1. Instrumentation & Knobology MODERATORS DR SURESH MASIMADEDR SHIVANAND MELKUNDI 1 vaseemali@gmail.com

2. The battle! vaseemali@gmail.com 2

3. Why study ultrasound vaseemali@gmail.com 3 Bread and butter!

4. comparision vaseemali@gmail.com 4

5. Piezoelectric effect : history 1880 piezoelectric effect : Pierre Curie and Jacques Curie. Curie temperature 1917, SONAR, Paul Langevin ultrasonic submarine detector. Post World War II : “AT cut” crystal barium titanate lead zirconatetitanate vaseemali@gmail.com 5

6. vaseemali@gmail.com 6

7. vaseemali@gmail.com 7

8. Machine externally vaseemali@gmail.com 8 Monitor Speaker Keyboard Probes CPU

9. Internal components vaseemali@gmail.com 9

10. Ultrasound gel Contents Carbomer EDTA Propylene glycol Trolamine Don’t adjust gain till gel is applied Apply gel on both sides of plastic When nothing is available : use water vaseemali@gmail.com 10

11. Transducer orientaion vaseemali@gmail.com 11

12. Transducer : piezoelectric effect Direct mechanical force applied Internal generation of electrical charge Reverse Electrical field applied internal generation of a mechanical force vaseemali@gmail.com 12

14. Transducer crystal

15. Damping material

16. Casing

18. Transducer crystal Lead zirconatetitanate vaseemali@gmail.com 15

19. Damping materials Rubber Back of PZT Decreases Secondary vibrations vaseemali@gmail.com 16

20. Casing & Cables Casing Housing for crystal Insulation from electrical noise Cables Excite Receive 1 wire for 1 element vaseemali@gmail.com 17

21. Thickness to change f we change transducer .why? any f by applying AC of that f Concept of resonant frequency vaseemali@gmail.com 18

22. Resonant frequency vaseemali@gmail.com 19 frequency at which transmits sound most efficiently depends on disc thickness wavelength 2x disc thickness

23. Pulsed mode DC applied Disc expands A layer is compressed Subsequently adjacent layer compressed Compression wave of v velocity vaseemali@gmail.com 20

24. Continuous mode AC voltage applied Crystal pulsed like piston Compressions and rarefactions Wavelength Frequency vaseemali@gmail.com 21

25. Near field(Fresnel zone) & far field(Fraunhofer zone) Near field : inhomogeneous interference Far field : diverges Focal zone Between near and far field Best resolution vaseemali@gmail.com 22

26. Mechanical transducers Obsolete Physically moved for beam steering Used in 3D 4D Types Rotary wheel Oscillating transducer Oscillating mirror vaseemali@gmail.com 23 Diagnostic Ultrasound: Physics and Equipment edited by Peter R. Hoskins, Kevin Martin, Abigail Thrush

27. Rotary wheel One or more elements Wheel like housing Small transducer face Intercostal access vaseemali@gmail.com 24

28. Rotary wheel vaseemali@gmail.com 25 Motor Belt transducers

29. oscillating Drive motor Housed in container Motor movement Element rotates back & forth vaseemali@gmail.com 26

30. Oscillating mirror Element is stationary Mirror moves Directs beam which moves vaseemali@gmail.com 27

31. electronicfocusing Multiple elements used Separate electrical supply Sequential excitement of elements Types Linear curved 2 dimensional Annular phased array vaseemali@gmail.com 28

32. Electronic focusing Mounted on straight bar Electronic pulsing Focal depth Focus at many FL Greater time delay b/n elements=shorter focal length vaseemali@gmail.com 29

33. Multiple zone focusing 2 focal zones Focused in 2 pulses First one focused at f1 Second at f2 vaseemali@gmail.com 30

34. Linear VS Curved array Linear curved Larger area of pt contact Wide field near the skin Better quality image Superficial structures Small acoustic window Narrow field near skin Wide field at depth Detailing is less vaseemali@gmail.com 31

35. Evolution of arrays vaseemali@gmail.com 32 Medical imaging: principles, detectors, and electronics By Krzysztof Iniewski

36. 1.5 D array Multiple(5-7) linear arrays Beam steering in Azimuthal plane Phased : outer to inner Frame rate reduction vaseemali@gmail.com 33 The essential physics of medical imaging By Jerrold T. Bushberg

37. 2D array Multiple rows of elements Voxel instead of pixel Obstetrics vaseemali@gmail.com 34

38. 2d arrays vaseemali@gmail.com 35

39. Annular array Elements in concentric rings vaseemali@gmail.com 36

40. Linear VS phased array vaseemali@gmail.com 37

41. Phased array Elements pulsed as groups Small time delays Pulsed by processor vaseemali@gmail.com 38

42. Phased array vaseemali@gmail.com 39

43. Endorectal vaseemali@gmail.com 40 360 degree radial rectal transducer. Main SpecificationsArray Type: Mechanical RadialScan angle: 360ºFrequency range: 7.5/10 MHz

