Transcript EXTRACTING ARTERIAL BLOOD CURVE FROM PET IMAGE

Turku PET Centre
EXTRACTING ARTERIAL BLOOD
CURVE FROM PET IMAGE - UPDATE
Abdominal aorta in [15O]H2O studies
Turku PET Centre
Improved method
• Method contains
– 95% thresholding
– Recovery coefficient
• User has to specify the range of planes
• Initial value for diameter is not needed
21.7.2015
Turku PET Centre
Thresholding
• For each frame
– Find the pixel with maximum activity (inside the vessel)
– Include all pixels where activity value is greater than
0.95*maximum activity (=thresholding)
– Calculate mean
=> thresholded TAC
21.7.2015
Turku PET Centre
Recovery coefficient
• Estimate diameter of the vessel
• Calculate the recovery coefficient

RC  1  e
21.7.2015
R2
 FWHM 
2*

2.355


Turku PET Centre
2
Resulting input TAC
RC * thresholded TAC
21.7.2015
Turku PET Centre
Diameter estimates (mm)
subject
plane
3
4
5
6
7
8
9
10
11
12
13
14
15
mean
median
sd
21.7.2015
04064
04066
04079
04085
04104
15.1
16.3
16.6
16.8
16.7
13.0
15.2
15.2
13.9
14.0
15.5
15.1
13.2
15.6
18.2
14.1
13.8
14.3
14.9
13.7
17.2
14.6
15.5
15.9
15.0
15.60753 15.10586 14.71063 14.94992 15.63047
15.33046 15.06145 14.34608 15.26634 14.98045
1.121504 1.106532 1.388988 1.263116 2.308937
Turku PET Centre
04106
04122
04132
14.8
14.1
18.7
13.2
17.9
16.3
16.9
16.7
16.4
16.8
11.7
15.4
17.6
14.4
18.2
14.0
14.8
16.4
12.1
16.4
16.4
15.42950 15.57845 16.99924
16.29435 15.44876 16.44909
2.247811 1.031579 1.00873
Result TACs
21.7.2015
Turku PET Centre
AUC (image inputTAC)
AUC correlations
45000
40000
35000
30000
25000
20000
15000
10000
5000
0
0
10000
20000
30000
40000
AUC (blood pump TAC)
21.7.2015
Turku PET Centre
50000
Future plans
• Article dealing with input extraction
• Validation of diameter estimates with help of
ultrasound results
• Comparisons with ICA
21.7.2015
Turku PET Centre