• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.4
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• pp.262-269
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• 2010

Introduction: Accurate diagnosis and treatment planning are very important for orthognathic surgery. A small error in diagnosis can cause postoperative functional and esthetic problems. Pre-existing 2-dimensional (D) chephalogram analysis has a high likelihood of error due to its intrinsic and extrinsic problems. A cephalogram can also be inaccurate due to the limited anatomic points, superimposition of the image, and the considerable time and effort required. Recently, an improvement in technology and popularization of computed tomography (CT) provides patients with 3-D computer based cephalometric analysis, which complements traditional analysis in many ways. However, the results are affected by the experience and the subject of the investigator. Materials and Methods: The effects of the sources human error in 2-D cephalogram analysis and 3-D computerized tomography cephalometric analysis were compared using Simplant CMF program. From 2008 Jan to 2009 June, patients who had undergone CT, cephalo AP, lat were investigated. Results: 1. In the 3 D and 2 D images, 10 out of 93 variables (10.4%) and 11 out 44 variables (25%), respectively, showed a significant difference. 2. Landmarks that showed a significant difference in the 2 D image were the points frequently superimposed anatomically. 3. Go Po Orb landmarks, which showed a significant difference in the 3 D images, were found to be the artificial points for analysis in the 2 D image, and in the current definition, these points cannot be used for reproducibility in the 3 D image. Conclusion: Generally, 3-D CT images provide more precise identification of the traditional cephalometric landmark. Greater variability of certain landmarks in the mediolateral direction is probably related to the inadequate definition of the landmarks in the third dimension.

• Journal of the Korean Society of Physical Medicine
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• v.16 no.3
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• pp.81-87
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• 2021

PURPOSE: This study compared the cross-sectional areas (CSA) of the cervical muscles of straight neck patients and normal participants during a craniocervical flexion exercise (CCFE) using computerized tomography (CT) to investigate the effects of CCFE on the cervical curve. METHODS: Eighteen subjects were recruited for this study. Nine subjects were allocated to the straight neck group (subjects with pain and a cervical lordosis angle of less than 20°); the remainder formed the control group (subjects with a cervical lordosis angle greater than 20°). The CSA of the subjects' neck flexors (longus colli, longus capitis, and sternocleidomastoid) were measured by CT during rest and CCFE in the supine position, and the range of motion (ROM) of neck flexion was measured using a C-ROM instrument in a sitting. RESULTS: The straight neck group had a significantly smaller CSA of the longus colli, longus capitis, and sternocleidomastoid than the control group (p < .05). Both the straight neck and control groups showed statistically significant increases in the CSA of the neck flexors during CCFE compared to that at rest (p < .05). In addition, the straight neck group showed a significantly smaller ROM of neck flexion than the control group (p < .05). CONCLUSION: The results of this study provide more concrete evidence for therapists by demonstrating that CCFE improves the neck function by strengthening the neck flexors and increasing the neck stability for straight neck patients. Therefore, it is necessary to perform CCFE and neck extension exercises to rehabilitate straight neck patients.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.6
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• pp.566-574
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• 2006

Purpose : This study was performed to provide an anatomical information of the mandibular ramus for the successful inferior alveolar nerve block. Three dimensional images were reconstructed from the computerized tomography (CT) and the anatomical evaluation of the mandibular ramus was done. Materials and methods : Sixty-four patients who had been taken the facial CT scans from 2000, Jan to 2003, June was selected. The patients who had the anterior or posterior teeth misssing, edentulous ridge, and jaw fracture were excepted. In the occulusal plane, the lingual surface angle (LSA) between the mid-sagittal plane and the mandibular molar lingual surface from the 2nd premolar to the 2nd molar, the inner ramal surface angle (IRSA), the maximum inner ramal surface angle (MxIRSA), and the outer ramal surface angle (ORSA) to the-mid sagittal plane were measured. The inner ramal surface angle in the ligular tip level (IRSA-L) and the outer ramal surface angle in the ligular tip level (ORSA-L), the ramal length (RL), and the anterior ramal length (ARL) were also measured in the lingular tip level. Results : In the lingular tip level, the mean IRSA-L and ORSA-L were $28.6{\pm}6.3^{\circ}$ and $17.9{\pm}4.9^{\circ}$ respectively. The larger was the IRSA, the larger was the ORSA. In the lingular tip level, the mean ramal length was 35.8${\pm}$3.4 mm. The larger was the IRSA-L, the shorter was the ramal length. On the lingular tip level, the mean anterior ramal length from anterior ramus to lingular tip was 19.6${\pm}$3.3 mm. when the ramal length was longer, the anterior ramal length was also longer. On the lingular tip level, there was positive correlation vetween the IRSA and the ORSA, negative correlation between the IRSA and the ramal length, and positive correlation between the ramal length and the lingular tip level to the anterior ramus. There was no statistical meaning of data between sex and age. Conclusion : In the clinical view of the results so far achieved, if the direction of needle is closer to posterior it is able to contact bone on lingular tip when the internal surface of ramus is wided outer.