44. endovaginal vaseemali@gmail.com 41 Array type: Convex ArrayScan angle: 120°Radius: 14 mmFrequency range: 3-7.5 MHz

45. “T" Style Intraoperative vaseemali@gmail.com 42 Array Type: Linear ArrayScan angle/width: 42mmFrequency range: 5-10 MHz

46. "I" Style Finger-Grip intraop vaseemali@gmail.com 43 design fits comfortably between the index and middle finger which allows for palpating organs and scanning at the same time. Array Type: Convex ArrayScan angle/width: 65°/20mmFrequency range: 3.75-10 MHz

47. End Fire Laparoscopic vaseemali@gmail.com 44 End-fire laparoscopic transducer that is perfect for CBD scanning and targeting lesions. Array Type: Phased ArrayScan angle/width: 90°Frequency range: 3-7.5 MHz

48. Micro Surgery vaseemali@gmail.com 45 pediatric scanning CBD scanning. small vessels Array Type: Linear ArrayInsertion diameter: 10mmScan angle/width: 10mmFrequency range: 5-13 MHz

49. Motorized TEE vaseemali@gmail.com 46 cardiac anesthesia, cardiac surgery, or intensive care work Array type: Phased Array SectorScan angle: 90°Frequency range: 2-8 MHzInsertion Depth: 1000 mmDiameter: 12.5 mm

51. visualization of deeper structures

52. nerves

53. Infraclavicular

54. popliteal regions.

55. guide needle placement Main SpecificationsArray Type: Convex ArrayScan angle/width: 38mmFrequency range: 5-10MHz

56. Cardiac Phased Array vaseemali@gmail.com 48 Cardiac transducer Array type: Phased ArrayScan angle: 90°Frequency range: 2.5-5 MHz

57. intravascular vaseemali@gmail.com 49 Atheromatous plaque After stenting

58. image display vaseemali@gmail.com 50

59. image display vaseemali@gmail.com 51 Manufacturer

60. image display vaseemali@gmail.com 52 Date/time

61. image display vaseemali@gmail.com 53 Clinic info

62. image display vaseemali@gmail.com 54 Patient info

63. image display vaseemali@gmail.com 55 Profile / Preset

64. image display vaseemali@gmail.com 56 Transducer in use

65. gain Degree of echo amplification Bightness of display Measured in db More : artifactual echoes Less : negates real echo info vaseemali@gmail.com 57 Gain

66. image display vaseemali@gmail.com 58 Map/smooth/persist

67. image display vaseemali@gmail.com 59 depth

68. Annotation vaseemali@gmail.com 60 Annotation

71. Up down invert vaseemali@gmail.com 63

72. Split frame vaseemali@gmail.com 64 Display 2 images side by side Comparison of echotexture

73. Modes of image display 65 vaseemali@gmail.com

74. A mode Ophthalmic exam Precise length & depth measurements Transducer : line of sight Position of structure : X Strength of backscatter vaseemali@gmail.com 66 Amplitude of backscatter Time/distance

75. B mode vaseemali@gmail.com 67 Brightnessα intensity of echo Position in tissue α position on screen

76. M mode Brightness α intensity of reflected signal Position of moving reflectors Rapid motion : cardiac valves vaseemali@gmail.com 68 Essentials of medical ultrasound: a practical introduction to the principles By Michael H. Repacholi, Dierdre A. Benwell

77. M mode vaseemali@gmail.com 69 The essential physics of medical imaging By Jerrold T. Bushberg

78. M mode ECG concurrent Line of sight vaseemali@gmail.com 70

79. Real time USG Succession of frames Motion of tissues Line density at least 100 per frame Frame rate Depth of view vaseemali@gmail.com 71

80. Frame rate Movie FR 25-30fps Temporal resolution Now >100 fps, TR 10ms Real time 20-30fps M mode : very high fps Hence LOS ,TR 0.1ms Better frame rate Less depth Less field of view Depth X scan lines X frame rate =constant vaseemali@gmail.com 72

81. Calipers/measure Length Area Volume vaseemali@gmail.com 73 Calipers

82. Trackball Cursor motion GUI control vaseemali@gmail.com 74 Track ball

83. Zoom Magnifies selected area Read zoom Digital zoom No changes in line density Write zoom Optical zoom Increases scan line density Improved resolution vaseemali@gmail.com 75

84. image display vaseemali@gmail.com 76 Dynamic range Compress

85. Dynamic range/compress Ratio of largest/smallest echo Measured in dB From tissues 100-150dB Decreases as signals into USG Rejection filter : rejects very small & very large echoes TGC 60 dB at ADC level vaseemali@gmail.com 77

