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For the geometrically frustrated spinel system CdV2O4 with V3+ (S = 1) that undergoes structural and magnetic transitions at Tc1 = 97 K, and may exhibit a transition to the antiferromagnetic state at Tc2 = 35 K, the crystal structures at 299 and 85 K have been determined with space groups Fd3̄m and I41 /amd, respectively, by means of x-ray four-circle diffraction. At 85 K, the VO6 octahedron is distorted due to the Jahn–Teller effect with contraction of the V–O bond along the tetragonal c axis, and the network of V ions is achieved by the linkage of a distorted V4-tetrahedron block with two kinds of V–V bonds. On the basis of these structural properties, magnetic susceptibilities at temperatures between Tc1 and Tc2 are explained in terms of the tetragonally distorted pseudotetramer model.

This paper describes a method for the automated anatomical labeling of the bronchial branch extracted from a three-dimensional (3-D) chest X-ray CT image and its application to a virtual bronchoscopy system (VBS). Automated anatomical labeling is necessary for implementing an advanced computer-aided diagnosis system of 3-D medical images. This method performs the anatomical labeling of the bronchial branch using the knowledge base of the bronchial branch name. The knowledge base holds information on the bronchial branch as a set of rules for its anatomical labeling. A bronchus region is automatically extracted from a given 3-D CT image. A tree structure representing the essential structure of the extracted bronchus is recognized from the bronchus region. Anatomical labeling is performed by comparing this tree structure of the bronchus with the knowledge base. As an application, we implemented the function to automatically present the anatomical names of the branches that are shown in the currently rendered image in real time on the VBS. The result showed that the method could segment about 57% of the branches from CT images and extracted a tree structure of about 91% in branches in the segmented bronchus. The anatomical labeling method could assign the correct branch name to about 93% of the branches in the extracted tree structure. Anatomical names were appropriately displayed in the endoscopic view.

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