Biomedical Engineering Reference
In-Depth Information
Echoes from a Fixed View of Bovine Liver
#1
#2
RF Images from a Fixed View of Bovine Liver
50°C
corrected
50°C
25
37°C
50°C
20
0.5
0.5
0.5
1
1
1
15
1.5
1.5
1.5
2
2
2
10
2.5
2.5
2.5
5
3
3
3
3.5
3.5
3.5
0
37°C
2
4
6
246
246
0
5
10
15
20
Time (µs)
Lateral (mm)
FIGURE 13.1
Changes in backscattered ultrasound with temperature. (Left) Echoes measured from a single site in a 1 cm thick sample of fresh
bovine liver at temperatures from 37 to 50°C. The two delineated echoes (indicated by bands marked #1 and #2) shift with temperature and have
energies that appear to change with temperature (similar to Figure 13.4 in Arthur et al.
42
). (Right) RF images of a fixed region in bovine liver show-
ing apparent motion from 37 to 50°C. The right panel shows the image at 50°C after motion compensation (similar to Figure 13.3 in Arthur et al.
43
).
1D Te mperature image using
thermal strain
52
20
50
30
48
46
40
44
50
42
40
60
38
70
0
10
20
30
°C
Lateral (mm)
FIGURE 13.7
1D thermal strain temperature image from axial echo shifts in turkey breast muscle during nonuniform heating using the fix-
ture in Figure 13.5. Tissue was surrounded by water at 37°C. At time = 0 seconds 65°C water was pumped through the tissue center (black disk).
Compare to the 3D CBE image in Figure 13.14 from a different specimen of turkey. Thermocouple readings in planes adjacent to the image were
used to scale the strain image to give temperature estimates.
