• Korean Journal of Radiology
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• 제23권3호
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• pp.343-354
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• 2022

Objective: To develop and evaluate a deep learning-based artificial intelligence (AI) model for detecting skull fractures on plain radiographs in children. Materials and Methods: This retrospective multi-center study consisted of a development dataset acquired from two hospitals (n = 149 and 264) and an external test set (n = 95) from a third hospital. Datasets included children with head trauma who underwent both skull radiography and cranial computed tomography (CT). The development dataset was split into training, tuning, and internal test sets in a ratio of 7:1:2. The reference standard for skull fracture was cranial CT. Two radiology residents, a pediatric radiologist, and two emergency physicians participated in a two-session observer study on an external test set with and without AI assistance. We obtained the area under the receiver operating characteristic curve (AUROC), sensitivity, and specificity along with their 95% confidence intervals (CIs). Results: The AI model showed an AUROC of 0.922 (95% CI, 0.842-0.969) in the internal test set and 0.870 (95% CI, 0.785-0.930) in the external test set. The model had a sensitivity of 81.1% (95% CI, 64.8%-92.0%) and specificity of 91.3% (95% CI, 79.2%-97.6%) for the internal test set and 78.9% (95% CI, 54.4%-93.9%) and 88.2% (95% CI, 78.7%-94.4%), respectively, for the external test set. With the model's assistance, significant AUROC improvement was observed in radiology residents (pooled results) and emergency physicians (pooled results) with the difference from reading without AI assistance of 0.094 (95% CI, 0.020-0.168; p = 0.012) and 0.069 (95% CI, 0.002-0.136; p = 0.043), respectively, but not in the pediatric radiologist with the difference of 0.008 (95% CI, -0.074-0.090; p = 0.850). Conclusion: A deep learning-based AI model improved the performance of inexperienced radiologists and emergency physicians in diagnosing pediatric skull fractures on plain radiographs.

• Korean Journal of Radiology
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• 제23권3호
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• pp.370-380
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• 2022

Objective: To compare pneumonic-type invasive mucinous adenocarcinoma (pIMA) confined to a single lobe with clinical T2, T3, and T4 stage lung cancer without pathological node metastasis regarding survival after curative surgery and to identify prognostic factors for pIMA. Materials and Methods: From January 2010 to December 2017, 41 patients (15 male; mean age ± standard deviation, 66.0 ± 9.9 years) who had pIMA confined to a single lobe on computed tomography (CT) and underwent curative surgery were identified in two tertiary hospitals. Three hundred and thirteen patients (222 male; 66.3 ± 9.4 years) who had non-small cell lung cancer (NSCLC) without pathological node metastasis and underwent curative surgery in one participating institution formed a reference group. Relapse-free survival (RFS) and overall survival (OS) were calculated using the Kaplan-Meier method. Cox proportional hazard regression analysis was performed to identify factors associated with the survival of patients with pIMA. Results: The 5-year RFS and OS rates in patients with pIMA were 33.1% and 56.0%, respectively, compared with 74.3% and 91%, 64.3% and 71.8%, and 46.9% and 49.5% for patients with clinical stage T2, T3, and T4 NSCLC in the reference group, respectively. The RFS of patients with pIMA was comparable to that of patients with clinical stage T4 NSCLC and significantly worse than that of patients with clinical stage T3 NSCLC (p = 0.012). The differences in OS between patients with pIMA and those with clinical stage T3 or T4 NSCLC were not significant (p = 0.11 and p = 0.37, respectively). In patients with pIMA, the presence of separate nodules was a significant factor associated with poor RFS and OS {unadjusted hazard ratio (HR), 4.66 (95% confidence interval [CI], 1.95-11.11), p < 0.001 for RFS; adjusted HR, 4.53 (95% CI, 1.59-12.89), p = 0.005 for OS}. Conclusion: The RFS of patients with pIMA was comparable to that of patients with clinical stage T4 lung cancer. Separate nodules on CT were associated with poor RFS and OS in patients with pIMA.

• Korean Journal of Radiology
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• 제23권4호
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• pp.413-425
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• 2022

