• Journal of Korean Neurosurgical Society
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• 제67권1호
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• pp.115-121
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• 2024

After treatment of unilateral vertebral artery dissecting aneurysm (VADA), de novo VADA rarely occurs on the contralateral side. In this article, we report a case of subarachnoid hemorrhage (SAH) due to de novo VADA in the contralateral vertebral artery (VA) 3 years after parent artery occlusion of unilateral VADA, with a review of the literature. A 47-year-old woman was admitted to our hospital complaining of headache and impaired consciousness. Head computed tomography showed SAH, and three-dimensional computed tomography angiography showed a fusiform aneurysm in the left VA. We performed an emergency parent artery occlusion. Three years and 3 months after the initial treatment, the patient presented to our hospital with complaints of headache and neck pain. Magnetic resonance imaging revealed SAH, and magnetic resonance angiography revealed de novo VADA in the right VA. We performed a stent-assisted coil embolization. The patient had a good postoperative course and was discharged with a modified Rankin scale score of 0. Long-term follow-up is necessary in patients with VADA because contralateral de novo VADA can develop even several years after the initial treatment.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제37권1호
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• pp.36-42
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• 2011

Introduction: The current study examined the morphological characteristics of maxillary sinus septum by computed tomography (CT). Materials and Methods: Two hundred and four patients (408 maxillary sinuses) who visited dental clinic were evaluated. CT were examined. The height of the septum measured from the sinus floor to the apex of the septum more than 3 mm was defined as "sinus septum". Results: The prevalence of sinus septa was 21.3% (87/408), and 31.4% (64/204) of patients had more than 1 sinus septum. Females showed higher and thinner sinus septa than males. The anatomic location of the septa were distributed in the 2nd molar region (43.7%), 1st molar region (31.0%), 2nd premolar region (21.8%) and 1st premolar region (3.5%). In 57 patients with chronic disease, there was no significant difference between sinus disease and the presence of sinus septa. The loss of remaining teeth and teeth adjacent to the sinus septum area was not related to the presence of sinus septa. Older subjects showed a reduced height and length of the septum, and a thicker septum. Conclusion: These results show that the maxillary sinus septum undergoes atrophy with age.

• Imaging Science in Dentistry
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• 제47권3호
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• pp.199-207
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• 2017

Purpose: Evaluation of alveolar bone is important in the diagnosis of dental diseases. The periodontal ligament space is difficult to clearly depict in cone-beam computed tomography images because the reconstruction filter conditions during image processing cause image blurring, resulting in decreased spatial resolution. We examined different reconstruction filters to assess their ability to improve spatial resolution and allow for a clearer visualization of the periodontal ligament space. Materials and Methods: Cone-beam computed tomography projections of 2 skull phantoms were reconstructed using 6 reconstruction conditions and then compared using the Thurstone paired comparison method. Physical evaluations, including the modulation transfer function and the Wiener spectrum, as well as an assessment of space visibility, were undertaken using experimental phantoms. Results: Image reconstruction using a modified Shepp-Logan filter resulted in better sensory, physical, and quantitative evaluations. The reconstruction conditions substantially improved the spatial resolution and visualization of the periodontal ligament space. The difference in sensitivity was obtained by altering the reconstruction filter. Conclusion: Modifying the characteristics of a reconstruction filter can generate significant improvement in assessments of the periodontal ligament space. A high-frequency enhancement filter improves the visualization of thin structures and will be useful when accurate assessment of the periodontal ligament space is necessary.

• Imaging Science in Dentistry
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• 제53권1호
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• pp.43-51
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• 2023

Purpose: This study aimed to assess texture analysis(TA) of cone-beam computed tomography (CBCT) images as a quantitative tool for the differential diagnosis of odontogenic and non-odontogenic maxillary sinusitis(OS and NOS, respectively). Materials and Methods: CBCT images of 40 patients diagnosed with OS (N=20) and NOS (N=20) were evaluated. The gray level co-occurrence (GLCM) matrix parameters, and gray level run length matrix texture (GLRLM) parameters were extracted using manually placed regions of interest on lesion images. Seven texture parameters were calculated using GLCM and 4 parameters using GLRLM. The Mann-Whitney test was used for comparisons between the groups, and the Levene test was performed to confirm the homogeneity of variance (α=5%). Results: The results showed statistically significant differences(P<0.05) between the OS and NOS patients regarding 3 TA parameters. NOS patients presented higher values for contrast, while OS patients presented higher values for correlation and inverse difference moment. Greater textural homogeneity was observed in the OS patients than in the NOS patients, with statistically significant differences in standard deviations between the groups for correlation, sum of squares, sum of entropy, and entropy. Conclusion: TA enabled quantitative differentiation between OS and NOS on CBCT images by using the parameters of contrast, correlation, and inverse difference moment.