86. Compress 60dB of interest Display : only 20dB brightness levels Non linear amplifier More gain for smaller signals Liver texture: wide Obstetric: less Dark : amniotic fluid Bright : bones vaseemali@gmail.com 78

87. Power vaseemali@gmail.com 79

88. Power Not the same as gain Energy transferred to tissues More power : more tissue damage Measured in watts/cm2 ALARA : as low as reasonably allowable More than 8 W/cm2 : therapeutic AIUM guidelines(SATA,SPTP) Doppler : excessive power levels Use less power Quick examination vaseemali@gmail.com 80

89. Gain vaseemali@gmail.com 81 Overall “brightness” Changes echo strength over entire image

90. Time gain compensation Each slider for a range of depth Top : superficial Bottom : deep Buttons at Center : average gain vaseemali@gmail.com 82

91. Time gain compensation vaseemali@gmail.com 83

92. Time gain compensation vaseemali@gmail.com 84 Springer handbook of acoustics By Thomas D. Rossing

93. Freeze and cine loop Stops further image acquisition Displays current image vaseemali@gmail.com 85

94. Cine loop Track ball Not USG specific Used in CT MRI PET Still images in succession Played back Dynamic movement : Cardiac motion Doppler studies Recorded as movie Physician/cardiologist can view later vaseemali@gmail.com 86

95. Image processor Interpolation between scan lines Log compress Post processing Spatial filtering Reduce noise Enhance edges Temporal filtering : frame avg/persist Reduces image noise Image demonstrates a lag Reduction in temporal resolution vaseemali@gmail.com 87

96. Scan converter (ADC) Echo : Analog wave Analogue Storage CRT Unstable “drift” in settings Analog-Digital convertor Digital Stable Processing vaseemali@gmail.com 88

97. Image display Displays : analogue input Modern machines: digital architecture DAC Input : digital Output : analogue Brightness Contrast vaseemali@gmail.com 89

98. Image memory 640 X 480 pixels 256 gray shade levels ¼ MB per image Color images : Doppler imaging Freeze function Temporary image store Archiving : MLC Latest systems : internal storage Hold many GB data vaseemali@gmail.com 90

99. Image resolution Spatial : 2 close objects as distinct Axial : along beam axis Lateral : perpendicular to beam axis Azimuthal : perpendicular to beam & transducer Contrast : two regions of different avg brightness Temporal : distinguish events in time Real time cant in cardiac valve motion Freedom from artifacts vaseemali@gmail.com 91

100. Spatial resolution vaseemali@gmail.com 92 elevation lateral axial Medical imaging: principles, detectors, and electronics By Krzysztof Iniewski

101. Tickle UR brain! Why does the high frequency superficial probe have a high resolution vaseemali@gmail.com 93

102. Axial resolution vaseemali@gmail.com 94 SPL=no of cycles X wavelength The essential physics of medical imaging By Jerrold T. Bushberg

103. Axial resolution 95 Ultrasound in cardiology By Kurt J. G. Schmailzl, Oliver Ormerod vaseemali@gmail.com

104. Lateral resolution Depends on Beam width User controlled Depends on focusing vaseemali@gmail.com 96 The essential physics of medical imaging By Jerrold T. Bushberg

105. Azimuthal/elevation resolution Resolution in plane Perpendicular to beam axis Perpendicular to transducer Thickness of beam No user control Fixed due to transducer thickness vaseemali@gmail.com 97

106. image display vaseemali@gmail.com 98 Mechanical index

107. image display vaseemali@gmail.com 99 Thermal index

108. safety Thermal index Mechanical index vaseemali@gmail.com 100

109. Thank you vaseemali@gmail.com 101

110. vaseemali@gmail.com 102

111. vaseemali@gmail.com 103

112. vaseemali@gmail.com 104

113. References Principles and Practice of Ultrasonography By Bhargava Doppler Ultrasound in Gynecology and Obstetrics By ChristofSohn, Hans-Joachim Voigt, Klaus Vetter, Klaus Vetter (M.D.) Small animal diagnostic ultrasound By Thomas G. Nyland, John S. Matto Clinical sonography: a practical guide By Roger C. Sanders, Thomas Charles Winter on Clinical diagnostic ultrasound By Grant M. Baxter, Paul L. P. Allan, Patricia Morley PACS and Imaging Informatics: Basic Principles and Applications By H. K. Huang Medical imaging physics By William R. Hendee, E. Russell Ritenour The essential physics of medical imaging By Jerrold T. Bushberg Appleton & Lange's review for the ultrasonography examination By Carol Krebs, Charles S. Odwin, Arthur C. Fleischer Advances in mass data analysis of images and signals in medicine ... By Petra Perner The practice of ultrasound: a step-by-step guide to abdominal scanning By Berthold Block Diagnostic ultrasound imaging: inside out By Thomas L. Szabo vaseemali@gmail.com 105