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Abstract Objective To evaluate the accuracy of three-dimensional (3D) Cone Beam Computed Tomography (CBCT) and Computed Tomography (CT) reconstructions of human temporal bones compared with in situ measurements. Material and methods Experimental anatomical study of 10 human temporal bones. Wilcoxon's test was used to compare 8 distances on each temporal bone measured in situ and then on 3D CT and CBCT reconstructions. Six landmarks were used: external auditory canal (EAC), tip of the mastoid process, tip of the occiput, zygoma, a point situated 1 cm above the tip of the mastoid process (T0) (open technique: lower limit of the mastoidectomy), head of stapes. Results No significant difference was observed between the 3 measuring techniques for any of the distances studied (P > 0.05). Discussion This study demonstrates the equivalence of CBCT and CT for temporal bone measurements. Conclusion CBCT is a new imaging modality providing 3D reconstructions of the temporal bone that are as reliable as those obtained by CT. As a result of better spatial resolution compared to CT, CBCT is associated with a significantly lower radiation dose. This technique constitutes a morphological progress, as CBCT is comparable to CT, allowing investigation of pathological ears with a lower radiation dose. [ABSTRACT FROM AUTHOR]

In this paper, a novel depth extraction method based on the regional feature point is proposed to enhance the estimation accuracy of the depth and is used to reconstruct 3D scene. Specifically, each elemental image is segmented into many regions firstly and the depth of the object point corresponding to each feature point in each region is extracted, then the depth corresponding to all feature points can be calculated to express the depth corresponding to all object points, which can enhance the accuracy by solving the wrong matching problem in weak texture regions and reduce the amount of calculation. To segment each elemental image properly, we first preprocess each elemental image and segment each elemental image into many regions, then merge some similar regions. Some computational reconstruction experiments are carried to verify the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Summary: The function of lymph nodes is greatly influenced by their unique microanatomy, in which distinct subpopulations of cells are compartmentalized by a meshwork of reticular cells and fibres, specialized blood and lymphatic vessels and nerves. Using antibodies against extracellular matrix (ECM) proteins (fibronectin, collagen IV and laminin), proteoglycan (perlecan), and a fibroblastic marker (ERTR-7), the distribution and molecular organization of the system of reticular fibres was investigated by three-dimensional (3D) reconstruction methods. Fibronectin, collagen IV and laminin are restricted to reticular fibres and have a similar distribution pattern, whereas perlecan is limited to the vascular system of the lymph node. Various compartments of the lymph node, such as the B-cell follicle, paracortex (including the high endothelial venules and paracortical cord), and medulla have been reconstructed to visualize their vasculature with respect to B and T cells. Since the morphology of lymph nodes may change significantly in pathological conditions, different compartments of reactive lymph node (after low-dose Listeria monocytogenes infection), especially germinal centres, were also investigated. The data presented here should facilitate our understanding of the 3D organization of non-immune cell components of lymph nodes, which is crucial for cell adhesion, migration, activation, and differentiation in normal and pathological conditions. [Copyright &y& Elsevier]