The Comparison of Modified Demons Algorithm and FFD Algorithm Based On B-Spline and Analysis of Morphology of Normal Liver and Tumor by Breathing Motion
G Gong1*, H wang2, Y Yin3, (1) ,,,(2) shandong cancer hospital, Jinan, ,(3) ,Jinan,SU-E-J-133 Sunday 3:00PM - 6:00PM Room: Exhibit Hall
Purpose: Through comparing the modified demons algorithm and FFD algorithm based on B-spline, and combing four-dimensional computed tomography (4D-CT), we discussed the morphology of normal liver and tumor by breathing motion of hepatocellular carcinoma patients.
Methods:8 hepatocellular carcinoma (HCC) patients accepted radiotherapy and TACE was selected, the simulate positioning was in four-dimensional computed tomography (4D-CT) pattern and 4D-CT images were segmented into 10-series CT images which were named CT0, CT10 to CT80, CT90 according to the respiratory phases. We used the modified demons algorithm and FFD algorithm based on B-spline respectively to deform the images, and the end-exhale image CT50 was the reference image. The normalized mutual information (NMI), hausdorff distance (NMI) and time consuming were used to verify the performance of the registration methods.
Results:The average NMI for the end-inhale and end-exhale images of 8 HCC patients after demons registration method in mode 1 improved 1.76% comparing with that in mode 2 and 4.75% improving than FFD algorithm. And the difference of after demons method reduced 15.2% comparing with FFD model algorithm. In addition, demons algorithm has the absolute advantage in time consuming.
Conclusion: The breathing movement for deformation of normal liver and tumor targets is significant, and the modified demons registration method can deform 4D-CT images effectively.