問題一覧
1
2 dimensional
pixel
2
Pixel size formula
fov/matrix size
3
Voxel formula
pixel size×slice thickness
4
The tissue volume
voxel
5
Refers to the numeric information contained in each pixel
ct number/hounsfield unit
6
The diameter of image reconstruction
fov
7
FOV is increased, fixed matrix size
increase/larger pixel size
8
Fixed FOV, increased matrix size
decrease/smaller pixel size
9
Compute the pixel size for the following characteristics of CT imagers FOV of 20 cm, 128 x 128 matrix FOV of 20 cm, 512 x 512 matrix FOV 36 cm, 512 x 512 matrix
1.56/1.6, 0.39/0.4, 0.7
10
If each of the three scans in the preceding questions was conducted at 5-mm slice thickness, what would be the respective voxel sizes?
12.8 mm³, 0.8 mm³, 2.45 mm³
11
Used to assess the nature of the tissue
ct number/hounsfield unit
12
scale of CT number
HU
13
Ct number range
-1000 to +3000
14
LAC of bone
0.528
15
LAC of muscle
0.237
16
LAC of brain white
0.213
17
LAC of brain grey
0.212
18
LAC of blood
0.208
19
LAC of water
0.206
20
LAC of fat
0.185
21
LAC of lung
0.093
22
LAC of air
0.0004
23
Hounsfield unit formula
μt-μw/μw×k
24
HU of air
-1000
25
HU of lungs
-250 to -850
26
HU of fat
-100
27
HU of orbit
-25
28
HU of water
0
29
HU of cyst
-5 to +10
30
HU of fluid
0 to +25
31
HU of tumor
+20 to +100
32
HU of blood (fluid)
+20 to +50
33
HU of blood (clothed)
+50 to +75
34
HU of blood (old)
+10 to +15
35
HU of brain
+20 to +40
36
HU of muscle
+35 to +50
37
HU of gallbladder
+5 to +30
38
HU of liver
+40 to +70
39
HU of aorta
+35 to +50
40
HU of bone
+150 to +1000
41
HU of metal
+2000 to +4000