AMBIGUITY FRAME RATE ACOUSTIC LINES Increase Decrease Decrease - - Decrease Decrease Increase Increase - Increase Increase Decrease Decrease Increase
Flat-linear array PHOTO OF LINEAR ARRAY CONVENTIONAL LINEAR ARRAY
Flat-linear array PHOTO OF LINEAR ARRAY LINEAR ARRAY SLICE PATTERN
Flat-linear array
Flat-linear array CONVENTIONAL LINEAR ARRAY FETAL IMAGE
Flat-linear array CONVENTIONAL LINEAR ARRAY BREAST IMAGE
Flat-linear array UMBILICAL CORD WITH COLOR DOPPLER
Flat-linear array
Flat-linear array
Flat-linear array
Flat-linear array TRANSMIT FOCAL ZONES THYROID AND LEFT CAROTID
Flat-linear array MULTI-DIMENSIONAL LINEAR ARRAY ELEMENT CONFIGURATION
Flat-linear array
Flat-linear array (Steered) STEERED LINEAR ARRAY VASCULAR IMAGE
Flat-linear array PROSTATE
Curved-linear array (convex array) PHOTO OF CURVED-LINEAR ARRAY
Curved-linear array (convex array) CURVED-LINEAR ARRAY ELEMENT CONFIGURATION
Curved-linear array (convex array) CURVED-LINEAR ARRAY SLICE PATTERN
Curved-linear array (convex array)
Curved-linear array (convex array) LIVER AND RIGHT KIDNEY
Curved-linear array (convex array) ABDOMEN WITH COLOR DOPPLER
Curved-linear array (convex array)
Curved-linear array (convex array)
Curved-linear array (convex array) FIBROID UTERUS
Curved-linear array (convex array) LIVER HEPATIC VESSELS
Curved-linear array (convex array) ASCITES
Curved-linear array (convex array) ENDOVAGINAL PROBE
Sagittal scan planes TRANSABDOMINAL PROBE ENDOVAGINAL PROBE
Curved-linear array (convex array) ENDOVAGINAL UTERUS
Curved-linear array (convex array) PROSTATE IMAGE
Curved-linear array (convex array) NEONATAL BRAIN IMAGE
Curved-linear array (convex array) HANDHELD ULTRASOUND SCANNER
Phased array PHOTO OF PHASED ARRAY
Phased array
Phased array PHASED ARRAY SLICE PATTERN
Phased array
Phased array ABDOMEN
Phased array FETAL HEAD
Phased array
Phased array ENDOVAGINAL UTERUS
Phased array
Phased array CARDIAC IMAGE
Phased array TRANSESOPHAGEAL ECHOCARDIOGRAPHY
Phased array PROSTATE IMAGE
Vector array PHOTO OF VECTOR ARRAY
Vector array VECTOR ARRAY SLICE PATTERN
Vector array ABDOMEN
Vector array HEART, 4-CHAMBER VIEW
Vector array CAROTID ARTERY
Mechanically steered
Mechanical wobbler
Mechanical wobbler SINGLE-ELEMENT ANNULAR ARRAY
Mechanically steered HEPATIC VEINS
Mechanically steered
Mechanically steered EYE, DETACHED RETINA
USB powered CURVED LINEAR ARRAY TRANSDUCER AND USB ADAPTER USB POWERED MECHANICALLY STEERED PROBE
Fluid-delay TRANSDUCER WITH A BUILT-IN FLUID DELAY
Fluid-delay FLAT-LINEAR ARRAY TRANSDUCER WITH A REUSABLE EXTERNAL STAND-OFF PAD
Answers to the following SIXTEEN practice questions were derived from material in the textbook:
Question 1 For a real time image to be flicker-free, what should be the minimum image frame rate? 15 Hz 1000 Hz 1 Hz 100 Hz Page 34
Question 1 For a real time image to be flicker-free, what should be the minimum image frame rate? 15 Hz 1000 Hz 1 Hz 100 Hz Page 34
Question 2 Which parameter is correct if the real time frame rate is 20 Hz? image is updated every 1/1000 second number of acoustic lines is 1000 number of acoustic lines is 20 image is updated every 1/20 second Page 34
Question 2 Which parameter is correct if the real time frame rate is 20 Hz? image is updated every 1/1000 second number of acoustic lines is 1000 number of acoustic lines is 20 image is updated every 1/20 second Page 34
Question 3 If the real time frame rate is increased but the lines per frame are unchanged, what else must happen? imaging depth increases transducer frequency increases the pulse repetition frequency decreases imaging depth decreases Page 34
Question 3 If the real time frame rate is increased but the lines per frame are unchanged, what else must happen? imaging depth increases transducer frequency increases the pulse repetition frequency decreases imaging depth decreases Page 34
Question 4 If the lines per frame changed but the imaging depth remained the same, what else must have changed? frame rate pulse repetition period pulse repetition frequency duty factor Page 34
Question 4 If the lines per frame changed but the imaging depth remained the same, what else must have changed? frame rate pulse repetition period pulse repetition frequency duty factor Page 34
Question 5 If the imaging depth is increased and the sector angle and line density remain the same, what must have taken place? PRF increases frame rate decreases PRP decreases frame rate increases Page 34