• The Transactions of the Korea Information Processing Society
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• v.5 no.12
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• pp.3275-3284
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• 1998

In this paper, we deseribe a Medical Image Information System. Our system stores and manages 5 dimensional medical image data and provides the 3 dimensional medical data via the Internet. The Internet standard VR format. VRML(Virtual Reality Modeling Language) is used to represent the 3I) medical image data. The 3D images are reconstructed from medical image data which are enerated by medical imaging systems such ans CT(Computerized Tomography). MRI(Magnetic Resonance Imaging). PET(Positron Emission Tomograph), SPECT(Single Photon Emission Compated Tomography). We implemented the medical image information system shich rses a surface-based rendering method for the econstruction of 3D images from 2D medical image data. In order to reduce the size of image files to be transfered via the Internet. The system can reduce more than 50% for the triangles which represent the surfaces of the generated 3D medical images. When we compress the 3D image file, the size of the file can be redued more than 80%. The users can promptly retrieve 3D medical image data through the Internet and view the 3D medical images without a graphical acceleration card, because the images are represented in VRML. The image data are generated by various types of medical imaging systems such as CT, MRI, PET, and SPECT. Our system can display those different types of medical images in the 2D and the 3D formats. The patient information and the diagnostic information are also provided by the system. The system can be used to implement the "Tele medicaine" systems.

• Journal of the Korean Society of Radiology
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• v.2 no.3
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• pp.5-9
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• 2008

In the computerized tomography(CT), various filters are using in the reconstruction algorithm to reduce or eliminate the artifacts which are intrinsically induced by the imperfection of mathematical methods for reconstruction, lack of real informations about anatomic structures in the projection image, errors in data acquisition and so on. Hann filter was used to evaluate the filter effects on the elimination of reconstruction artifact in the CT image. The quantitative study was done by changing cut-off frequency of Hann filter from 0.1 to 0.9 with frequency increasement by 0.2. NPS analysis was fulfilled for the quantitative evaluation of filter effect.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.184-187
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• 2002

Two-dimensional (2-D) X-ray computerized tomography (CT) equipments are widely used in industrial and medical fields, and nowadays studies on reconstruction algorithm for 3-D cone-beam acquisition systems are active for better utilization. The authors recent-By have proposed a fast reconstruction aigorithm using tree-structured filter bank for 2-D C1, and shown the algorithm is applicable to an approximate reconstruction of 3-D CT. For exact 3-D CT reconstruction, however, we have to backproject 1-D signal into 3-D space. This paper proposes a fast implementation method for this back-projection by use of tree-structured filter bank. and shows the proposed method works approximately 700 times faster than the direct one with almost same reconstruction image quality.

• Journal of Gastric Cancer
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• v.10 no.4
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• pp.254-258
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• 2010

Gastric lipomatosis is an extremely rare condition. We present a case of a 69-year-old woman admitted with epigastric soreness. Computerized tomography (CT) revealed extrinsically compressing, fat-containing mass lesions on the entire gastric wall of the antrum and body except for the lesser curvature. A subtotal gastrectomy was performed. Pathology findings confirmed a gastric lipomatosis with multiple gastric ulcerations and extensive disruptions of the muscular layers. This case and reports of other gastric lipomatosis cases indicate that CT should be used to characterize large submucosal masses because CT can show the specific nature and extent of the disease. We believe that surgical treatment is the most appropriate treatment for symptomatic gastric lipomatosis that shows extensive gastric involvement, or when there are multiple gastric lipomas.

• Korean Journal of Biological Psychiatry
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• v.2 no.1
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• pp.38-43
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• 1995

The application of neuroimaging techniques in psychiatry started in 1970s with the use of CT(computerized tomography). Neuroimaging methods can be categorized as anatomical and functional. Recently, attentions are focused on the functional neuroimaging methods those could give us various important informations. But results regarding to psychotropic medication effect on neuroimaging are not sufficient. Here, the study results of the medication effect with the functional imaging methods are mainly revieued.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.05
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• pp.465-468
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• 1997

A Study on Computer Assisted Diagnosis (CAD) system extract ing lung cancer part from Digital X-ray Computerized Tomography(CT) image is discussed in this paper. It is very crucial to segment the image of lung into the three organ area such as inside, outside and the hilum so that the variant image processing algorithm can be applied an each area respectively. In this paper, the efficient algorithm extracting lung cancer part is proposed with characterizing lung hilum part and its associated vessel patterns.

• Journal of Korean Neurosurgical Society
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• v.37 no.1
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• pp.59-62
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• 2005

We describe two cases of tension pneumocephalus, one caused by ventriculoperitoneal shunt for communicating hydrocephalus, and the other caused by craniocerebral trauma. In the first case report, we examined the relationship between cerebrospinal fluid leakage and delayed onset tension pneumocephalus. The second case report, we addressed issues such as the diagnosis, management, and pathogenesis, as well as computerized tomography(CT) findings.