• Imaging Science in Dentistry
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• 제53권2호
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• pp.109-115
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• 2023

Purpose: The aim of this study was to evaluate changes in the trabecular bone through texture analysis and compare the texture analysis characteristics of different areas in patients with medication-related osteonecrosis of the jaw (MRONJ). Materials and Methods: Cone-beam computed tomographic images of 16 patients diagnosed with MRONJ were used. In sagittal images, 3 regions were chosen: active osteonecrosis(AO); intermediate tissue (IT), which presented a zone of apparently healthy tissue adjacent to the AO area; and healthy bone tissue (HT) (control area). Texture analysis was performed evaluating 7 parameters: secondary angular momentum, contrast, correlation, sum of squares, inverse moment of difference, sum of entropies, and entropy. Data were analyzed using the Kruskal-Wallis test with a significance level of 5%. Results: Comparing the areas of AO, IT, and HT, significant differences (P<0.05) were observed. The IT and AO area images showed higher values for parameters such as contrast, entropy, and secondary angular momentum than the HT area, indicating greater disorder in these tissues. Conclusion: Through texture analysis, changes in the bone pattern could be observed in areas of osteonecrosis. The texture analysis demonstrated that areas visually identified and classified as IT still had necrotic tissue, thereby increasing the accuracy of delimiting the real extension of MRONJ.

• 대한족부족관절학회지
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• 제21권4호
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• pp.144-150
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• 2017

Purpose: To assess the clinical and radiographic results and complications of arthroscopy-assisted reduction and percutaneous fixation for patients with tongue-type Sanders type II calcaneal fractures. Materials and Methods: Between August 2014 and December 2015, 10 patients who underwent surgery using subtalar arthroscopic assisted reduction and percutaneous fixation for tongue-type Sanders type II calcaneal fractures were reviewed. The mean age was 50.8 years (36~62 years), and the mean follow-up period was 24 months (12~40 months). The clinical results were evaluated using the visual analogue scale (VAS) and American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score at the regular follow-ups, and the foot function index (FFI) at the last follow-up. The subtalar range of motion (ROM) was evaluated and compared with the uninjured limb at the last follow-up. The radiographic results were assessed using the Bohler's angle from the plain radiographs and the reduction of the posterior calcaneal facet using computed tomography (CT). The postoperative complications were assessed by a chart review. Results: The VAS and AOFAS ankle-hindfoot score improved until 12 months after surgery. The FFI was 15 (1.8~25.9) and subtalar ROM was 75.5% (60%~100%) compared to the uninjured limb at the last follow-up. The $B{\ddot{o}}hler^{\prime}s$ angle was increased significantly from $2^{\circ}$ ($-14^{\circ}{\sim}18^{\circ}$) preoperatively to $21.8^{\circ}$ ($20^{\circ}{\sim}28^{\circ}$) at the last follow-up. The reduction of the posterior facet was graded as excellent in five feet (50.0%) and good in five (50.0%) on CT obtained at 12 months after surgery. One foot (10.0%) had subfibular pain due to a prominent screw head. One foot (10.0%) had pain due to a longitudinal tear of the peroneal tendon that occurred during screw insertion. Conclusion: Subtalar arthroscopic-assisted reduction of the posterior calcaneal facet of the subtalar joint and percutaneous fixation is a useful surgical method for tongue-type Sanders type II calcaneal fractures.

