OBJECTIVE: Unfolding is a rendering method to visualize organs at a glance by virtually incising them. Although conventional methods exploit gray-scale volume datasets such as CT or MR images, we use the Visible Korean Human dataset preserving actual color. This can be helpful for the study of anatomical knowledge. Segmented images of Visible Korean Human dataset store the boundary of organs. Since medical experts manually perform the segmentation from anatomical color images, it is very time-consuming. In general, therefore, some images selectively sampled with interval from entire color images are segmented. When we generate a segment volume dataset with the selected images, final results are deteriorated due to lack of segmentation information for missed images. In this paper, we solve this problem by generating intermediate images without performing a manual segmentation. METHODS: Firstly, after comparing differences of organ's contours in between two consecutive segmented images, we represent the differences as a user-defined value in the intermediate images. This procedure is repeated for all pairs of manually segmented images to reconstruct entire volume data consist of manually segmented images and their intermediate images. In rendering stage, we perform the radial volume ray casting along with the central path of target organ. If a ray reaches to a region having the user-defined values, we advance over the region without compositions to the boundary of that region. Then the color composition is begun by performing backtracking, since the advanced region is regarded to the thickness of it. RESULTS: As a result, we can produce high quality unfolding images for the stomach, colon, bronchus, and artery of the Visible Korea Human dataset. CONCLUSION: Since our approach can be applied to virtual dissection including actual human colors, it is helpful for the endoscopy and anatomy studies.
Arteries ; Bronchi ; Colon ; Endoscopy ; Humans ; Korea ; Stomach

OBJECTIVE: After drawing and stacking contour of structures, which are identifed in the serially sectioned images, three-dimensional (3D) images can be made by surface reconstruction. The 3D images can be selected and rotated in a real time. The purpose of this research is to compose software of automatic surface reconstruction for making 3D images. METHODS: Contours of 55 structures in the 613 magnetic resonance images of whole body were drawn to make segmented images. We composed automatic software for stacking contours of a structure, for converting the contours into polygons, and for connecting vertices of the neighboring polygons to fill gaps between polygons with triangular surfaces. The surface reconstruction software was excuted to make 3D images of 55 structures. RESULTS: Virtual dissection software, on which 3D images could be selected and rotated, was composed. CONCLUSION: For other research, this like program can be composed for automatic surface reconstruction; several kinds of commercial software can be used for manual or automatic surface reconstruction. Investigators might choose one of the methods in consideration of their only circumstances.
Humans ; Imaging, Three-Dimensional ; Research Personnel

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

No abstract available.
Kidney*

BACKGROUND: The curved sectional planes of the human body can provide a new approach of surface anatomy that the classical horizontal, coronal, and sagittal planes cannot do. The purpose of this study was to verify whether the curved sectional planes contribute to the morphological comprehension of anatomical structures. METHODS: By stacking the sectioned images of a male cadaver, a volume model of the right half body was produced (voxel size 1 mm). The sectioned images with the segmentation data were also used to build another volume model. The volume models were peeled and rotated to be screen captured. The captured images were loaded on user-friendly browsing software that had been made in the laboratory. RESULTS: The browsing software was downloadable from the authors' homepage (anatomy.co.kr). On the software, the volume model was peeled at 1 mm thicknesses and rotated at 30 degrees. Since the volume models were made from the cadaveric images, actual colors of the structures were displayed in high resolution. Thanks to the segmentation data, the structures on the volume model could be automatically annotated. Using the software, the sternocleidomastoid muscle and the internal jugular vein in the neck region, the cubital fossa in the upper limb region, and the femoral triangle in the lower limb region were observed to be described. CONCLUSION: For the students learning various medical procedures, the software presents the needed graphic information of the human body. The curved sectional planes are expected to be a tool for disciplinary convergence of the sectional anatomy and surface anatomy.
Anatomy, Cross-Sectional ; Cadaver* ; Comprehension ; Education ; Human Body ; Humans ; Imaging, Three-Dimensional ; Jugular Veins ; Learning ; Lower Extremity ; Male* ; Neck ; Upper Extremity ; Visible Human Projects

BACKGROUND: Virtual environments have brought the use of realistic training closer to many different fields of education. In medical education, several visualization methods for studying inside the human body have been introduced as a way to verify the structure of internal organs. However, these methods are insufficient for realistic training simulators because they do not provide photorealistic scenes or offer an intuitive perception to the user. In addition, they are used in limited environments within a classroom setting. METHODS: We have developed a virtual dissection exploration system that provides realistic three-dimensional images and a virtual endoscopic experience. This system enables the user to manipulate a virtual camera through a human organ, using gesture-sensing technology. We can make a virtual dissection image of the human body using a virtual dissection simulator and then navigate inside an organ using a virtual endoscope. To improve the navigation performance during virtual endoscopy, our system warns the user about any potential collisions that may occur against the organ's wall by taking the virtual control sphere at the virtual camera position into consideration. RESULTS: Experimental results show that our system efficiently provides high-quality anatomical visualization. We can simulate anatomic training using virtual dissection and endoscopic images. CONCLUSION Our training simulator would be helpful in training medical students because it provides an immersive environment.

