A Compton camera, which is based on the geometrical interpretation of Compton scattering, is a very promising gamma-ray imaging device considering its several advantages over the conventional gamma-ray imaging devices: high imaging sensitivity, 3-D imaging capability from a fixed position, multi-tracing functionality, and almost no limitation in photon energy. In the present study, a Monte Carlo-based, user-friendly Compton imaging simulator was developed in the form of a graphical user interface (GUI) based on Geant4 and MATLAB (TM). The simulator was tested against the experimental result of the double-scattering Compton camera, which is under development at Hanyang University in Korea. The imaging resolution of the simulated Compton image well agreed with that of the measured image. The imaging sensitivity of the measured data was 2~3 times higher than that of the simulated data, which is due to the fact that the measured data contains the random coincidence events. The performance of a stacking-structure type Compton camera was evaluated by using the simulator. The result shows that the Compton camera shows its highest performance when it uses 4 layers of scatterer detectors.
Imaging, Three-Dimensional ; Korea

No abstract available.
Erythrocytes ; Imaging, Three-Dimensional ; Microscopy

PURPOSE: To investigate the role of 3D imaging in the sinonasal mass. MATERIALS AND METHODS: Twenty patients with sinonasal mass(squamous cell carcinoma[n=6], spindle cell carcinoma[n=1}, angiomatous polyp[n=1}, giant cell reparative granuloma[n=1}, non-Hodgkin's lymphoma[n=1}, melanoma[n=1}, angiofibroma[n=1}, pyocele[n=1}, inverted papilloma[n=1}) were studied with spiral CT. Reconstruction of surface rendered 3D images and segmentations were performed and compared with the 2D image. RESULTS: The 3D images enabled easy understanding of the characteristics of the mass in 12 casese. The 3D images displayed pathway of tumor extension in 5 cases and werehelpful in assessing the primary site of the mass in 3 cases. In two cases with encasement of ICA by the mass, assesment of relationship between the mass and vessels were possible through the segmentation. CONCLUSION: The 3D image, as an adjunct to the 2D image, can help to evaluate the virtual appearance of bony change, the degree of extension of mass, the spreading route, the evaluation of origin site. It also provides valuable 3-dimensional conception of the mass, especially for the surgeon.
Imaging, Three-Dimensional* ; Tomography, Spiral Computed

Tissue clearing technology is currently one of the fastest growing fields in biomedical sciences. Tissue clearing techniques have become a powerful approach to understand further the structural information of intact biological tissues. Moreover, technological improvements in tissue clearing and optics allowed the visualization of neural network in the whole brain tissue with subcellular resolution. Here, we described an overview of various tissue-clearing techniques, with focus on the tissue-hydrogel mediated clearing methods, and discussed the main advantages and limitations of transparent tissue for clinical diagnosis.
Brain ; Diagnosis ; Imaging, Three-Dimensional ; Neurosciences

No abstract available.
Ductus Arteriosus, Patent* ; Imaging, Three-Dimensional*

OBJECTIVE: Watershed algorithm is image segmentation algorithm divides the image into numerous small regions. This paper proposes a new approach to extract the lung region from the three dimensional color image of Frozen Human Body (Visible Human Male) based on watershed algorithm. METHODS: After applying this algorithm to input image and getting the small regions, we merge these small regions into one region with three measures based on color, edge marker, and SURFACE respectively. RESULTS: We can say that the smaller number of FALSE-POSITIVE and TRUE NEGATIVE voxels and the larger number of FALSE POSITIVE voxels are better result. Graph shows change in the number of voxel in above groups of the left lung detection when tau color change with tau em is 0.7. We think that the result at the range of tau color from 110 to 180 are better than the other results in Graph. CONCLUSION: Comparing with our previous work, we newly use Canny edge filter for edge marker and define SURFACE-based dissimilarity to relax the problem of its step. The users must select a point within the lung region and some thresholds (taucolor, tauem, tauhigh, taulow, delta) to detect the target region.
Human Body ; Humans* ; Imaging, Three-Dimensional ; Lung*

It is possible to compare three-dimensional image of patterned injury in virtual space with object using 3D/CAD supported photogrammetry(FPHG). this method make it possible to examine patterned injuries of skin, soft tissue and bone for matching instruments in shape, size and angle without altering. Generally, 3D measuring of objects require 3D digitizer or series of photographs taking by metric camera. We developed program which calibrate pictures taken by non-calibrated commercial camera and un distorted image. This image and objet model n can be examined with respect to matching shapes using 3D/CAD system.
Imaging, Three-Dimensional ; Photogrammetry ; Skin ; United Nations

Small bowel obstruction is a relatively common clinical condition and its diagnosis is based on the clinical signs, the patient's history and the radiologic findings. For a patient with suspected small bowel obstruction, it is essential to determine the site, location and cause of obstruction for the appropriate management. Because of the poor accuracy of plain radiography, computed tomography (CT) now has an essential role to diagnose bowel obstruction. With the recent evolution of conventional CT into multi-detector computed tomography (MDCT), it is possible to obtain cross sectional images with high spatial resolution and different post-processes can be done, such as obtaining the volume rendering (VR), maximum intensity projection (MIP), or multiplanar reformatted (MPR) images from the volume data. In this article, we illustrate and discuss the utility of the multiplanar images of MDCT for diagnosing the sites, causes and complications of small bowel obstruction.
Humans ; Imaging, Three-Dimensional ; Multidetector Computed Tomography

OBJECTIVEThis work lays the foundation for establishing a digital model database with normal occlusion. A digital dental cast is acquired through grating projection, and model features are measured through reverse engineering.

METHODSThe grating projection system controlled by a computer was projected onto the surface of a normal dental model. Three-dimensional contour data were obtained through multi-angle shooting. A three-dimensional model was constructed, and the model features were analyzed by using reverse engineering. The digital model was compared with the plaster model to determine the accuracy of the measurement system.

RESULTSThe structure of three-dimensional reconstruction model was clear. The digital models of two measurements exhibited no significant difference (P > 0.05). When digital and plaster models were measured, we found that the crown length and arch width were not statistically different (P > 0.05), whereas the difference between the crown width and arch length was statistically significant (P < 0.05).

CONCLUSIONThe reconstruction of a digital model by using the grating projection technique and reverse engineering can be used for dental model measurement in clinic al and scientific research and can provide a scientific method for establishing a digital model database with normal occlusion.

OBJECTIVETo evaluate the clinical application effect of a three-dimensional craniomaxillofacial measurement instrument.

METHODSA three-dimensional craniomaxillofacial measurement instrument was developed. Twelve patients of unilateral fracture of zygoma complex were treated with the help of the three-dimensional craniomaxillofacial measurement instrument.

RESULTSThe therapeutic effects of twelve patients were satisfactory with the three-dimensional craniomaxillofacial measurement instrument. No complication occurred, such as infection, injury of nerves and veins.

CONCLUSIONThree-dimensional craniomaxillofacial measurement instrument can exactly measure craniomaxillofacial hard tissue, and has adjuvant effect to restore and fix the fracture of unilateral zygoma complex.