Strain Variation for B-Mode Image

Presentation on theme: "Strain Variation for B-Mode Image"— Presentation transcript:

1 Strain Variation for B-Mode Image
葉文俊 呂仁碩 李承諺

2 Previous Work - Block Size - Multi-Level Speckle Tracking Correction
Improve Speckle Tracking Correction - Block Size - Multi-Level Speckle Tracking Correction Improve Elastic Image Resolution - Strain - Shorten、Elongation - Direction

3 Displacement and Strain
Our approach x1 x1+d x d1 Origin： After Strain d2

4 Result Thyroid Image Strain Image Image Size：450 X 450 pixels
Block Size：50 X 50 pixels Thyroid Image Strain Image 2 4 6 8 10 12 14 16 18 20 22

5 Trade-Off If strain variation between images is increased, speckle correlation is decreased and speckle tracking correction is decreased. If strain variation between images is decreased, speckle correlation is increased and speckle tracking correction is increased.

6 Method nst13 (new speckle tracking between 1st and 3rd images) = st12+st23 ost13 (original speckle tracking between 1st and 3rd images) = st13 1st 2nd 3rd

7 Result Summation of strain with the 1% strain variation between 2 images. 1-2 1-3= 1-4= 1-5= 1-6= 1-7=

8 Result Summation of strain with the 2% strain variation between 2 images. 1-3 1-5= 1-7= Summation of strain with the 3% strain variation between 2 images. 1-4 1-7=

9 Result Summation of strain with the 1%
strain variation between 2 images. Summation of strain with the 2% strain variation between 2 images. 1-7= 1-7= Summation of strain with the 3% strain variation between 2 images. No summation of strain with the 6% strain variation between 2 images. 1-7= 1-7

10 Result (Breast Phantom)
Shorten 1-2 1-3 1-4 Elongation 1-2 1-3 1-4

11 Result (Breast Phantom)
X Direction 1-2 1-3 1-4

12 FFT-based Speckle Analysis
為了解決Speckle tracking所遭遇的問題 : Block size v.s. Resolution Motion 量化誤差 v.s. 內插 Speckle移動距離 v.s. Speckle變形

13 FFT-based Speckle Analysis
由頻域對B-mode影像進行分析 Z軸方向的一段組織反射信號 z

14 FFT-based Speckle Analysis
信號與系統理論 ： a(z)  A(ω) a(kz)  A(ω/k) f

15 FFT-based Speckle Analysis
將此方法推廣至二維 ： 探頭 fz x fx z

16 FFT-based Speckle Analysis
使用一系列以photoshop進行縮放調整之speckle影像進行模擬

17 FFT-based Speckle Analysis
將每張影像取出31 X 31 pixels部分進行分析 31 X 31 100 pixels 100 pixels

18 FFT-based Speckle Analysis
取hann window，進行128點二維富利葉轉換後，只保留正頻率之magnitude部分資訊。 將所得之頻域資訊，經過帶通、投影。

19 FFT-based Speckle Analysis
用來分析相鄰frame之間，是否有頻率shift fz fx 投影 帶通

20 FFT-based Speckle Analysis
3000 100 2500 200 2000 300 1500 400 1000 500 500 600 1 2 3 4 5 6 7 8 9 10 11

21 FFT-based Speckle Analysis
2500 100 2000 200 300 1500 400 1000 500 500 600 1 2 3 4 5 6 7 8 9 10 11

22 FFT-based Speckle Analysis
現階段模擬結果，印證最初之原理假設。 尚未考慮散射子重新分佈、雜訊。 需進一步設計定量分析的方法。 可配合既有之speckle tracking技術。