Question 5 If the imaging depth is increased and the sector angle and line density remain the same, what must have taken place? PRF increases frame rate decreases PRP decreases frame rate increases Page 34
Question 6 A real time transducer with a frame rate of 10 Hz produces 100 acoustic lines. What occurs if the PRF is unchanged? a higher frame rate will increase the line density a frame rate of 20 Hz will produce 200 acoustic lines the pulse repetition period is 100 milliseconds a frame rate of 20 Hz will produce 50 acoustic lines Page 34
Question 6 A real time transducer with a frame rate of 10 Hz produces 100 acoustic lines. What occurs if the PRF is unchanged? a higher frame rate will increase the line density a frame rate of 20 Hz will produce 200 acoustic lines the pulse repetition period is 100 milliseconds a frame rate of 20 Hz will produce 50 acoustic lines Page 34
Question 7 Which transducer configuration produced the image? flat linear array convex array phased array vector array Pages 35 and 36
Question 7 Which transducer configuration produced the image? flat linear array convex array phased array vector array Pages 35 and 36
Question 8 Which transducer configuration produced the image? flat linear array convex array phased array vector array Pages 39 and 40
Question 8 Which transducer configuration produced the image? flat linear array convex array phased array vector array Pages 39 and 40
Question 9 Which transducer configuration produced the image? flat linear array curved linear array non-curved linear array phased array Pages 37 and 38
Question 9 Which transducer configuration produced the image? flat linear array curved linear array non-curved linear array phased array Pages 37 and 38
Question 10 Which transducer configuration produced the image? flat linear array curved linear array phased array vector array Pages 39 and 40
Question 10 Which transducer configuration produced the image? flat linear array curved linear array phased array vector array Pages 39 and 40
Question 11 Where is dynamic focusing possible? on transducers with frequencies below 5 Hz on transducer arrays on two-element CW Doppler probes on single-element transducers Page 41
Question 11 Where is dynamic focusing possible? on transducers with frequencies below 5 Hz on transducer arrays on two-element CW Doppler probes on single-element transducers Page 41
Question 12 When using a phased array transducer, how is the transmitted sound beam swept? mechanically sweeping the piezoelectric elements mechanically rotating the piezoelectric elements varying the timing of pulses to the individual piezoelectric elements varying the voltage of pulses to the individual piezoelectric elements Page 39
Question 12 When using a phased array transducer, how is the transmitted sound beam swept? mechanically sweeping the piezoelectric elements mechanically rotating the piezoelectric elements varying the timing of pulses to the individual piezoelectric elements varying the voltage of pulses to the individual piezoelectric elements Page 39
Question 13 Which pulsing pattern provides an on-axis beam with focusing? Page 39
Question 13 Which pulsing pattern provides an on-axis beam with focusing? Page 39
Question 14 What does the use of a water path permit? the use of increased output power from the transducer higher frequencies to be used higher pulse repetition frequencies to be used better visualization of superficial structures Page 42
Question 14 What does the use of a water path permit? the use of increased output power from the transducer higher frequencies to be used higher pulse repetition frequencies to be used better visualization of superficial structures Page 42
Question 15 Which element arrangement is only used in mechanically steered transducers? convex array non-curved sequenced array sequenced array annular array Page 41
Question 15 Which element arrangement is only used in mechanically steered transducers? convex array non-curved sequenced array sequenced array annular array Page 41
Question 16 What is the advantage of an annular array over a single element transducer? higher frequencies are possible improved axial resolution greater depth of focus lower cost Page 41
Question 16 What is the advantage of an annular array over a single element transducer? higher frequencies are possible improved axial resolution greater depth of focus lower cost Page 41
END OF LESSON 07 For information on the accompanying textbook, visit the Website: www.sonicorinc.com