• Journal of Korean Neurosurgical Society
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• 제65권6호
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• pp.801-815
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• 2022

Objective : To evaluate the stent apposition of a low-profile visualized intraluminal support (LVIS) device in distal internal carotid artery (ICA) aneurysms, examine its correlation with clinical and angiographic outcomes, and determine the predictive factors of ischemic adverse events (IAEs) related to stent-assisted coiling. Methods : We retrospectively analyzed a prospectively maintained database of 183 patients between January 2017 and February 2020. The carotid siphon from the cavernous ICA to the ICA terminus was divided into posterior, anterior, and superior bends. The anterior bends were categorized into angled (V) and non-angled (C, U, and S) types depending on the morphology and measured angles. Complete stent apposition (CSA) and incomplete stent apposition (ISA) were evaluated using unsubtracted angiography and flat-panel detector computed tomography. Dual antiplatelet therapy with aspirin 200 mg and clopidogrel 75 mg was administered. Clopidogrel resistance was defined as fewer responders (≥10%, <40%) and non-responders (<10%) based on the percent inhibition (%INH) of the VerifyNow system. These were counteracted by a dose escalation to 150 mg for fewer responders or substitution with cilostazol 200 mg for non-responders. IAEs included intraoperative in-stent thrombosis, transient ischemic attack, cerebral infarction, and delayed in-stent stenosis. A multivariate logistic regression analysis was used to determine the predictive factors for ISA and IAEs. Results : There were 33 ISAs (18.0%) and 27 IAEs (14.8%). The anterior bend angle was narrower in ISA (-4.16°±25.18°) than in CSA (23.52°±23.13°) (p<0.001). The V- and S-types were independently correlated with the ISA (p<0.001). However, treatment outcomes, including IAEs (15.3% vs. 12.1%), aneurysmal complete occlusion (91.3% vs. 88.6%), and recanalization (none of them), did not differ between CSA and ISA (p>0.05). The %INH of 27 IAEs (13.78%±14.78%) was significantly lower than that of 156 non-IAEs (26.82%±20.23%) (p<0.001). Non-responders to clopidogrel were the only significant predictive factor for IAEs (p=0.001). Conclusion : The angled and tortuous anatomical peculiarity of the carotid siphon caused ISA of the LVIS device; however, it did not affect clinical and angiographic outcomes, while the non-responders to clopidogrel affected the IAEs related to stent-assisted coiling.

• Journal of Chest Surgery
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• 제50권6호
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• pp.456-459
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• 2017

A 66-year-old patient undergoing regular follow-up at Samsung Medical Center after left lower lobectomy visited the emergency department around 9 months postoperatively because of nausea and vomiting after routine esophagogastroduodenoscopy at a local clinic. Abdominal computed tomography showed the stomach herniating into the left thoracic cavity. We explored the pleural cavity via video-assisted thoracic surgery (VATS). Adhesiolysis around the herniated stomach and laparotomic reduction under video assistance were successfully performed. The diaphragmatic defect was repaired via VATS. The postoperative course was uneventful, and he was discharged with resolved digestive tract symptoms.

• Journal of Gastric Cancer
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• 제13권3호
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• pp.185-187
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• 2013

Neurofibromas are benign tumors that originate from the peripheral nerves, including neurites and fibroblasts. Generally, a solitary neurofibroma is located in the skin and rarely in other places. A 72-year-old female suffered from epigastric discomfort for 2 months. Endoscopic findings showed an early gastric cancer type IIc at the antrum. Abdominal computed tomography revealed early gastric cancer with a 1.6 cm-sized metastatic node posterior to the duodenum. Laparoscopic assisted distal gastrectomy and retro-pancreatic dissection were performed uneventfully. Histological examination revealed gastric adenocarcinoma, invading the mucosa without nodal metastasis, and a neurofibroma. Herein, we present a case of a gastric cancer patient with a solitary retroperitoneal neurofibroma which mimicked a distant metastatic node.

• Journal of Chest Surgery
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• 제49권4호
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• pp.302-305
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• 2016

A 16-year-old girl was transferred to the department of thoracic and cardiovascular surgery because of a spontaneous pneumothorax with prolonged air leakage. Chest computed tomography demonstrated a cystic lesion measuring $2{\times}3cm$ and involving the left upper lobe. Left upper lobectomy was performed via video-assisted thoracoscopic surgery. A pathologic examination of the specimen revealed a mesenchymal cystic hamartoma. Despite the rarity of pulmonary mesenchymal cystic hamartoma, it should be considered a potential cause of pneumothorax for patients with a large pulmonary cyst. Further, surgical resection must be considered because serious complications such as hemothorax, hemoptysis, and malignant transformation have been reported.