• Journal of Internet Computing and Services
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• v.21 no.3
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• pp.103-111
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• 2020

Liver cancer is the most fatal cancer that occurs worldwide. In order to diagnose liver cancer, the patient's physical condition was checked by using a CT technique using radiation. Segmentation was needed to diagnose the liver on the patient's abdominal CT scan, which the radiologists had to do manually, which caused tremendous time and human mistakes. In order to automate, researchers attempted segmentation using image segmentation algorithms in computer vision field, but it was still time-consuming because of the interactive based and the setting value. To reduce time and to get more accurate segmentation, researchers have begun to attempt to segment the liver in CT images using CNNs, which show significant performance in various computer vision fields. The pixel value, or numerical value, of the CT image is called the Hounsfield Unit (HU) value, which is a relative representation of the transmittance of radiation, and usually ranges from about -2000 to 2000. In general, deep learning researchers reduce or limit this range and use it for training to remove noise and focus on the target organ. Here, we observed that the range of HU values was limited in many studies but different in various liver segmentation studies, and assumed that performance could vary depending on the HU range. In this paper, we propose the possibility of considering HU value range as a hyper parameter. U-Net and ResUNet were used to compare and experiment with different HU range limit preprocessing of CHAOS dataset under limited conditions. As a result, it was confirmed that the results are different depending on the HU range. This proves that the range limiting the HU value itself can be a hyper parameter, which means that there are HU ranges that can provide optimal performance for various models.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.5
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• pp.474-481
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• 2006

The endoscopic assisted approach for the treatment of condylar fracture is a less invasive alternative treatment modality and is considered to be able to overcome the limited access to the operation field to obtain an accurate reduction and fixation. Six patients with condylar neck and subcondylar fracture underwent the endoscopic assisted open reduction and internal fixation through the transoral approach at the Department of Oral and Maxillofacial Surgery, Seoul National University Dental Hospital. The endoscope was inserted through an intraoral incision and the reduction of fracture fragment was performed via a transbuccal approach with two transcutaneous stab incisions. Five patients showed anatomic reduction without any complications. One patient, whose fracture site was fixed with a single plate, showed displacement of fractured condylar segment during the follow up period. No patient had any facial nerve damage.

• Journal of Chest Surgery
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• v.53 no.6
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• pp.346-352
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• 2020

Background: We aimed to assess the clinical outcomes of patients who underwent surgical repair of Kommerell diverticulum (KD) with individualized surgical methods. Methods: A retrospective analysis was performed of adult patients (aged ≥17 years) who underwent surgery to treat KD between June 2008 and October 2019. Results: Nine patients (median age, 45 years; range, 19-67 years; 7 men) underwent surgical repair. The indications for surgical therapy were acute aortic dissection in 2 patients, the presence of compressive symptoms due to dilated KD in 4 patients, and aneurysm growth in 3 patients. Various surgical techniques were used: (1) resection of the diverticulum stump and revascularization of the aberrant subclavian artery (n=3), (2) one-stage total-arch replacement including the diverticulum segment (n=3), and (3) hybrid repair (n=3). Early mortality occurred in 1 case of hybrid repair. Transient paraparesis occurred in a patient who underwent total arch repair as part of complicated acute aortic dissection. During follow-up (median duration, 30 months; range, 7-130 months), no late death or associated aortic complications were documented. All survivors were free from symptoms and had no abnormal findings on follow-up computed tomography. Conclusion: With a customized surgical approach and appropriate consideration of patient-specific anatomy and associated comorbidities, KD can be repaired with favorable outcomes.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.5
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• pp.480-488
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• 2008

Orthodontists often treat cases which are difficult to treat with conventional orthodontics. In such cases, it could be treated with surgical procedures with the help of an oral surgeon. Especially, transverse deficiency of the mandible can be corrected by widening the transverse width of mandibular symphysis, using distraction osteogenesis. Transverse widening of mandibular sympysis is known as a safe treatment but still complications could occur during the treatment. We are reporting some complications of cases that mandibular symphysis transverse widening were applied. Some cases showed complications because of the inappropriate osteotomy line. Since straight vertical osteotomy line was inclined to the left, only the left bony segment was likely to expand. According to bio-mechanical considerations, it will be better to perform a step osteotomy, cutting the eccentric area of the alveolar crest and the centric area of the basal symphyseal area. Complications could also occur by the failure of the distraction device. The tooth borne distraction device was attached on the lingual side of the tooth with composite resin. During the distraction period, it was impossible to obtain appropriate distraction speed and rhythm because of frequent fall off of the distraction device. Therefore, distraction device should be attached firmly with orthodontic band or bone screw, etc. Tooth mobility increasement could also occur as a complication. 'Walking teeth phenomenon' was observed during the distraction period, showing severe teeth mobility and pain during mastication. These symptoms fade out during the consolidation period. Since the patient could feel insecure and uncomfortable, it should be notified to the patient before the procedure. Finally, alveolar crestal bone loss could occur. Alveolar crestal bone loss occurred because of lack of distraction device firmness and teeth trauma caused by lower lip biting habit. Therefore, adequate firmness of the distraction device and habit control will be needed.