Objective: We compared appendiceal visualization on 2-mSv CT vs. conventional-dose CT (median 7 mSv) in adolescents and young adults and analyzed the undesirable clinical and diagnostic outcomes that followed appendiceal nonvisualization. Materials and Methods: A total of 3074 patients aged 15-44 years (mean ± standard deviation, 28 ± 9 years; 1672 female) from 20 hospitals were randomized to the 2-mSv CT or conventional-dose CT group (1535 vs. 1539) from December 2013 through August 2016. A total of 161 radiologists from 20 institutions prospectively rated appendiceal visualization (grade 0, not identified; grade 1, unsure or partly visualized; and grade 2, clearly and entirely visualized) and the presence of appendicitis in these patients. The final diagnosis was based on CT imaging and surgical, pathologic, and clinical findings. We analyzed undesirable clinical or diagnostic outcomes, such as negative appendectomy, perforated appendicitis, more extensive than simple appendectomy, delay in patient management, or incorrect CT diagnosis, which followed appendiceal nonvisualization (defined as grade 0 or 1) and compared the outcomes between the two groups. Results: In the 2-mSv CT and conventional-dose CT groups, appendiceal visualization was rated as grade 0 in 41 (2.7%) and 18 (1.2%) patients, respectively; grade 1 in 181 (11.8%) and 81 (5.3%) patients, respectively; and grade 2 in 1304 (85.0%) and 1421 (92.3%) patients, respectively (p < 0.001). Overall, undesirable outcomes were rare in both groups. Compared to the conventional-dose CT group, the 2-mSv CT group had slightly higher rates of perforated appendicitis (1.1% [17] vs. 0.5% [7], p = 0.06) and false-negative diagnoses (0.4% [6] vs. 0.0% [0], p = 0.01) following appendiceal nonvisualization. Otherwise, these two groups were comparable. Conclusion: The use of 2-mSv CT instead of conventional-dose CT impairs appendiceal visualization in more patients. However, appendiceal nonvisualization on 2-mSv CT rarely leads to undesirable clinical or diagnostic outcomes.

• Korean Journal of Radiology
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• 제23권3호
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• pp.322-332
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• 2022

Objective: CT plays a central role in determining the resectability of pancreatic cancer, which directs the use of neoadjuvant therapy. This study aimed to assess the diagnostic accuracy of CT in predicting circumferential resection margin (CRM) involvement in patients with resectable or borderline resectable pancreatic head cancer. Materials and Methods: Seventy-seven patients who were scheduled for upfront surgery for resectable or borderline resectable pancreatic head cancer were prospectively enrolled, and 75 patients (38 male and 37 female; mean age ± standard deviation, 68 ± 11 years) were finally analyzed. The CRM status was evaluated separately for the superior mesenteric artery (SMA) and posterior and superior mesenteric vein/portal vein (SMV/PV) margins. Three independent radiologists reviewed the preoperative CT images and evaluated the resection margin status. The reference standard for CRM status was pathologic examination of pancreaticoduodenectomy specimens in an axial plane perpendicular to the axis of the second portion of the duodenum. The diagnostic accuracy of CT was assessed for overall CRM involvement, defined as involvement of the SMA or posterior margins (per-patient analysis), and involvement of each of the three resection margins (per-margin analysis). The data were pooled using a crossed random effects model. Results: Forty patients had pathologically confirmed overall CRM involvement in pancreatic cancer, while CRM involvement was not seen in 35 patients. For overall CRM involvement, the pooled sensitivity and specificity were 15% (95% confidence interval: 7%-49%) and 99% (96%-100%), respectively. For each of the resection margins, the pooled sensitivity and specificity were 14% (9%-54%) and 99% (38%-100%) for the SMA margin, 12% (8%-46%) and 99% (97%-100%) for the posterior margin; and 37% (29%-53%) and 96% (31%-100%) for the SMV/PV margin, respectively. Conclusion: CT showed very high specificity but low sensitivity in predicting pathological CRM involvement in pancreatic cancer.

• 대한영상의학회지
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• 제81권6호
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• pp.1523-1528
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• 2020

부분 폐정맥 환류 이상은 드문 선천성 폐정맥 기형의 한 종류로 진단 시 종종 간과될 수 있다. 대부분의 경우 비 침습적인 영상검사인 심장 초음파, CT 또는 MRI로 진단을 하게 되는데, 2D 모니터를 이용한 영상진단은 삼차원적으로 복잡한 심장의 구조를 이해하는데 제한이 있다. 최근에는 CT와 MRI에서 얻은 의료 영상 데이터를 기반으로 3D 프린팅 기술을 이용하여 심장의 모형을 만드는 기술이 소개되어 점차 이용이 증가되고 있다. 본 증례 보고에서 저자들은 우측 상 폐정맥과 우측 중 폐정맥이 상대정맥으로의 각각 배출되며 우측 중 폐정맥을 통해 양측 심방 간의 연결이 이루어진 환자의 CT 영상 및 3D 프린팅 모델에 대해 보고하고자 한다.

• Journal of Chest Surgery
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• 제57권1호
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• pp.44-52
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• 2024

Background: Visceral pleural invasion (VPI) is a poor prognostic factor that contributes to the upstaging of early lung cancers. However, the preoperative assessment of VPI presents challenges. This study was conducted to examine intraoperative pleural carcinoembryonic antigen (pCEA) level and maximum standardized uptake value (SUVmax) as predictive markers of VPI in patients with clinical T1N0M0 lung adenocarcinoma. Methods: A retrospective review was conducted of the medical records of 613 patients who underwent intraoperative pCEA sampling and lung resection for non-small cell lung cancer. Of these, 390 individuals with clinical stage I adenocarcinoma and tumors ≤30 mm were included. Based on computed tomography findings, these patients were divided into pleural contact (n=186) and non-pleural contact (n=204) groups. A receiver operating characteristic (ROC) curve was constructed to analyze the association between pCEA and SUVmax in relation to VPI. Additionally, logistic regression analysis was performed to evaluate risk factors for VPI in each group. Results: ROC curve analysis revealed that pCEA level greater than 2.565 ng/mL (area under the curve [AUC]=0.751) and SUVmax above 4.25 (AUC=0.801) were highly predictive of VPI in patients exhibiting pleural contact. Based on multivariable analysis, pCEA (odds ratio [OR], 3.00; 95% confidence interval [CI], 1.14-7.87; p=0.026) and SUVmax (OR, 5.25; 95% CI, 1.90-14.50; p=0.001) were significant risk factors for VPI in the pleural contact group. Conclusion: In patients with clinical stage I lung adenocarcinoma exhibiting pleural contact, pCEA and SUVmax are potential predictive indicators of VPI. These markers may be helpful in planning for lung cancer surgery.

