a mass conservation based optical flow method for cardiac motion correction in 3d pet data m dawood...
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A Mass Conservation Based Optical Flow Method for Cardiac Motion Correction in 3D PET Data
M Dawood1,2, C Brune2, F Büther1, KP Schäfers1
European Institute for Molecular Imaging Department of Computer Science,
University of Münster, Germany
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Motion Correction on 3D PET/CT Data with Optical Flow Algorithms
Cardiac Motion and Partial Volume
Coronal slice through non-attenuated PET1 h. p. i., 18FDG, CHD patient
Cardiac motion
Ungated dataLarge blur, low noise(Problem in plaque imaging)
One phaseSmall blur, high noise
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Motion Correction on 3D PET/CT Data with Optical Flow Algorithms
…
Step 1: Gating
ECG signal
Series of images reconstructed from cardiac gated PET acquisition
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Motion Correction on 3D PET/CT Data with Optical Flow Algorithms
Mass conservation in cardiac data
Systole Diastole
Mass Conservation
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Motion Correction on 3D PET/CT Data with Optical Flow Algorithms
Step 2: Motion Estimation
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Motion Correction on 3D PET/CT Data with Optical Flow Algorithms
All gates deformed to Diastole
Visual result
Cardiac phases
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Motion Correction on 3D PET/CT Data with Optical Flow Algorithms
Ungated dataLarge blur, low noise Noise 25
One phaseSmall blur, high noise Noise 36
All phases motion correctedSmall blur, low noise Noise 22
Visual result
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Motion Correction on 3D PET/CT Data with Optical Flow Algorithms
Quantitative results on patient data
Data:
14 patients with known CHDca. 4 MBq/Kg body weight 18F-FDGScan time ca. 15 minutes, 1:15 hours post injectionListmode acquisition on Siemens Biograph 16 scanner
Quatification methods:
Correlation of ROI (40x40x40) with target phaseMyocardial thickness. FWHM of Gaussian fit to line profileMean activity in blood pool in LV
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Motion Correction on 3D PET/CT Data with Optical Flow Algorithms
Quantitative results 1: Correlation of end-systolic gate with target phase
1 2 3 4 5 6 7 8 9 10 11 12 13 140.700000000000001
0.750000000000001
0.800000000000001
0.850000000000001
0.900000000000001
0.950000000000001
1
BeforeAfter
Patient No
Corr
elati
on c
oeffi
cien
t
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Motion Correction on 3D PET/CT Data with Optical Flow Algorithms
Quantitative results 2: Myocardial thickness
1 2 3 4 5 6 7 8 9 10 11 12 13 14 Avg3
3.5
4
4.5
5
5.5
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Patient Number
Myo
card
ial t
hick
ness
[mm
]
End-systoleEnd-diastoleEnd-systole after MC
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Motion Correction on 3D PET/CT Data with Optical Flow Algorithms
Quantitative results 3: Mean activity in blood pool
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Motion Correction on 3D PET/CT Data with Optical Flow Algorithms
Thank you
To conclude:
A method for cardiac motion and partial volume correction was presented.
The results on patient data show that the motion was corrected precisely.