BACKGROUND: The hand anatomy, including the complicated hand muscles, can be grasped by using computer-assisted learning tools with high quality two-dimensional images and three-dimensional models. The purpose of this study was to present up-to-date software tools that promote learning of stereoscopic morphology of the hand. METHODS: On the basis of horizontal sectioned images and outlined images of a male cadaver, vertical planes, volume models, and surface models were elaborated. Software to browse pairs of the sectioned and outlined images in orthogonal planes and software to peel and rotate the volume models, as well as a portable document format (PDF) file to select and rotate the surface models, were produced. RESULTS: All of the software tools were downloadable free of charge and usable off-line. The three types of tools for viewing multiple aspects of the hand could be adequately employed according to individual needs. CONCLUSION: These new tools involving the realistic images of a cadaver and the diverse functions are expected to improve comprehensive knowledge of the hand shape.
Anatomy, Regional ; Cadaver ; Computer-Assisted Instruction ; Hand Strength ; Hand ; Humans ; Learning ; Male ; Muscles ; Visible Human Projects

BACKGROUND: Virtual environments have brought the use of realistic training closer to many different fields of education. In medical education, several visualization methods for studying inside the human body have been introduced as a way to verify the structure of internal organs. However, these methods are insufficient for realistic training simulators because they do not provide photorealistic scenes or offer an intuitive perception to the user. In addition, they are used in limited environments within a classroom setting.METHODS: We have developed a virtual dissection exploration system that provides realistic three-dimensional images and a virtual endoscopic experience. This system enables the user to manipulate a virtual camera through a human organ, using gesture-sensing technology. We can make a virtual dissection image of the human body using a virtual dissection simulator and then navigate inside an organ using a virtual endoscope. To improve the navigation performance during virtual endoscopy, our system warns the user about any potential collisions that may occur against the organ's wall by taking the virtual control sphere at the virtual camera position into consideration.RESULTS: Experimental results show that our system efficiently provides high-quality anatomical visualization. We can simulate anatomic training using virtual dissection and endoscopic images.CONCLUSION: Our training simulator would be helpful in training medical students because it provides an immersive environment.

OBJECTIVE: There are few reports on the clinical outcomes of the percutaneous endoscopic lumbar discectomy(PELD) with laser for the treatment of far lateral lumbar disc herniation. The objective of this study is to assess the safety and efficacy of the PELD with laser for the treatment of far lateral lumbar disc herniation. METHODS: The clinical records of 42 patients who had far lateral lumbar disc herniation and underwent PELD with laser between January 1996 and August 2002 were analyzed retrospectively. There were 24(57.1%) males and 18(42.9%) females, with a mean age of 53(range, 26-73) years. The surgical procedure was performed via a posterolateral approach after induction of a local anesthesis. The clinical outcomes were measured with MacNabO s criteria. The mean follow-up period was 38(range, 5-77) months. RESULTS: Clinical outcomes were revealed as follows: excellent in 28 patients(66.7%); good in 11(26.2%); fair in 2(4.7%); and poor in 1(2.4%). Therefore, the percentage of successful(excellent and good) outcomes was 92.9%. There was no statistically significant variation in the success rates according to age and operation level(p>0.05). Before the introduction of the high resolution endoscope, the success rate was 90.3% but after upgrading to the high resolution endoscope, the success rate was 100%, and there was a statistically significant variation in the success rate(p<0.05). In all cases, there was no complication or recurrence. CONCLUSION: As a minimally invasive surgery, PELD with laser is a safe and efficacious procedure for the treatment of far lateral disc herniation.
Diskectomy* ; Endoscopes ; Female ; Follow-Up Studies ; Humans ; Male ; Recurrence ; Retrospective Studies ; Surgical Procedures, Minimally Invasive

Unlike volume models, surface models, which are empty three-dimensional images, have a small file size, so they can be displayed, rotated, and modified in real time. Thus, surface models of male urogenital organs can be effectively applied to an interactive computer simulation and contribute to the clinical practice of urologists. To create high-quality surface models, the urogenital organs and other neighboring structures were outlined in 464 sectioned images of the Visible Korean male using Adobe Photoshop; the outlines were interpolated on Discreet Combustion; then an almost automatic volume reconstruction followed by surface reconstruction was performed on 3D-DOCTOR. The surface models were refined and assembled in their proper positions on Maya, and a surface model was coated with actual surface texture acquired from the volume model of the structure on specially programmed software. In total, 95 surface models were prepared, particularly complete models of the urinary and genital tracts. These surface models will be distributed to encourage other investigators to develop various kinds of medical training simulations. Increasingly automated surface reconstruction technology using commercial software will enable other researchers to produce their own surface models more effectively.
Computer Simulation ; Humans ; Image Processing, Computer-Assisted ; Imaging, Three-Dimensional ; Male ; Research Personnel ; Urogenital System ; Visible Human Projects