This document provides an overview of ultrasound instrumentation and components. It discusses the various transducers used in ultrasound including linear arrays, curved arrays, and mechanical transducers. It also describes the piezoelectric effect, transducer construction, electronic focusing techniques, and display modes. Various ultrasound machine components are also summarized such as the probe, monitor, keyboard, and internal components like the scan converter.

1. Instrumentation & KnobologyMODERATORSDR SURESH MASIMADEDR SHIVANAND MELKUNDI1vaseemali@gmail.com

2. The battle!vaseemali@gmail.com2

3. Why study ultrasoundvaseemali@gmail.com3Bread and butter!

4. comparisionvaseemali@gmail.com4

5. Piezoelectric effect : history1880 piezoelectric effect : Pierre Curie and Jacques Curie.Curie temperature1917, SONAR, Paul Langevin ultrasonic submarine detector.Post World War II :“AT cut” crystal barium titanatelead zirconatetitanatevaseemali@gmail.com5

6. vaseemali@gmail.com6

7. vaseemali@gmail.com7

8. Machine externallyvaseemali@gmail.com8MonitorSpeakerKeyboard Probes CPU

9. Internal componentsvaseemali@gmail.com9

10. Ultrasound gelContentsCarbomerEDTAPropylene glycolTrolamineDon’t adjust gain till gel is appliedApply gel on both sides of plasticWhen nothing is available : use watervaseemali@gmail.com10

11. Transducer orientaionvaseemali@gmail.com11

12. Transducer : piezoelectric effectDirectmechanical force appliedInternal generation of electrical chargeReverseElectrical field appliedinternal generation of a mechanical forcevaseemali@gmail.com12

13. Construction vaseemali@gmail.com13Matching layers

14. Transducer crystal

15. Damping material

16. Casing

17. Cables Matching layersIn front of PZTAcoustic connection b/n skin & PZTDecreases difference in acoustic impedanceLess reflectionMore transmissionvaseemali@gmail.com14

18. Transducer crystalLead zirconatetitanatevaseemali@gmail.com15

19. Damping materialsRubberBack of PZTDecreases Secondary vibrationsvaseemali@gmail.com16

20. Casing & Cables CasingHousing for crystalInsulation from electrical noiseCablesExcite Receive1 wire for 1 elementvaseemali@gmail.com17

21. Thicknessto change f we change transducer .why?any f by applying AC of that fConcept of resonant frequencyvaseemali@gmail.com18

22. Resonant frequencyvaseemali@gmail.com19frequency at which transmits sound most efficientlydepends on disc thicknesswavelength 2x disc thickness

23. Pulsed modeDC appliedDisc expandsA layer is compressedSubsequently adjacent layer compressedCompression wave of v velocityvaseemali@gmail.com20

24. Continuous modeAC voltage appliedCrystal pulsed like pistonCompressions and rarefactionsWavelength Frequency vaseemali@gmail.com21

25. Near field(Fresnel zone) & far field(Fraunhofer zone)Near field : inhomogeneous interferenceFar field : diverges Focal zoneBetween near and far fieldBest resolution vaseemali@gmail.com22

26. Mechanical transducersObsoletePhysically moved for beam steeringUsed in 3D 4DTypes Rotary wheelOscillating transducerOscillating mirrorvaseemali@gmail.com23Diagnostic Ultrasound: Physics and Equipment edited by Peter R. Hoskins, Kevin Martin, Abigail Thrush

27. Rotary wheelOne or more elementsWheel like housingSmall transducer faceIntercostal access vaseemali@gmail.com24

28. Rotary wheelvaseemali@gmail.com25Motor Belttransducers

29. oscillating Drive motorHoused in containerMotor movementElement rotates back & forthvaseemali@gmail.com26

30. Oscillating mirrorElement is stationaryMirror movesDirects beam which movesvaseemali@gmail.com27

31. electronicfocusingMultiple elements usedSeparate electrical supplySequential excitement of elementsTypes Linearcurved2 dimensionalAnnularphased arrayvaseemali@gmail.com28

32. Electronic focusingMounted on straight barElectronic pulsingFocal depthFocus at many FLGreater time delay b/n elements=shorter focal lengthvaseemali@gmail.com29

33. Multiple zone focusing2 focal zonesFocused in 2 pulsesFirst one focused at f1Second at f2vaseemali@gmail.com30

34. Linear VS Curved arrayLinear curvedLarger area of pt contactWide field near the skinBetter quality imageSuperficial structuresSmall acoustic windowNarrow field near skinWide field at depthDetailing is lessvaseemali@gmail.com31

