• Korean Journal of Radiology
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• 제24권12호
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• pp.1284-1292
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• 2023

Objective: We investigated the impacts of computed tomography (CT) added to ultrasound (US) for preoperative evaluation of patients with papillary thyroid carcinoma (PTC) on staging, surgical extent, and postsurgical survival. Materials and Methods: Consecutive patients who underwent surgery for PTC between January 2015 and December 2015 were retrospectively identified. Of them, 584 had undergone preoperative additional thyroid CT imaging (CT + US group), and 859 had not (US group). Inverse probability of treatment weighting (IPTW) and propensity score matching (PSM) were used to adjust for 14 variables and balance the two groups. Changes in nodal staging and surgical extent caused by CT were recorded. The recurrence-free survival and distant metastasis-free survival after surgery were compared between the two groups. Results: In the CT + US group, discordant nodal staging results between CT and US were observed in 94 of 584 patients (16.1%). Of them, CT accurately diagnosed nodal staging in 54 patients (57.4%), while the US provided incorrect nodal staging. Ten patients (1.7%) had a change in the extent of surgery based on CT findings. Postsurgical recurrence developed in 3.6% (31 of 859) of the CT + US group and 2.9% (17 of 584) of the US group during the median follow-up of 59 months. After adjustment using IPTW (580 vs. 861 patients), the CT + US group showed significantly higher recurrence-free survival rates than the US group (hazard ratio [HR], 0.52 [95% confidence interval {CI}, 0.29-0.96]; P = 0.037). PSM analysis (535 patients in each group) showed similar HR without statistical significance (HR, 0.60 [95% CI, 0.31-1.17]; P = 0.134). For distant metastasis-free survival, HRs after IPTW and PSM were 0.75 (95% CI, 0.17-3.36; P = 0.71) and 0.87 (95% CI, 0.20-3.80; P = 0.851), respectively. Conclusion: The addition of CT imaging for preoperative evaluation changed nodal staging and surgical extent and might improve recurrence-free survival in patients with PTC.

• Korean Journal of Radiology
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• 제23권11호
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• pp.1078-1088
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• 2022

Objective: To develop and validate a model using radiomics features from apparent diffusion coefficient (ADC) map to diagnose local tumor recurrence in head and neck squamous cell carcinoma (HNSCC). Materials and Methods: This retrospective study included 285 patients (mean age ± standard deviation, 62 ± 12 years; 220 male, 77.2%), including 215 for training (n = 161) and internal validation (n = 54) and 70 others for external validation, with newly developed contrast-enhancing lesions at the primary cancer site on the surveillance MRI following definitive treatment of HNSCC between January 2014 and October 2019. Of the 215 and 70 patients, 127 and 34, respectively, had local tumor recurrence. Radiomics models using radiomics scores were created separately for T2-weighted imaging (T2WI), contrast-enhanced T1-weighted imaging (CE-T1WI), and ADC maps using non-zero coefficients from the least absolute shrinkage and selection operator in the training set. Receiver operating characteristic (ROC) analysis was used to evaluate the diagnostic performance of each radiomics score and known clinical parameter (age, sex, and clinical stage) in the internal and external validation sets. Results: Five radiomics features from T2WI, six from CE-T1WI, and nine from ADC maps were selected and used to develop the respective radiomics models. The area under ROC curve (AUROC) of ADC radiomics score was 0.76 (95% confidence interval [CI], 0.62-0.89) and 0.77 (95% CI, 0.65-0.88) in the internal and external validation sets, respectively. These were significantly higher than the AUROC values of T2WI (0.53 [95% CI, 0.40-0.67], p = 0.006), CE-T1WI (0.53 [95% CI, 0.40-0.67], p = 0.012), and clinical parameters (0.53 [95% CI, 0.39-0.67], p = 0.021) in the external validation set. Conclusion: The radiomics model using ADC maps exhibited higher diagnostic performance than those of the radiomics models using T2WI or CE-T1WI and clinical parameters in the diagnosis of local tumor recurrence in HNSCC following definitive treatment.

