1. ULTRA SOUND IN MEDICAL IMAGING Mohammad Amir Final Year MBBS JJMMC

2. WHAT IS MEDICAL IMAGING ?

3. MEDICAL IMAGING: The techniques and processes used to create image of the internal as well as external human body parts for clinical purpose .

5. It makes a surgical targets more clear and precise

6. It provides a pictorial status of fetus development right from 4th weak to 36th- 38th week

8. MAMOGRAPHY

9. CONTRAST RADIOGRAPHY

10. ULTRA SOUND

11. CT SCAN

12. MRI

13. SPECT(SINGLE PHOTON EMMISION TOMOGRAPHY)

15. SONAR was first time used in war time 1940

22. Sound interaction with soft tissues= bio effect

24. TISSUE INTRACTION WITH SOUND = ACOUSTIC PROPAGATION PROPERTIES

25. ECHOES ARE RECEIVED BY THE TRANSDUCER CRYSTAL

29. WAVELENGTH

30. BANDWIDTH

31. ATTENUATION

33. FREQUENCY AND RESOLUTION HIGH FREQUENCY = HIGH RESOLUTION

34. DYNAMIC RANGE

35. M-MODE B-MODE

36. Power Doppler Color Doppler

38. Diskstorage device

41. Transducer Design Size, design and frequency depend upon the examination

43. Brightness of the dots is proportional to the strength of the returning echoes

44. Location of the dots is determined by travel time. The velocity in tissue is assumed constant at 1540m/sec

47. greater  of the AI = more signal reflected

49. Ultrasound Gain Gain controls receiver gain only does NOT change power output think: stereo volume Increase gain = brighter Decrease gain = darker

50. Balanced Gain Gain settings are important to obtaining adequate images. bad far field bad near field balanced

51. Reflected Echo’s Strong Reflections = White dots Diaphragm, tendons, bone ‘Hyperechoic’

52. Reflected Echo’s Weaker Reflections = Grey dots Most solid organs, thick fluid – ‘isoechoic’

53. Reflected Echo’s No Reflections = Black dots Fluid within a cyst, urine, blood ‘Hypoechoic’ or echofree

54. Ultrasound Beam Profile Beam comes out as a slice Beam Profile Approx. 1 mm thick Depth displayed – user controlled Image produced is “2D” tomographic slice assumes no thickness You control the aim 1mm

55. Goal of an Ultrasound System The ultimate goal of any ultrasound system is to make like tissues look the same and unlike tissues look different

56. Accomplishing this goal depends upon... Resolving capability of the system axial/lateral resolution spatial resolution contrast resolution temporal resolution Processing Power ability to capture, preserve and display the information

57. Ultrasound Applications Visualisation Tool: Nerves, soft tissue masses Vessels - assessment of position, size, patency Ultrasound Guided Procedures in real time – dynamic imaging; central venous access, nerve blocks

58. Imaging Know your anatomy – Skin, muscle, tendons, nerves and vessels Recognise normal appearances – compare sides!

59. Skin, subcutaneous tissue Epidermis Loose connective tissue and subcutaneous fat is hypoechoic Muscle interface Muscle fibres interface Bone

64. Dynamic technique