• Korean Journal of Radiology
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• v.22 no.3
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• pp.344-353
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• 2021

Objective: The mitotic count of gastrointestinal stromal tumors (GIST) is closely associated with the risk of planting and metastasis. The purpose of this study was to develop a predictive model for the mitotic index of local primary GIST, based on deep learning algorithm. Materials and Methods: Abdominal contrast-enhanced CT images of 148 pathologically confirmed GIST cases were retrospectively collected for the development of a deep learning classification algorithm. The areas of GIST masses on the CT images were retrospectively labelled by an experienced radiologist. The postoperative pathological mitotic count was considered as the gold standard (high mitotic count, > 5/50 high-power fields [HPFs]; low mitotic count, ≤ 5/50 HPFs). A binary classification model was trained on the basis of the VGG16 convolutional neural network, using the CT images with the training set (n = 108), validation set (n = 20), and the test set (n = 20). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated at both, the image level and the patient level. The receiver operating characteristic curves were generated on the basis of the model prediction results and the area under curves (AUCs) were calculated. The risk categories of the tumors were predicted according to the Armed Forces Institute of Pathology criteria. Results: At the image level, the classification prediction results of the mitotic counts in the test cohort were as follows: sensitivity 85.7% (95% confidence interval [CI]: 0.834-0.877), specificity 67.5% (95% CI: 0.636-0.712), PPV 82.1% (95% CI: 0.797-0.843), NPV 73.0% (95% CI: 0.691-0.766), and AUC 0.771 (95% CI: 0.750-0.791). At the patient level, the classification prediction results in the test cohort were as follows: sensitivity 90.0% (95% CI: 0.541-0.995), specificity 70.0% (95% CI: 0.354-0.919), PPV 75.0% (95% CI: 0.428-0.933), NPV 87.5% (95% CI: 0.467-0.993), and AUC 0.800 (95% CI: 0.563-0.943). Conclusion: We developed and preliminarily verified the GIST mitotic count binary prediction model, based on the VGG convolutional neural network. The model displayed a good predictive performance.

• Clinical and Experimental Pediatrics
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• v.46 no.4
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• pp.385-388
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• 2003

Pulmonary sequestration is a rare congenital mass of nonfunctional pulmonary tissue that lacks a normal-connection with the bronchial tree or the pulmonary arteries. It is clinically asymptomatic but when it is complicated with recurrent infection, it needs to be treated. Conventionally, surgical removal was recommended, but these days we are trying new and less invasive techniques, such as arterial embolization. There were several reports about successful cases of pulmonary sequestration treated by embolization, but mostly all of them were done to newborns or infants. We report a case of a 15-year-old boy with an asymptomatic pulmonary sequestration on whom was performed coil embolization, and in the follow-up computed tomography(CT), the size of the lesion was decreased. He did not suffer severe respiratory symptoms.

• Journal of Korean Neurosurgical Society
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• v.48 no.1
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• pp.73-78
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• 2010

Objective : Streptococcus pyogenes is a beta-hemolytic bacterium that belongs to Lancefield serogroup A, also known as group A streptococci (GAS). There have been five reported case in terms of PubMed-based search but no reported case of brain abscess caused by Streptococcus pyogenes as a result of penetrating skull injury. We present a patient who suffered from penetrating skull injury that resulted in a brain abscess caused by Streptococcus pyogenes. Methods : The patient was a 12-year-old boy who fell down from his bicycle while cycling and ran into a tree. A wooden stick penetrated his skin below the right lower eyelid and advanced to the cranium. He lost consciousness on the fifth day of the incident and his body temperature was measured as $40^{\circ}C$. While being admitted to our hospital, a cranial computed tomography revealed a frontal cystic mass with a perilesional hypodense zone of edema. There was no capsule formation around the lesion after intravenous contrast injection. Paranasal CT showed a bone defect located between the ethmoidal sinus and lamina cribrosa. Results : Bifrontal craniotomy was performed. The abscess located at the left frontal lobe was drained and the bone defect was repaired. Conclusion : Any penetrating lesion showing a connection between the lamina cribrosa and ethmoidal sinus may result in brain abscess caused by Streptococcus pyogenes. These patients should be treated urgently to repair the defect and drain the abscess with appropriate antibiotic therapy started due to the fulminant course of the brain abscess caused by this microorganism.