• Korean Journal of Radiology
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• 제23권11호
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• pp.1102-1111
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• 2022

Objective: To evaluate the ultrasonography (US) features for diagnosing metastasis in cervical lymph nodes (LNs) in patients with thyroid cancer and compare the US classification of risk of LN metastasis between European and Korean guidelines. Materials and Methods: From January 2014 to December 2018, US-guided fine-needle aspiration was performed on 836 LNs from 714 patients for the preoperative nodal staging of thyroid cancer. The US features of LNs were retrospectively reviewed for the following features: size, presence of hilum, margin, orientation, cystic change, punctate echogenic foci (PEF), large echogenic foci, eccentric cortical thickening, abnormal vascularity, and cortical hyperechogenicity. A multiple logistic regression analysis was performed to identify the independent US features for the diagnosis of metastatic LNs. The diagnostic performance of independent US features was subsequently evaluated. LNs were categorized according to the Korean Thyroid Imaging Reporting and Data System (K-TIRADS) and European Thyroid Association (ETA) guidelines, and the correlation between the two sets of classifications was assessed. Results: Absence of the hilum, presence of cystic changes, PEF, abnormal vascularity, and cortical hyperechogenicity were independent US features of metastatic LNs. Cystic changes, PEF, abnormal vascularity, and cortical hyperechogenicity showed high specificity (86.8%-99.6%). The absence of the hilum had the highest sensitivity yet low specificity (66.4%). When LNs were classified according to the ETA guidelines and K-TIRADS, they yielded similar categorizations of malignancy risks and were strongly correlated (Spearman coefficient, 0.9766 [95% confidence interval, 0.973-0.979]). According to the ETA guidelines, 9.8% (82/836) of LNs were classified as "not specified." Conclusion: Absence of hilum, cystic changes, PEF, abnormal vascularity, and cortical hyperechogenicity were independent US features suggestive of metastatic LNs in thyroid cancer. Both K-TIRADS and the ETA guidelines provided similar risk stratification for metastatic LNs with a high correlation; however, the ETA guidelines failed to classify 9.8% of LNs into a specific risk stratum. These results may provide a basis for revising LN classification in future guidelines.

• Korean Journal of Radiology
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• 제22권5호
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• pp.751-758
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• 2021

Objective: Preoperative differentiation between inverted papilloma (IP) and its malignant transformation to squamous cell carcinoma (IP-SCC) is critical for patient management. We aimed to determine the diagnostic accuracy of conventional imaging features and histogram parameters obtained from whole tumor apparent diffusion coefficient (ADC) values to predict IP-SCC in patients with IP, using decision tree analysis. Materials and Methods: In this retrospective study, we analyzed data generated from the records of 180 consecutive patients with histopathologically diagnosed IP or IP-SCC who underwent head and neck magnetic resonance imaging, including diffusion-weighted imaging and 62 patients were included in the study. To obtain whole tumor ADC values, the region of interest was placed to cover the entire volume of the tumor. Classification and regression tree analyses were performed to determine the most significant predictors of IP-SCC among multiple covariates. The final tree was selected by cross-validation pruning based on minimal error. Results: Of 62 patients with IP, 21 (34%) had IP-SCC. The decision tree analysis revealed that the loss of convoluted cerebriform pattern and the 20th percentile cutoff of ADC were the most significant predictors of IP-SCC. With these decision trees, the sensitivity, specificity, accuracy, and C-statistics were 86% (18 out of 21; 95% confidence interval [CI], 65-95%), 100% (41 out of 41; 95% CI, 91-100%), 95% (59 out of 61; 95% CI, 87-98%), and 0.966 (95% CI, 0.912-1.000), respectively. Conclusion: Decision tree analysis using conventional imaging features and histogram analysis of whole volume ADC could predict IP-SCC in patients with IP with high diagnostic accuracy.