• Journal of Chest Surgery
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• v.32 no.2
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• pp.185-188
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• 1999

The pulmonary giant cell carcinoma is classified as a variant of a large cell carcinoma and is diagnosed by the minimum component of 10% huge, pleomorphic and multinucleated giant tumor cell and emperipolesis of the neutrophils into the tumor cells. This tumor is characterized by local recurrences and early metastasis with extremely short patient survival. However, there are some reports that state that the survival time was extended by the operative resection and postoperative adjuvant chemotherapy and radiotherapy. A 46-year old male was admitted with complaint of hemoptysis for 2 months. Through chest X-ray and chest CT, a 5cm sized mass was found in the apical segment of the right upper lobe. During the preoperative evaluation, stenotic lesion in the left anterior descending coronary artery was found and treated by percutaneous transarterial coronary angioplasty. Four weeks later, right upper lobectomy was performed and the mass was proven to be a giant cell carcinoma. The patient received adjuvant chemotherapy and radiotherapy.

• Tuberculosis and Respiratory Diseases
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• v.67 no.2
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• pp.131-134
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• 2009

Pulmonary papillomas are rare benign epithelial neoplasms arising in bronchial surface epithelium. They are categorized by a variety of cell types including squamous, glandular, and mixed squamous and glandular type. Among them, glandular papilloma is extremely rare and has not been reported in Korea. The patient was a 52 year-old man presenting with a 4-months' history of recurrent hemoptysis. Bronchofiberoscopy revealed a whitish, glistening, and polypoid mass lesion at the proximal bronchus in the basal segment of the left lower lung. Bronchoscopic biopsy was performed; papillary fronds lined by ciliated or nonciliated pseudostratified columnar epithelium were noted on histologic findings. We present the first case of glandular papilloma in Korea. Two years later, the patient visited our hospital again due to hemoptysis. On follow-up bronchoscopy, a mass that had been found previously showed an increase in size.

• Tuberculosis and Respiratory Diseases
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• v.74 no.5
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• pp.231-234
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• 2013

Aspergillus causes a variety of clinical syndromes in the lung including tracheobronchial aspergillosis, invasive aspergillosis, chronic necrotizing pulmonary aspergillosis, allergic bronchopulmonary aspergillosis, and aspergilloma. Aspergilloma usually results from ingrowths of colonized Aspergillus in damaged bronchial tree, pulmonary cyst or cavities of patients with underlying lung diseases. There are a few reports on endobronchial aspergilloma without underlying pulmonary lesion. We have experienced a case of endobronchial aspergilloma associated with foreign body developed in an immunocompetent patient without underlying lung diseases. A 59-year-old man is being hospitalized with recurring hemoptysis for 5 months. X-ray and computed tomography scans of chest showed a nodular opacity in superior segment of left lower lobe. Fiberoptic bronchoscopy revealed an irregular, mass-like, brownish material which totally obstructed the sub-segmental bronchus and a foreign body in superior segmental bronchus of the lower left lobe. Histopathologic examinations of biopsy specimen revealed fungal hyphae, characteristic of Aspergillus species.

• Archives of Plastic Surgery
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• v.47 no.6
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• pp.613-618
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• 2020

The surgical treatment of extensive urethral strictures remains a controversial topic; although techniques have evolved, there is still no definite method of choice. Since 1968, when Orandi presented an original technique for one-stage urethroplasty using a penile skin flap, the Orandi technique has become the most prevalently used one-stage procedure for anterior urethral strictures. We present a 20-year follow-up experience with one-stage reconstruction of long urethral strictures using a longitudinal ventral tubed flap of penile skin, with some important technical changes to Orandi's original technique to overcome the deficient vascularity caused by periurethral scar tissue. In 1997, a 55-year-old male patient complained of severe voiding difficulty and a weak urinary stream because of transurethral resection of the prostate due to benign prostatic hyperplasia. Another 47-year-old male patient had the same problem due to self-removal of a Foley catheter in 2002. In both patients, a urethrogram demonstrated extensive strictures involving the long segment of the anterior urethra. A rectangular skin flap on the ventral surface of the penis was used considering the appropriate length, diameter, and depth of the neourethra. The modified Orandi flap provided a pedicled strip of penile skin measuring an average of 8 cm. The mean duration of follow-up was 20.5 years. A long-term evaluation revealed stable performance characteristics without any complications.

• Journal of Chest Surgery
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• v.40 no.5 s.274
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• pp.380-383
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• 2007

A 42-years-old man was referred to our department due to his hemoptysis. Chest CT showed a cavitary lung lesion in the apical segment of the RUL and an anterior mediastinal mass. The patient underwent wedge resection for the cavitary lesion and complete resection for the mediastinal mass. The pathologic finding was Paragonimus Westermani infestation in both the lung and thymus. The abdomen CT taken postoperatively showed an inflammatory mass involving the transverse colon and a small nodular lesion around the descending colon, which strongly suggested paragonimiasis. Postoperatively, the patient took Praziquantel for 2 days and he was discharged without any complications. There was no evidence of recurrence for the last 2 years.

• Journal of Chest Surgery
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• v.50 no.2
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• pp.133-136
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• 2017

A 27-year-old female patient was referred due to an edematous left lower extremity. Both saphenous veins had been ablated with an endovenous laser procedure used to treat varicose veins. Venography revealed that the left common femoral vein had been divided and that thrombosis was present at the site of division. No veins were available around the thighs. The patient was treated using a staged procedure. During the first stage, a ringed polytetrafluoroethylene graft was used to repair the common femoral vein, and an arteriovenous fistula was constructed from the femoral artery to the graft using a short segment of cephalic vein to increase graft patency. The edema was relieved postoperatively and the graft was patent. During the second stage, which was performed 6 months later, the fistula was occluded by coil embolization. The staged procedure described herein provides an alternative for venous reconstruction when autologous vein is unavailable.