• 대한의용생체공학회:의공학회지
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• 제7권2호
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• pp.113-116
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• 1986

We investigated the structural geometry of thirty-eight Korean femurs. The purpose of this study is to identify major geometrical differences between Korean femurs 3nd others that we believe belong to Caucasians so that we would be able to get insights into the femoral component design that fits Asians including Koreans. We utilized computerized tomography (CT) images of femurs extracted from cadavers. The CT images were transformed into bitmap data by using a film scanner, and then analyzed by using a commercially available software called Image v.1.0 and a Macintosh IIci computer.The resulting data were compared with already published data. The major results show that the geometry of the Korean femurs is significantly different from that of Caucasians: (1) the anteversion angle and the canal flare index are greater by the amount of approximately 8˚ and 0.5, respectively, (2) the shape of the isthmus cross section is more round, and (3) the distance between the teaser trochanter and the proximal border of the isthmus is shelter by about 15 mm. The results suggested that the femoral component suitable for Asians should be different from the currently-used components designed and manufactured mostly by European or American companies.

• 제어로봇시스템학회논문지
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• 제17권10호
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• pp.1044-1050
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• 2011

The quality of brazing joints is one of the most important factors that have an effect on the performance of the brazing joint-based heat exchangers with the growing use in industry recently. Therefore, it is necessary to inspect the brazing joints in order to guarantee the performance of the heat exchangers. This paper presents a non-destructive method to inspect the brazing joints of the heat exchangers using X-ray. Firstly, X-ray cross-sectional images of the brazing joints are obtained by using CT (Computerized Tomography) technology. Cross-sectional image from CT is more useful to detect the inner defects than the traditional transmitted X-ray image. Secondly, the acquired images are processed by an algorithm proposed for the defect detection of brazing joint. Finally, two types of brazing joint are examined in a series of experiments to detect the defects in brazing joints. The experimental results show that the proposed algorithm is effective for defect detection of the brazing joints in heat exchangers.

• Journal of Korean Neurosurgical Society
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• 제66권5호
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• pp.552-561
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• 2023

Objective : A chronic subdural hematoma (CSDH) is a collection of bloody fluid located in the subdural space and encapsulated by neo-membranes. An inner subdural hygroma (ISH) is observed between the inner membrane of a CSDH and the brain surface. We present six cases of CSDH combined with ISH treated via endoscopy. Methods : Between 2011 and 2022, among the 107 patients diagnosed with CSDH in our institute, six patients were identified as presenting with CSDH combined with ISH and were included in this study. Preoperative computerized tomography (CT) and magnetic resonance imaging (MRI) were performed simultaneously, and endoscopic surgery for aspiration of the hematoma was performed in all cases of CSDH combined with ISH. Results : The mean age of patients was 71 years (range, 66 to 79). The patients were all male. In two cases, the ISH was not identified on CT, but was clearly seen on MRI in all patients. The inner membrane of the CSDH was tense and bulging after draining of the CSDH in endoscopic view due to the high pressure of the ISH. After fenestration of the inner membrane of the CSDH and aspiration of the ISH, the membrane was sunken down due to the decreasing pressure of the ISH. There was one recurrence in post-operative 2-month follow up. The symptoms improved in all patients after surgery, and there were no surgery-related complications. Conclusion : CSDH combined with ISH can be diagnosed on imaging, and endoscopic surgery facilitates safe and effective treatment.

• 한국정밀공학회지
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• 제24권9호
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• pp.140-147
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• 2007

As the use of robots in surgeries becomes more frequent, the registration of medical devices based on images becomes more important. This paper presents two numerical algorithms for the registration of cross-sectional medical images such as CT (Computerized Tomography) or MRI (Magnetic Resonance Imaging) by using the geometrical information from helix or line fiducials. Both registration algorithms are designed to be used for a surgical robot that works inside a cavity of human body. This paper also reports details about the fiducial pattern that includes four helices and one line. The algorithms and the fiducial pattern were tested in various computer-simulated situations, and the results showed excellent overall registration accuracy.

• 대한세포병리학회지
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• 제3권2호
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• pp.100-103
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• 1992

We experienced a case of primary hepatic actinomycosis which was initially diagnosed by means of fine needle aspiration. The patient was a 31-year-old emaciated man with a 2-month history of 10 kg weight loss, right upper quadrant pain and flank pain. The liver was palpable and tender on physical examination. Computerized tomography scan of the liver showed two ill-defined hypodense masses in gallbladder fossa and inferior pole of right lobe. Hepatocellular carcinoma was clinically suspected. A CT-guided fine needle aspiration was peformed. Microscopically, smears showed numerous radiating clusters of filamentous bacteria with many neutrophils and monocytes in necrotic background. The symptoms were improved by incision and drainage and massive administration of penicillin.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.714-719
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• 2004

This paper presents two numerical algorithms for registration of cross-sectional medical images such as CT (Computerized Tomography) or MRI (Magnetic Resonance Imaging) by using geometrical information from helix or line fiducials. The registration algorithms are designed to be used for a surgical robot working inside cavities of human body. A cylindrical device with a combination of line and helix fiducials were also devised and is supposed to be attached to the end-effector of surgical robot. The algorithms and the fiducial pattern were tested in various computer-simulated situations, and the results indicate excellent overall registration accuracy.