• Korean Journal of Radiology
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• 제22권9호
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• pp.1579-1586
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• 2021

Objective: To evaluate the diagnostic performance of the modified Korean Thyroid Imaging Reporting and Data System (K-TIRADS), and compare it with the 2016 version of K-TIRADS using the Thyroid Imaging Network of Korea. Materials and Methods: Between June and September 2015, 5708 thyroid nodules (≥ 1.0 cm) from 5081 consecutive patients who had undergone thyroid ultrasonography at 26 institutions were retrospectively evaluated. We used a biopsy size threshold of 2 cm for K-TIRADS 3 and 1 cm for K-TIRADS 4 (modified K-TIRADS 1) or 1.5 cm for K-TIRADS 4 (modified K-TIRADS 3). The modified K-TIRADS 2 subcategorized the K-TIRADS 4 into 4A and 4B, and the cutoff sizes for the biopsies were defined as 1 cm for K-TIRADS 4B and 1.5 cm for K-TIRADS 4A. The diagnostic performance and the rate of unnecessary biopsies of the modified K-TIRADS for detecting malignancy were compared with those of the 2016 K-TIRAD, which were stratified by nodule size (with a threshold of 2 cm). Results: A total of 1111 malignant nodules and 4597 benign nodules were included. The sensitivity, specificity, and unnecessary biopsy rate of the benign nodules were 94.9%, 24.4%, and 60.9% for the 2016 K-TIRADS; 91.0%, 39.7%, and 48.6% for the modified K-TIRADS 1; 84.9%, 45.9%, and 43.5% for the modified K-TIRADS 2; and 76.1%, 50.2%, and 40.1% for the modified K-TIRADS 3. For small nodules (1-2 cm), the diagnostic sensitivity of the modified K-TIRADS decreased by 5.2-25.6% and the rate of unnecessary biopsies reduced by 19.2-32.8% compared with those of the 2016 K-TIRADS (p < 0.001). For large nodules (> 2 cm), the modified K-TIRADSs maintained a very high sensitivity for detecting malignancy (98%). Conclusion: The modified K-TIRADSs significantly reduced the rate of unnecessary biopsies for small (1-2 cm) nodules while maintaining a very high sensitivity for malignancy for large (> 2 cm) nodules.

• Korean Journal of Radiology
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• 제22권11호
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• pp.1875-1885
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• 2021

Objective: Central nervous system involvement in coronavirus disease 2019 (COVID-19) has been increasingly reported. We performed a systematic review and meta-analysis to evaluate the incidence of radiologically demonstrated neurologic complications and detailed neuroimaging findings associated with COVID-19. Materials and Methods: A systematic literature search of MEDLINE/PubMed and EMBASE databases was performed up to September 17, 2020, and studies evaluating neuroimaging findings of COVID-19 using brain CT or MRI were included. Several cohort-based outcomes, including the proportion of patients with abnormal neuroimaging findings related to COVID-19 were evaluated. The proportion of patients showing specific neuroimaging findings was also assessed. Subgroup analyses were also conducted focusing on critically ill COVID-19 patients and results from studies that used MRI as the only imaging modality. Results: A total of 1394 COVID-19 patients who underwent neuroimaging from 17 studies were included; among them, 3.4% of the patients demonstrated COVID-19-related neuroimaging findings. Olfactory bulb abnormalities were the most commonly observed (23.1%). The predominant cerebral neuroimaging finding was white matter abnormality (17.6%), followed by acute/subacute ischemic infarction (16.0%), and encephalopathy (13.0%). Significantly more critically ill patients had COVID-19-related neuroimaging findings than other patients (9.1% vs. 1.6%; p = 0.029). The type of imaging modality used did not significantly affect the proportion of COVID-19-related neuroimaging findings. Conclusion: Abnormal neuroimaging findings were occasionally observed in COVID-19 patients. Olfactory bulb abnormalities were the most commonly observed finding. Critically ill patients showed abnormal neuroimaging findings more frequently than the other patient groups. White matter abnormalities, ischemic infarctions, and encephalopathies were the common cerebral neuroimaging findings.