• 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.

• 한국균학회소식:학술대회논문집
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• 2014.10a
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• pp.36-36
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• 2014

Apple blotch, caused by Marssonina coronaria, induce early defoliation in apple and leading to critical economic losses in apple orchards in Korea. Since M. coronaria is difficult to culture, we developed isolation and cultural method. We collected M. coronaria isolates from Gyeongbuk Province and then constructed phylogentic tree based on ITS regions. As the results, phylogenetic relationship indicated that all Korean isolates formed a same cluster and closely related to Chinese isolates [1]. Ecological characteristic of M. coronaria have been observed in apple orchards which located in Gyeongbuk Province from 2011 to present. As the results, the typical apple blotch symptoms were observed from July, and then the infected leaves were discolored and formed acervuli on the leaves. After rainfall, severe infection of symptoms such as discoloration and early defoliation were continuously observed until October. Also overwintered conidia were observed in next March on the fallen diseased leaves [2]. In the last 5 years, ascopores of M. coronaria were not observed in apple orchards which were severely infected by M. coronaria in Korea. Thus, it is assumed that overwintered conidia could be a primary inoculum of M. coronaria. Meanwhile, apple blotch has long latent periods compare to other apple disease. During the latent period, early diagnosis of apple blotch is the most important to control the disease by spray fungicide. In this reason, we developed novel diagnostic method to detect M. coronaria during latent period using optical coherence tomography (OCT) and Loop-mediated isothermal amplification (LAMP) method [2, 3]. In this presentation, it will introduce ecological characterization of M. coronaria in Korea and unique detection technique of M. coronaria in apple. It will be helpful to develop new strategies to control apple blotch in Korea.

• Tuberculosis and Respiratory Diseases
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• v.42 no.5
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• pp.760-766
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• 1995

Tracheopatbia osteoplastica is a rare disease of unknown cause and characterized by cartilaginous or bony projection into the tracheobronchial lumen, usually not involved posterior membranous portion of tracheobronchial tree. In the past, most of the cases were diagnosed incidentally at autopsy. But after the introduction of bronchoscopy and computed tomography, antemortem diagnosis was reported. Because of initial presenting symptoms were indolent and non-specific, misdiagnosis was reported frequently and correct diagnosis was delayed usually. We report two cases of tracheopatbia osteoplastica diagnosed by fiberoptic bronchoscopic biopsy.

• Tuberculosis and Respiratory Diseases
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• v.67 no.5
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• pp.467-470
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• 2009

A traumatic pulmonary pseudocyst is a rare complication of blunt thoracic trauma. The clinical symptoms and signs are similar to other respiratory diseases, such as pulmonary tuberculosis. Therefore, a trauma history with the resulting radiologic and clinical findings is important for making a diagnosis. A 26-year-old male was admitted to our hospital due to cough for 3 days. The chest x-ray revealed diffuse infiltrations and a cavitary lesion at the left lung. His left chest had hit a tree as a result of motorcycle accident one day before admission. Initially, it was assumed that his symptoms and chest X-ray might be due to a tuberculosis infection. However, bronchoscopy revealed old blood clots at both lungs, particularly in the left lower lobe bronchus. A transbronchial lung biopsy showed alveolar hemorrhage. A traumatic pulmonary pseudocyst was diagnosed from his trauma history and these findings. Computed tomography of the chest performed 4 months later showed regression of the cavitary lesion.