35. Evolution of arraysvaseemali@gmail.com32Medical imaging: principles, detectors, and electronics By Krzysztof Iniewski

36. 1.5 D arrayMultiple(5-7) linear arraysBeam steering in Azimuthal planePhased : outer to innerFrame rate reductionvaseemali@gmail.com33The essential physics of medical imaging By Jerrold T. Bushberg

37. 2D arrayMultiple rows of elementsVoxel instead of pixelObstetricsvaseemali@gmail.com34

38. 2d arraysvaseemali@gmail.com35

39. Annular arrayElements in concentric ringsvaseemali@gmail.com36

40. Linear VS phased arrayvaseemali@gmail.com37

41. Phased arrayElements pulsed as groups Small time delaysPulsed by processorvaseemali@gmail.com38

42. Phased arrayvaseemali@gmail.com39

43. Endorectal vaseemali@gmail.com40360 degree radial rectal transducer.Main SpecificationsArray Type: Mechanical RadialScan angle: 360ºFrequency range: 7.5/10 MHz

44. endovaginalvaseemali@gmail.com41Array type: Convex ArrayScan angle: 120°Radius: 14 mmFrequency range: 3-7.5 MHz

45. “T" Style Intraoperativevaseemali@gmail.com42Array Type: Linear ArrayScan angle/width: 42mmFrequency range: 5-10 MHz

46. "I" Style Finger-Grip intraopvaseemali@gmail.com43design 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 Laparoscopicvaseemali@gmail.com44End-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 Surgeryvaseemali@gmail.com45pediatric scanning CBD scanning. small vessels Array Type: Linear ArrayInsertion diameter: 10mmScan angle/width: 10mmFrequency range: 5-13 MHz

49. Motorized TEEvaseemali@gmail.com46cardiac anesthesia, cardiac surgery, or intensive care workArray type: Phased Array SectorScan angle: 90°Frequency range: 2-8 MHzInsertion Depth: 1000 mmDiameter: 12.5 mm

50. 38mm for Regional Anesthesiavaseemali@gmail.com47slightly larger footprint 38mm

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 Arrayvaseemali@gmail.com48Cardiac transducer Array type: Phased ArrayScan angle: 90°Frequency range: 2.5-5 MHz

57. intravascularvaseemali@gmail.com49Atheromatous plaqueAfter stenting

58. image displayvaseemali@gmail.com50

59. image displayvaseemali@gmail.com51Manufacturer

60. image displayvaseemali@gmail.com52Date/time

61. image displayvaseemali@gmail.com53Clinic info

62. image displayvaseemali@gmail.com54Patient info

63. image displayvaseemali@gmail.com55Profile / Preset

64. image displayvaseemali@gmail.com56Transducer in use

65. gainDegree of echo amplificationBightness of displayMeasured in dbMore : artifactual echoesLess : negates real echo infovaseemali@gmail.com57Gain

66. image displayvaseemali@gmail.com58Map/smooth/persist

67. image displayvaseemali@gmail.com59depth

68. Annotation vaseemali@gmail.com60Annotation

69. Image tintingvaseemali@gmail.com61Golden hue is aesthetically pleasing to the eye

70. Shows excellent shadows and highlights. Left right invertvaseemali@gmail.com62

71. Up down invertvaseemali@gmail.com63

72. Split framevaseemali@gmail.com64Display 2 images side by sideComparison of echotexture

73. Modes of image display65vaseemali@gmail.com

74. A modeOphthalmic examPrecise length & depth measurementsTransducer : line of sightPosition of structure : XStrength of backscatter vaseemali@gmail.com66Amplitude of backscatterTime/distance

75. B modevaseemali@gmail.com67Brightnessα intensity of echoPosition in tissue α position on screen

76. M modeBrightness α intensity of reflected signalPosition of moving reflectorsRapid motion : cardiac valvesvaseemali@gmail.com68Essentials of medical ultrasound: a practical introduction to the principles By Michael H. Repacholi, Dierdre A. Benwell

77. M modevaseemali@gmail.com69The essential physics of medical imaging By Jerrold T. Bushberg

78. M modeECG concurrentLine of sightvaseemali@gmail.com70

79. Real time USGSuccession of framesMotion of tissuesLine densityat least 100 per frameFrame rateDepth of viewvaseemali@gmail.com71