• 한국수자원학회논문집
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• 제57권5호
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• pp.359-369
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• 2024

한국은 6월 21일부터 9월 20일까지를 법정홍수기로 지정하여 잠재적 홍수에 대비하여왔다. 하지만 2020년 54일의 역대 최장 장마 사례와 같이 과거와 다른 기후양상으로 인한 극한 홍수로 피해를 겪고 있다. 그동안 홍수 피해 저감을 위한 연구는 매우 많았지만, 법정홍수기가 앞으로도 유효할지에 대한 연구는 시도된 적 이 없었다. 따라서 본 연구는 21세기 관측 자료를 통해 현행 법정홍수기의 타당성을 통계적으로 검토하였으며, 이를 통해 현행 법정홍수기가 강수량 증가 추세와 지역별 강수 특성의 강화를 고려하지 못하고 있음을 확인하였다. 이러한 한계점의 해결을 위해 본 연구에서는 대상 유역에 대한 7개의 새로운 홍수기 후보군을 제안하였고, 이의 타당성을 모의 운영을 통해 분석하였다. 모의 운영 시 댐 운영룰 rigid operation method를, 댐 유입량 예측에는 long short-term memory model을 적용하였다. 제안한 홍수기 각 후보는 댐의 계획방류량과 하천의 계획홍수량을 초과하느냐를 기준으로 평가하였다. 첫 번째 기준으로 평가한 결과, 본 연구에서 제안한 홍수기 적용 시 초과 빈도와 지속시간이 각각 0.068%와 0.33% 감소되었으며, 크기 또한 24.6% 감소하였다. 두 번째 평가 기준으로 평가한 결과 역시, 홍수피해 발생 구간이 기존의 4회에서 2회로 감소하였다. 본 연구 결과를 계기로 법정홍수기 재검토가 공식적으로 이루어져 새로운 양상으로 변화하고 있는 강우 양상에 적극적으로 대비하길 기대한다.

• 대한한방내과학회지
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• 제33권4호
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• pp.418-428
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• 2012

Objectives : Ojeok-san, a traditional herbal formula, has been used for the treatment of cold illness and its related symptoms such as headache, nausea and indigestion. This study was performed to compare effects of water (OJSW) and 70% ethanol extracts (OJSE) of Ojeok-san on inflammation and its related diseases atopy, asthma and obesity in vitro. Methods : We performed HPLC to investigate contents of index components of OJSW and OJSE. We investigated the effects of OJSW and OJSE with an in vitro model, using 5 cell lines, specifically RAW 264. 7, HaCaT, MC/9, BEAS-2B and 3T3-L1. Results : HPLC analysis displayed that the contents of index components were higher in OJSE than OJSW. In lipopolysaccharide (LPS)-treated RAW 264.7 macrophages, OJSE significantly inhibited productions of interleukin (IL)-6, nitrite and prostaglandin $E_2$ ($PEG_2$). In TNF-${\alpha}$/IFN-${\gamma}$-treated HaCaT keratinocytes, OJSE significantly lowered levels of macrophage-derived chemokine (MDC) as well as regulated and normal T cell expressed and secreted (RANTES). OJSE also had a protective effect on inflammatory response by decreasing RANTES secretion in TNF-${\alpha}$-stimulated BEAS-2B cells. Conclusions : We conclude that OJSE could be more appropriate to enhance the biological activities against inflammation and its related diseases, and could be applied as a bioactive material for developing the potent anti-inflammatory agents.

• 대한관절경학회지
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• 제10권1호
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• pp.70-76
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• 2006

