MFEL Ultrasound in Medicine Part 2 Ultrasound imaging in 2D and 3D

Transcription

1 MFEL 3010 Ulrasound in Medicine Par 2 Ulrasound imaging in 2D and 3D Hans Torp Deparmen of Circulaion and Medical Imaging NTNU Hans Torp NTNU, Norway

2 Ulrasound in Medicine Lecure 1, Sepember 19h: Overview and basic principles Lecure 2, Ocober 3rd: Ulrasound imaging in 2D and 3D Lecure 3, Ocober 24h: Ulrasound blood flow velociy measuremens Hans Torp NTNU, Norway

3 Ulrasound imaging in 2D and 3D Ulrasound 2D imaing Ulrasound 3D imaging Pocke size ulrasound Demo Hans Torp NTNU, Norway

4 Ulralyd probe Fokusering Syring og fokusering elemener

5 Beamforming Transmi Receive Delays Transmi Signal Aligned receive signals Delays lambda/2 lambda/2 Focal Poin Scaerer a Focal Poin 5 of 45 Couresy of Kjell Krisoffersen and Tore Bjåsad

6 Received Echoes from poin sources 1 2 probe elemens Objecs

7 Digial Beam Former A / D A / D A / D A / D #Channels: 100 A / D A / D A / D # digis per echo signal: Daa per scanline: 3 M byes Daa per image: 150 M byes Daa per second: 1200 M byes

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9 Transmission and reflecion 9 of 45

10 Transmission and reflecion 10 of 45

11 Ulrasonic bio-effecs Thermal effecs Local and emporal emperaure increase Physioerapy: Heaing of muscular issue Thermal indeks TI = emperaure increase (cendegree). Recommendaion: TI < 3 Mechanical effecs: Excessive vibraions may cause caviaion Therapy: Kidney sone disinegraion Mechanical Index MI. Recommendaion: MI < 1.9 Diagnosic ulrasound is safe as long as MI and TI are kep below recommended limis Hans Torp NTNU, Norway

12 Why do we wan o increase acousical power in ulrasound diagnosis? - Increased sensiiviy in Doppler bloodflow measuremens - Generae non-linear waves which can improve image qualiy (harmonic imaging) Hans Torp NTNU, Norway

13 Cardiac ulrasound imaging Acousical noise due o - reverberaions - aberraions

14 Non-linear acousics in Ulrasound Imaging Transducer x x 10-6 Body wall objec Hans Torp NTNU, Norway

15 Harmonic disorion eksraced by a band-pass filer Fundamenal Hans Torp NTNU, Norway Signal from sepum Noise from LV caviy 2. harmonic

16 The hear is a pump Pump oupu no saisfacory? Diagnosis: wha is wrong? Funcional or anaomical Anaomy: leaking valves? Regional funcion: how well is each muscle cell conracing? 16 of 45

17 3D Cardiac Ulrasound 17 of 45 Figure by Terry Hayes

18 Why 3D? Visualizaion of anaomic disorders No shape-assumpions No ou-of-plane Arbirary 2D slices from 3D daase Decreased exam ime 18 of 45 Videos by Crosby and Jungwirh e al

19 Beamforming Transmi Receive Delays Transmi Signal Aligned receive signals Delays lambda/2 lambda/2 Focal Poin Scaerer a Focal Poin 19 of 45 Couresy of Kjell Krisoffersen and Tore Bjåsad

20 2-D marix array probe From 1D Array o 2D Array array elemens array elemens Azimuh Elevaion 20 of 45

21 Cardiac real ime 3D wih elecronically seered beams Mus fi beween ribs Mainain image qualiy (aperure size) Squared number of channels (64 2 =4096) Squared number of beams 21 of 45

22 Fully sampled 2D array Enabling echnologies Manufacure Inerconnec Inegraed elecronics Pos processing Very small elemens: high impedance 2D sysem, 64 channels: 12bi/sample*40MHz*64=3.8Gb/s 3D sysem, 2048 channels: 12bi/sample*40MHz*2048=123Gb/s 22 of 45 Couresy of Philips Medical and GE Vingmed

23 Sub-aperures 1D Projecion Spli array ino subaperures Sysem Delays Probe processing ~2 * lambda Micro-beamforming in probe handle Channel coun reduced from ~3000 o ~ of 45 couresy of Kjell Krisoffersen

24 Real ime challenges Speed of sound Wide beams Fewer beams Inrinsic radeoff beween high image qualiy and high frame rae 2D: 100 beams / 5000 Hz = 20ms. 3D: beams / 5000 Hz = 2s. Framerae = 50Hz Framerae = 0.5Hz 24 of 45 Video by Jonas Crosby

25 Parallel beams Increase frame rae Mus reduce Tx aperure Looses peneraion and resoluion Harmonic imaging problemaic Image arifacs 25 of 45

26 Example: Healhy colleague. Trans-horacic probe Thomas? 26 of 45

27 Real-ime volume measuremen (RCTL) 27 of 45 couresy of Fredrik Orderud

28 Example: Barlow miral valve disease pre-op. Transesophageal probe 28 of 45 video by Philips Healhcare

29 Example: Barlow miral valve disease pos-op. 29 of 45 video by Philips Healhcare

30 Hear aack 30 of 45 US Naional Hear, Lung, and Blood Insiue, Diseases and Condiions Index

31 Evaluaing myocard funcion Hear muscle no funcioning properly Conraciliy / force: ideal parameer Perfusion We ypically measure displacemen (and derived properies velociy, srain, srain rae) Conracing cardiac muscle cell 31 of 45 Videos by Moren Høydal and Hans Torp

32 9-slice Easier o visually assess wall moion in cu-planes han wih 3D rendering 32 of 45 Illusraion by GE Vingmed Ulrasound

33 Subsanial reducion in size and power consumpion Minor difference in image qualiy 250 kg 0.38 kg 2000 W 10 W

34 34 Fully sampled 2D array Enabling echnologies Manufacure Inerconnec Inegraed elecronics Pos processing Very small elemens: high impedance 2D sysem, 64 channels: 12bi/sample*40MHz*64=3.8Gb/s 3D sysem, 2048 channels: 12bi/sample*40MHz*2048=123Gb/s Couresy of Philips Medical and GE Vingmed

35 35 Vscan inroduced by GE s CEO Jeff Immel 20h Ocober 2009 Developed a GE-Vingmed ulrasound, Norway, in collaboraion wih NTNU

36 36 In he ER/ Ambulance In he Docor s Office Cardiac Monioring Foeal Monioring Rapid Decision suppor Tele-Medical Exper Consuling Applicaions In he Local Hospial Inernal Bleeding Cardiac Condiion Rapid, Accurae Diagnosis and Treamen Tele-Medical Exper Consuling Paien Visis Low Cos, Porable, Full Funcionaliy Wireless Tele-Medical Consuling Paien Screening Inermediae level Rapid, Accurae Diagnosis

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