• Journal of Trauma and Injury
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• v.34 no.4
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• pp.299-304
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• 2021

Atypical hemolytic uremic syndrome (aHUS) is a rare, progressive, life-threatening condition of thrombotic microangiopathy characterized by thrombocytopenia, microangiopathic hemolytic anemia, and renal impairment. The mechanisms underlying aHUS remain unclear. Herein, we present the first case in the literature of aHUS after a traumatic injury. A 55-year-old male visited the emergency department after a traumatic injury caused by a tree limb. Abdominal computed tomography revealed a rectal wall defect with significant air density in the perirectal space and preperitoneum, implying rectal perforation. Due to the absence of intraperitoneal intestinal perforation, we performed diverting sigmoid loop colostomy. An additional intermittent simple repair was performed due to perianal and anal injuries. One day postoperatively, his urine output abruptly decreased and serum creatinine level increased. His platelet level decreased, and a spiking fever occurred after 2 days. The patient was diagnosed with acute renal failure secondary to aHUS and was treated with fresh frozen plasma replacement. Continuous renal replacement therapy (CRRT) was also started for oliguria and uremic symptoms. The patient received CRRT for 3 days and intermittent hemodialysis thereafter. After hemodialysis and subsequent supportive treatment, his urine output and renal function improved. The hemolytic anemia and thrombocytopenia also gradually improved. Dialysis was terminated on day 22 of admission and the patient was discharged after recovery. This case suggests that that a traumatic event can trigger aHUS, which should be considered in patients who have thrombocytopenia and acute renal failure with microangiopathic hemolytic anemia. Early diagnosis and appropriate management are critical for favorable outcomes.

• Journal of the Korea Computer Graphics Society
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• v.23 no.1
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• pp.49-55
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• 2017

Computed tomographic angiography (CTA) is widely used in the diagnosis and treatment of coronary artery disease because it shows not only the whole anatomical structure of the cardiovascular three-dimensionally but also provides information on the lesion and type of plaque. However, due to the large size of the image, there is a limitation in manually extracting coronary arteries, and related researches are performed to automatically extract coronary arteries accurately. As the coronary artery originate from the ascending aorta, the ascending aorta and ostium should be detected to extract the coronary tree accurately. In this paper, we propose an automatic segmentation for the ostium as a starting structure of coronary artery in CTA. First, the region of the ascending aorta is initially detected by using Hough circle transform based on the relative position and size of the ascending aorta. Second, the volume of interest is defined to reduce the search range based on the initial area. Third, the refined ascending aorta is segmented by using a two-dimensional geodesic active contour. Finally, the two ostia are detected within the region of the refined ascending aorta. For the evaluation of our method, we measured the Euclidean distance between the result and the ground truths annotated manually by medical experts in 20 CTA images. The experimental results showed that the ostia were accurately detected.

• Clinical and Experimental Pediatrics
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• v.51 no.6
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• pp.660-664
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• 2008

The term tracheal bronchus refers to an abnormal bronchus that comes directly off of the lateral wall of the trachea (above the carina) and supplies ventilation to the upper lobe. Tracheal bronchi occur almost exclusively on the right trachea and are associated with other congenital anomalies. In addition, tracheai bronchus may be related to other inflammatory conditions with persistent wheezing, such as recurrent pneumonia, chronic bronchitis and bronchiectasis, which is a result of the relatively poor local drainage of the involved bronchi. An infant with recurrent wheezing is likely to be a challenge for a clinician in the evaluation of the etiology of airway obstruction and in the differential diagnosis of wheezy breathing. The authors report a case of an 8-month-old female infant with a ventricular septal defect, who presented with stridor and recurrent respiratory infection and finally was finally diagnosed with a tracheal bronchus using computed tomography and a bronchoscopy. Therefore, tracheal bronchus should be included in the differential diagnosis of any child who presents with chronic or recurrent respiratory tract symptoms such as coughing, wheezing, stridor and recurrent respiratory infection, particularly in children with other congenital deformities.