목적: 금속 봉합 나사못을 이용한 견관절 습관성 전방 탈구 수술 후, 여러 원인에 의하여 발생한 금속 봉합 나사 못 돌출 합병증을 보고하고 발생 원인, 임상 양상 및 관절경적 치료에 대하여 알아보고자 하였다. 대상 및 방법: 견관절 습관성 전방 탈구로 봉합 나사못을 이용한 Bankart 수술을 시행 받은 후 운동시 들리는 관절내 마찰음 및 통증 또는 불안정성을 호소하며 내원하여 관절경 재수술을 시행받은 환자 5명을 대상으로 하였다. 처음 수술 이후 재수술까지의 평균 기간은 5.2개월이었다. 환자들은 관절경 재수술시 봉합 나사못의 돌출이 확인되었으며 관절경 술식을 이용하여 돌출 봉합 나사못을 제거하였다. 결과: 주 증상은 4명에서 통증을 동반한 관절내 마찰음이었으며 이 마찰음은 외전 및 외회전시 분명하게 들렸다. 1명은 통증과 함께 견관절 불안정성을 호소하였다. 견관절 운동 범위는 외회전만 약간 감소되었을 뿐 거의 정상 소견을 나타내었다. 돌출되었던 봉합 나사못의 위치는 5시 방향 1명, 4시 방향 2명, 2시 및 3시 방향 각각 1명씩이었다. 그 중 2명은 전방 관절와연에서 5 mm 정도 내측 관절면 위에 위치하였다. 나머지 3명은 올바른 위치에 삽입되어 있었으나 나사못 주변의 연골 마모 및 골소실이 관찰되었다. 재수술시 5명 모두 상완골두에 연골 손상이 발견되었으며 1명은 관절와에도 연골 결손이 동반되었다. 재수술 후 2년째 추시 결과 재탈구나 불안정성을 보이는 환자는 없었으며 통증에 대한 VAS 점수는 수술 전 3.4에서 수술 후 1.2로 감소되었다. Constant 점수는 수술 전 65점에서 수술 후 89점으로 증가하였으며 ASES 점수도 수술 전 67점에서 수술후 88점으로 증가하였다. 결론: 봉합 나사못 합병증으로 인한 증상은 불안정성을 동반하지 않는 경우가 많으며 대부분 재활 운동 시점부터 증상이 나타나지만 정상적인 수술 후 통증과 구분이 어려운 경우가 많다 그러나 돌출된 봉합 나사못은 상완골두 연골의 파괴를 유발하는 심각한 합병증을 초래하므로 봉합 나사못 돌출이 의심되면 관절경을 통하여 관절내의 변화를 관찰하며 돌출된 봉합 나사못을 다시 삽입하거나 제거하여야 한다. 봉합 나사못 제거에 본 수술 방법을 사용하면 용이하게 봉합 나사못 제거가 가능하리라 사료된다.

• Tuberculosis and Respiratory Diseases
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• 제64권1호
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• pp.15-21
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• 2008

연구배경: 기관지 내시경으로 조직 검사가 불가능한 고립성 폐결절 환자에서 경피적 폐생검이 중요한 진단 방법으로 사용되고 있으나, 기흉 및 출혈 등의 합병증 및 접근성 등이 문제가 된다. 흑색종항원유전자(Melanoma Antigen Gene, MAGE)는 악성 흑색종에서 처음 발견된 20 종양 항원 및 유전자로서, 비소세포폐암을 비롯한 다양한 암종에서 발현되며 정상 조직에서는 남성의 생식기 세포 및 태반에서만 발현된다. 본 연구는 기관지내시경으로 보이지 않았던 비소세포폐암 환자에서 기관지 세척액을 이용한 MAGE 양성 여부를 검사하여 폐암의 진단에 어느정도 도움이 되는지 알아보고자 하였다. 방법: 2007년 1월부터 2개월간 삼성서울병원 호흡기 내과에서 기관지 내시경을 시행한 환자 중에서 내시경적 조직 검사가 불가능한 고립성 폐결절 환자 37명을 대상으로 하였다. 기관지 세척을 시행하여 MAGE A1-6 RT-nested PCR (iC&G Co, Daegu, Korea)검사와 세포진 검사를 시행하였고, 경피적 폐생검 및 수술을 통한 병리학적인 진단과 비교하였다. 결과: 37명 중에서 비소세포폐암 환자는 21명(56.8%) 이었고(선암종 13/21, 편평상피세포암 8/21), 나머지 16명 (43.2%)은 폐결핵(5), 진균 감염(3), 기질화 폐렴(2) 및 유육종증, 비결핵 항산균 폐질환과 선천성 낭종 등으로 진단되었다. 비소세포폐암 환자에서 세포학적인 검사의 양성률은 9.5% (2/21)에 불과하였으나, MAGE mRNA는 47.6% (10/21)에서 양성을 보여 양성 예측률이 71.4%였다. MAGE 양성률은 편평상피세포암에서 더 높게 나타났다 (선암종 30.8%, 편평상피세포암 75.0%, p>0.05). 양성 병변으로 진단된 16명의 MAGE 발현율은 25.0% (4/16)였다. 결론: 기관지 세척액을 이용한 MAGE 검사는 기관지 내시경을 통한 조직검사가 불가능한 고립성 폐결절에서 기존의 세포진검사에 비해 우수한 양성 예측률을 나타내어 폐암의 진단에 도움이 될 것으로 보인다.