Image Optimisation. -How to Get the Most out of your Echo Machine. Katarina Winkler, Biomedicinsk analytiker, Barnhjärtcentrum i Lund

Transcription

1 Image Optimisation -How to Get the Most out of your Echo Machine analytiker, Barnhjärtcentrum i Lund

2

3 Image Optimisation Helpful tips to improve the 2D-Image and Doppler registrations. Common adjustments for the most routinely used applications on the ultrasound machine. Frequently made beginner mistakes. I will not go deep into physics

4 Image Optimisation What is good quality image?

5 Applications on the Ultrasound Machine 2D-Imaging M-mode Spectral Doppler Color Doppler Tissue Doppler 3D-Imaging

6 Presets Create presets. Do not use factory presets. All machines at the lab MUST have the same presets. Enables uniformed exams.

7 2D Optimisation GAIN iscan ZOOM Depth Focus

8 Higher frequency 2D Optimisation Selection of Transducer Better resolution - Less penetration Lower frequency Better penetration - Less resolution Broad band transducers have a range of frequencies.

9 2D Optimisation Adjust the sector size to increase Framerate Depth Set the depth to a minimum according to what need to be imaged. Sector width Set the width as narrow as possible. Lateral resolution

10 2D Optimisation Sector size Excessive depth Depth: 18 cm Wide sector angle Fame Rate: 45 Hz Adjusted sector size Depth:12 cm Decreased sector angle Frame Rate: 76 Hz

11 Overall Gain 2D Optimization Gain settings Adjusts the Brightness in the Image Equal in the whole image Influences Receiving Signals

12 2D Optimization Gain settings TGC Time-Gain Compensation Adjusts Gain at a Specific Depth Compensate for the Attenuation of Ultrasound

13 2D Optimisation Gain settings

14 2D Optimisation Gain settings iscan/auto Optimisation The machine analyses the tissue and automatically adjusts the gain settings Good starting point

15 2D Optimisation Gain settings Over gained settings Correct gain settings

16 2D Optimisation Focus Works as a photo camera lens Lateral Resolution Multiple focus zones Decreases Frame Rate!

17 2D Optimisation

18 2D Optimisation Zoom Small region of interest High Frame rate High resolution

19 2D Optimisation Frame Rate 87 Hz Frame Rate 120 Hz

20 2D Optimisation 2 nd Harmonic Imaging Reduces Image Artefacts by Filtering out Harmonic signals. Send at a lower frequency and listen for a higher frequency. Higher overtone less noise but also less energy.

21 2D Optimisation Fundamental 2nd Harmonic

22 2D Optimisation Create a 2D image with highest detail Use the highest frequency transducer without compromising penetration Use minimal depth setting Use small sector width Optimise gain settings Use zoom function for small area of interest Use the focal zone

23 M-mode Plots movements of structures along the cursor and are displayed along a time axis. Track fast movements Very High Resolution

24 M-mode Wrong positioning LVID: 60 mm Accurate positioning LVID: 49 mm

25 Ultrasound Doppler F = 2F 0V C cos θ Angle between the blood flow and the ultrasound beam is very important Stay as parallel to flow as possible Never exceed 20 degrees

26 Ultrasound Doppler

27 Ultrasound Doppler Spectral Doppler The scale is set to high Correct setting

28 Ultrasound Doppler Spectral Doppler Slow sweep speed 50 mm/s Fast sweep speed 150 mm/s

29 Ultrasound Doppler Spectral Doppler Over gained settings Correct gain settings

30 Ultrasound Doppler Spectral Doppler Spectral Doppler signals for accurate measurements. Doppler angle <20º Adjust the Scale Adjust Sweep speed Optimise Gain settings

31 Ultrasound Doppler Color doppler 2D-gain set too high Correct settings

32 Ultrasound Doppler Color doppler Color Doppler Gain

33 Ultrasound Doppler Color doppler Color Box Size

34 Ultrasound Doppler Color doppler Color Doppler Scale: 66 cm/s Color Doppler Scale: 53 cm/s

35 Ultrasound Doppler Color doppler Color Doppler Scale: 67 cm/s Color Doppler Scale: 123 cm/s

36 Ultrasound Doppler Color doppler Well defined Color Doppler jets with high Frame Rates Decrease 2D gain Adjust Color Doppler Gain Minimize Color Box Adjust Color Doppler Scale

37 What is good a quality image? 2D image with highest detail information Spectral doppler for accurate measurements Color doppler with high frame rates and well defined jets

38 Thank you!