ABSTRACT
Phased array coils (multiple receiver coil systems) have been extensively used for acquisition of MR images owing to their ability of increasing SNR, extending field-of-view (FOV), and reducing acquisition time. But the SOS algorithm,which is main method for phased array image reconstruction,will cause inhomogeneity in reconstructed image. A regularized least square method for phased array image combination is proposed in this paper. In the method, an additional reference scan is performed in advance. By using the reference scan, coil sensitivity map can be acquired, and image reconstructed from reference scan can be used as reference data in the regulation term. Experiments showed that the image uniformity was greatly improved by this method with scanning phantom and volunteer.
Subject(s)
Humans , Algorithms , Image Enhancement , Methods , Image Processing, Computer-Assisted , Methods , Magnetic Resonance Imaging , MethodsABSTRACT
Objective To establish a new automatic lung segmentation method in order to deal with the omission of pleural nodules and pulmonary vessels. Methods Lung parenchyma were extracted from chest CT images with the inversed operation of 2D region growing and connected area classification, then the contours and locating the contour points were traced with scan line searching. Finally, the parameters of lung contour points were analyzed to locate the contours distorted by nodules, and curve spline was used to correct distorted contours. Results The experimental results of many sets of CT images verified that the technique proposed was effective. The comparison with other contour correction algorithm verified that line searching contour correction was superior. Conclusion The proposed algorithm includes tumors in the segment results, and confirms the integrality, veracity, real-time quality of this auto-segmentation method.