Hongjian Shi

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INTRODUCTION The visualization of cervical vertebral morphology has potential in skeletal age assessment; however, thus far, it has only been described in planar images. The objective of this article is to present a novel segmentation algorithm for automatic 3-dimensional (3D) reconstruction of individual cervical vertebrae from cone-beam(More)
Objective To segment and measure the upper airway using cone-beam computed tomography (CBCT). This information may be useful as an imaging biomarker in the diagnostic assessment of patients with obstructive sleep apnea and in the planning of any necessary therapy. Methods With Institutional Review Board Approval, anonymous CBCT datasets from subjects who(More)
A novel shape based segmentation approach is proposed by modifying the external energy component of a deformable model. The proposed external energy component depends not only on the gray level of the images but also on the shape information which is obtained from the signed distance maps of objects in a given data set. The gray level distribution and the(More)
Purpose Segmentation of the maxillary sinuses for three-dimensional (3D) reconstruction, visualization and volumetry is sought using an automated algorithm applied to cone beam computed tomographic (CBCT) data sets. Materials and Methods Cone beam computed tomography (CBCT) data sets of three subjects aged 9, 17, and 27 were used in 3D segmentation and(More)
In fringe projection, the CCD camera and the projector are often placed at equal height. In this paper, we will study the calibration of an unequal arrangement of the CCD camera and the projector. The principle of fringe projection with two-dimensional digital image correlation to acquire the profile of object surface is described in detail. By formula(More)
In this work, we aim at validating some soft tissue deformation models using high-resolution micro-computed tomography (Micro-CT) images. The imaging technique plays a key role in detecting the tissue deformation details in the contact region between the tissue and the surgical tool (probe) for small force loads and provides good capabilities of creating(More)
A mathematical description of the absolute surface height distribution in generalized fringe projection profilometry under large measuring depth range is presented. Based on least-squares polynomial fitting, a nonlinear calibration to determine the mapping between phase change and surface height is proposed by considering the unequal height arrangement of(More)
Measuring deformation of vibrating specimens whose dimensions are in the submillimeter range introduces a number of difficulties using laser interferometry. Normal interferometry is not suitable because of a phase ambiguity problem. In addition, the noise effect is much more serious in the measurement of small objects because a high-magnification lens is(More)