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

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*

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

OBJECTIVE: The purpose of this study was to compare the precision of three-dimensional (3D) images acquired using iTero(R) (Align Technology Inc., San Jose, CA, USA) and Trios(R) (3Shape Dental Systems, Copenhagen, Denmark) digital intraoral scanners, and to evaluate the effects of the severity of tooth irregularities and scanning sequence on precision. METHODS: Dental arch models were fabricated with differing degrees of tooth irregularity and divided into 2 groups based on scanning sequence. To assess their precision, images were superimposed and an optimized superimposition algorithm was employed to measure any 3D deviation. The t-test, paired t-test, and one-way ANOVA were performed (p < 0.05) for statistical analysis. RESULTS: The iTero(R) and Trios(R) systems showed no statistically significant difference in precision among models with differing degrees of tooth irregularity. However, there were statistically significant differences in the precision of the 2 scanners when the starting points of scanning were different. The iTero(R) scanner (mean deviation, 29.84 +/- 12.08 microm) proved to be less precise than the Trios(R) scanner (22.17 +/- 4.47 microm). CONCLUSIONS: The precision of 3D images differed according to the degree of tooth irregularity, scanning sequence, and scanner type. However, from a clinical standpoint, both scanners were highly accurate regardless of the degree of tooth irregularity.
Dental Arch ; Imaging, Three-Dimensional* ; Tooth*

No abstract available.
Imaging, Three-Dimensional ; Magnetic Resonance Angiography*

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

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

OBJECTIVE: Cadaver's sectioned images with high resolution and real color could be used as the source of realistic three-dimensional images. If the sectioned images are registered to a patient's MRIs, three-dimensional images with high resolution and real color that fit the patient, can be produced; the three-dimensional images enable realistic virtual surgery for the patient. The objective of this study was to verify the registration of a cadaver's sectioned images to a patient's head MRIs. METHODS: The sectioned images of the heads of cadaver were associated with segmented images selected at 3 mm intervals. The patient had his head MR scanned at 3 mm intervals; the MRIs were segmented. Software to register the cadaver's sectioned images to the patient's MRIs was developed. On this software, the corresponding dots were identified on both the sectioned images and the MRIs either manually or automatically using segmented images. RESULTS: The registered sectioned images corresponded to the patient's MRIs. Both manual and automatic registrations were satisfied. CONCLUSION: Further study is needed for registering sectioned images to actual patients.
Cadaver ; Head ; Humans ; Imaging, Three-Dimensional