ABSTRACT
The aim of this study was to propose an algorithm for three-dimensional projection onto convex sets (3D POCS) to achieve super resolution reconstruction of 3D lung computer tomography (CT) images, and to introduce multi-resolution mixed display mode to make 3D visualization of pulmonary nodules. Firstly, we built the low resolution 3D images which have spatial displacement in sub pixel level between each other and generate the reference image. Then, we mapped the low resolution images into the high resolution reference image using 3D motion estimation and revised the reference image based on the consistency constraint convex sets to reconstruct the 3D high resolution images iteratively. Finally, we displayed the different resolution images simultaneously. We then estimated the performance of provided method on 5 image sets and compared them with those of 3 interpolation reconstruction methods. The experiments showed that the performance of 3D POCS algorithm was better than that of 3 interpolation reconstruction methods in two aspects, i.e., subjective and objective aspects, and mixed display mode is suitable to the 3D visualization of high resolution of pulmonary nodules.
Subject(s)
Humans , Algorithms , Imaging, Three-Dimensional , Lung , Pathology , Multiple Pulmonary Nodules , Diagnosis , Tomography, X-Ray ComputedABSTRACT
In this paper, we describe a study on visualization of SW atlases. Firstly, data structures in axial, coronal and sagittal directions are generated by SW atlases' raw data after pre-processing. Secondly, we produce 3D SW atlases through setting gray intensity and spaces between slices. Thirdly, we integrate the atlas into the neurosurgery navigation system and realize the visualization of SW atlases. Finally, we realize brain anatomy structures labeling and real-time display in neurosurgery navigation system.
Subject(s)
Humans , Anatomy, Artistic , Brain Mapping , Neuronavigation , Methods , Neurosurgery , MethodsABSTRACT
Objective: To evaluate the surgView-RFT electromagnetic navigation system in radiofrequency thermocoagulation(RFT). Methods: 6 foramen ovales of 3 cadavers were punctured by 3 beginners. Every one tried 5 times by free-hand and 5 times by SurgView-RFT electromagnetic navigation-guidance. After each puncture, CT scans were used as golden standard to measure the distance between the tip of needle and the anterior margin of the foramen ovale. T test and variance of SAS 6.12 statistical software was used to do the statistic analysis. Results: The punctures by free-hand failed, and the distances between the tip of needle and the anterior margin of the foramen ovale were 8-10.6 mm. The punctures by navigation guidance were successful, and the distances between the tip of needle and the anterior margin of the foramen ovale were 2.68-3.54 mm. The error of navigation system was 0.59 mm which was verified by CT scan. There was significant difference between free-hand puncture and navigation-guided puncture. Conclusion: The surgView-RFT electromagnetic navigation system is characteristic with high performance, high accuracy and minimal invasion, while it is applied in training or clinical using.
ABSTRACT
3D medical image segmentation is a fundamental technique for computer assisted surgery and therapy. There exist various segmentation algorithms, but still we hope to have a more efficient and intuitive evaluation method for validation. In this paper, after reviewing the existing validation methods, we propose a new approach for 3D image segmentation validation. The details of the method are introduced in two parts: local error validation and global accuracy validation. Then, we apply it to validate three typical segmentation algorithms and a user proposed hybrid segmentation method in our experiment. The hybrid approach is also briefly introduced. The experimental results reveal that the proposed validation method can evaluate the employed segmentation methods more accurately and intuitionally.