• Journal of Korean Neurosurgical Society
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• 제40권5호
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• pp.377-380
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• 2006

Intradiploic epidermoid cysts of the cranium are rare, benign and slow growing lesion. However, these cysts may cause neurologic deficits due to mass effect. Intradiploic epidermoid cysts are thought to be derived from persistent ectodermal remnants present in the cranial bones during embryogenic development. Here, we report a case of an occipital intradiploic epidermoid cyst with posterior fossa extension. The patient developed intracranial hypertension associated with hydrocephalus due to aqueductal stenosis, and venous congestion secondary to compression of the torcular and the transverse sinus. The imaging studies included a computerized tomography[CT] venogram, which is essential for determining the pathophysiological mechanism of the clinical spectrum and for surgical planning. Near total removal was accomplished and the postoperative course was uneventful. Postoperative imaging studies demonstrated a reversal of the neural structures, but no patency of the sinus, which was presumably indicative of prolonged sinus stenosis. The patient gradually improved and was discharged free of symptoms.

• ETRI Journal
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• 제28권1호
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• pp.107-110
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• 2006

The dimensions of the human body vary by age, sex, and race. The internal structure and outer dimensions of a body exposed to an electromagnetic field is important for accurate dosimetry. The average physical size of Korean adult males between the ages 18 to 24 was investigated, and a male volunteer was selected whose physical condition is within the physical standards, ${\pm}5%$. Magnetic resonance images and partially computerized tomography images of the volunteer were acquired. The intervals between the transverse images were 1 mm for the head and 3 mm for the rest of the body. About 30 different tissues were manually classified by an anatomist on the raw images, and the segmented images were implemented in the form of a text file appropriate for numerical formulation.

• Journal of Trauma and Injury
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• 제28권4호
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• pp.262-265
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• 2015

An arteriovenous fistula (AVF) from the renal artery following a penetrating abdominal trauma is not common. We report the case of a 19-year-old male who presented with a knife stab wound in the right upper quadrant. Due to unstable vital signs and to the protrusion of the mesentery through the stab wound, providing definite evidence of peritoneal violation, an emergent exploratory laparotomy was carried out. There were injuries at the proximal transverse mesocolon and the second portion of the duodenum, with bile leakage. There was also a mild amount of retroperitoneal hematoma near the right kidney, without signs of expansion or pulsation. The mesocolon and the duodenum were repaired. After the operation, abdominal computerized tomography (CT) was performed, which revealed contrast from the right renal artery shunting directly into the vena cava. Transcatheter arterial embolization with a coil and vascular plug was performed, and the fistula was repaired. The patient recovered completely and was discharged without complication. For further and thorough evaluation of an abdominal trauma, especially one involving the retroperitoneum, a CT scan is recommended, when possible, either prior to surgery or after surgery when the patient is stabile. Furthermore, a lateral retroperitoneal hematoma and an AVF after a penetrating trauma may not always require exploration. Sometimes, it may be safely treated non-operatively or with embolization.

• Imaging Science in Dentistry
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• 제40권4호
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• pp.171-178
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• 2010

Purpose : The purpose of this study is to develop a surgical stent for dental implant procedure that can be easily applied and affordable by using cone beam computerized tomography (CBCT). Materials and Methods : Aluminum, Teflon-PFA (perfluoroalkoxy), and acetal (polyoxymethylene plastic) were selected as materials for the surgical stent. Among these three materials, the appropriate material was chosen using the CBCT images. The surgical stent, which could be easily placed into an oral cavity, was designed with chosen material. CBCT images of the new surgical stent on mandible were obtained using Alphard-3030 dental CT system (Asahi Roentgen Co., Ltd., Kyoto, Japan). The point of insertion was prescribed on the surgical stent with the multiplanar reconstruction software of OnDemand3D (CyberMed Inc., Seoul, Korea). Guide holes were made at the point of insertion on the surgical stent using newly designed guide jig. CBCT scans was taken for the second time to verify the accuracy of the newly designed surgical stent. Results : Teflon-PFA showed radiologically excellent image characteristics for the surgical stent. High accuracy and reproducibility of implantation were confirmed with the surgical stent. Conclusion : The newly designed surgical stent can lead to the accurate implantation and achieve the clinically predictable result.