80. Frame rateMovie FR 25-30fpsTemporal resolutionNow >100 fps, TR 10msReal time 20-30fpsM mode : very high fpsHence LOS ,TR 0.1msBetter frame rateLess depthLess field of viewDepth X scan lines X frame rate =constantvaseemali@gmail.com72

81. Calipers/measureLengthArea Volume vaseemali@gmail.com73Calipers

82. Trackball Cursor motionGUI controlvaseemali@gmail.com74Track ball

83. ZoomMagnifies selected areaRead zoomDigital zoomNo changes in line densityWrite zoomOptical zoomIncreases scan line densityImproved resolutionvaseemali@gmail.com75

84. image displayvaseemali@gmail.com76Dynamic range Compress

85. Dynamic range/compressRatio of largest/smallest echoMeasured in dBFrom tissues 100-150dBDecreases as signals into USGRejection filter : rejects very small & very large echoesTGC60 dB at ADC level vaseemali@gmail.com77

86. Compress 60dB of interestDisplay : only 20dB brightness levelsNon linear amplifierMore gain for smaller signalsLiver texture: wide Obstetric: less Dark : amniotic fluidBright : bones vaseemali@gmail.com78

87. Power vaseemali@gmail.com79

88. Power Not the same as gainEnergy transferred to tissuesMore power : more tissue damageMeasured in watts/cm2ALARA : as low as reasonably allowableMore than 8 W/cm2 : therapeuticAIUM guidelines(SATA,SPTP)Doppler : excessive power levelsUse less powerQuick examinationvaseemali@gmail.com80

89. Gain vaseemali@gmail.com81Overall “brightness”Changes echo strength over entire image

90. Time gain compensationEach slider for a range of depthTop : superficialBottom : deepButtons at Center : average gainvaseemali@gmail.com82

91. Time gain compensationvaseemali@gmail.com83

92. Time gain compensationvaseemali@gmail.com84Springer handbook of acoustics By Thomas D. Rossing

93. Freeze and cine loopStops further image acquisitionDisplays current image vaseemali@gmail.com85

94. Cine loopTrack ballNot USG specificUsed in CT MRI PETStill images in successionPlayed back Dynamic movement :Cardiac motionDoppler studiesRecorded as moviePhysician/cardiologist can view latervaseemali@gmail.com86

95. Image processorInterpolation between scan linesLog compressPost processingSpatial filteringReduce noiseEnhance edgesTemporal filtering : frame avg/persistReduces image noiseImage demonstrates a lagReduction in temporal resolutionvaseemali@gmail.com87

96. Scan converter (ADC)Echo : Analog waveAnalogueStorage CRTUnstable“drift” in settingsAnalog-Digital convertorDigital StableProcessingvaseemali@gmail.com88

97. Image displayDisplays : analogue inputModern machines: digital architectureDAC Input : digitalOutput : analogueBrightness Contrast vaseemali@gmail.com89

98. Image memory640 X 480 pixels256 gray shade levels¼ MB per imageColor images : Doppler imagingFreeze functionTemporary image storeArchiving : MLC Latest systems : internal storageHold many GB datavaseemali@gmail.com90

99. Image resolutionSpatial : 2 close objects as distinctAxial : along beam axisLateral : perpendicular to beam axisAzimuthal : perpendicular to beam & transducerContrast : two regions of different avg brightnessTemporal : distinguish events in timeReal time cant in cardiac valve motionFreedom from artifactsvaseemali@gmail.com91

100. Spatial resolutionvaseemali@gmail.com92elevationlateralaxialMedical imaging: principles, detectors, and electronics By Krzysztof Iniewski

101. Tickle UR brain!Why does the high frequency superficial probe have a high resolutionvaseemali@gmail.com93

102. Axial resolutionvaseemali@gmail.com94SPL=no of cycles X wavelengthThe essential physics of medical imaging By Jerrold T. Bushberg

103. Axial resolution95Ultrasound in cardiology By Kurt J. G. Schmailzl, Oliver Ormerodvaseemali@gmail.com

104. Lateral resolutionDepends on Beam widthUser controlledDepends on focusingvaseemali@gmail.com96The essential physics of medical imaging By Jerrold T. Bushberg

105. Azimuthal/elevation resolutionResolution in planePerpendicular to beam axisPerpendicular to transducerThickness of beamNo user controlFixed due to transducer thicknessvaseemali@gmail.com97