• 대한방사선치료학회지
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• 제35권
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• pp.33-39
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• 2023

목 적: 환자 체표면과 고정기구 사이에 발생하는 공기층 두께에 따른 선량 변화를 치료 계획을 통해 알아보고자 한다. 대상 및 방법: 팬텀과 열가소성 고정기구 사이에 5 mm 두께의 Bolus를 0, 1, 2, 3장을 놓아 공기층의 두께를 조절하였고 고정기구를 씌워 총 4가지 조건으로 전산화 모의단층촬영을 시행하였다. 430 cGy (Relative Biological Effectiveness,RBE)씩 6번이 조사 되도록 계획하였으며, 임상표적체적의 95% 부피에 전달된 선량이 2580 cGy (RBE)가 되도록 치료 계획을 수립하였다. 임상표적체적의 선량은 Lateral dose profile의 반치폭값으로 평가하였고 피부 선량은 선량 체적 곡선으로 평가하였다. 결 과: 임상표적체적에서 Lateral dose profile 반치폭 값은 4.89, 4.86, 5.10, 5.10 cm로 나타났다. 피부에서 4가지 조건의 선량의 평균값은 D_95%3.25±1.7 cGy (RBE), D_30%1193.5±10.2 cGy (RBE)의 차이를 보였으며 처방 선량 1%에서의 피부 부피 값 평균은 83.22±4.8% 이내의 차이를 확인하였다. 공기층 두께 변화에 따른 임상표적체적과 피부에서의 선량 모두 큰 변화를 보이지는 않았다. 결론 : 탄소입자 치료를 위해 Solid 형태의 고정기구 제작 시 약간의 공기층은 CTV의 선량 적용 범위를 벗어나지 않는다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제50권1호
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• pp.13-26
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• 2024

Objectives: The aim of this study was to perform a comparative analysis of the ultrastructural and chemical composition of sialoliths, tonsilloliths, and antroliths and to describe their growth pattern. Materials and Methods: We obtained 19 specimens from 18 patients and classified the specimens into three groups: sialolith (A), tonsillolith (B), and antrolith (C). The peripheral, middle, and core regions of the specimens were examined in detail by histology, micro-computed tomography (micro-CT), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy, and transmission electron microscopy (TEM). Results: In the micro-CT, group A showed alternating radiodense and radiolucent layers, while group B had a homogeneous structure. Group C specimens revealed a compact homogeneous structure. Histopathologically, group A showed a laminated, teardrop-shaped, globular structure. Group B demonstrated degrees of immature calcification of organic and inorganic materials. In group C, the lesion was not encapsulated and showed a homogeneous lamellar bone structure. SEM revealed that group A showed distinct three layers: a peripheral multilayer zone, intermediate compact zone, and the central nidus area; groups B and C did not show these layers. The main elemental components of sialoliths were O, C, Ca, N, Cu, P, Zn, Si, Zr, F, Na, and Mg. In group B, a small amount of Fe was found in the peripheral region. Group C had a shorter component list: Ca, C, O, P, F, N, Si, Na, and Mg. TEM analysis of group A showed globular structures undergoing intra-vesicular calcification. In group B, bacteria were present in the middle layer. In the outer layer of the group C antrolith, an osteoblastic rimming was observed. Conclusion: Sialoliths had distinct three layers: a peripheral multilayer zone, an intermediate compact zone and the central nidus area, while the tonsillolith and antrolith specimens lacked distinct layers and a core.

• 대한영상의학회지
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• 제84권4호
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• pp.891-899
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• 2023

목적 급성호흡기질환인 코로나바이러스감염증-19 (coronavirus disease 2019; 이하 COVID-19) 환자를 대상으로 한 음압격리들것(negative presurre isolation stretcher; 이하 NPIS)을 이용한 흉부 전산화단층촬영(이하 CT) 방식에 대해 전문의들의 경험과 의견을 확인하고자 하였다. 대상과 방법 격리입원 중인 COVID-19 환자에게 NPIS를 이용한 흉부 CT 검사를 시행했던 9개 의료기관 소속 27명의 전문의들을 대상으로 1) 조영증강 흉부 CT가 필요한 경우, 2) NPIS를 이용한 흉부 CT의 영상품질, 그리고 3) CT 조영제주사를 위한 NPIS 개방과 CT 검사실의 오염을 주제로 설문조사를 진행하였다 결과 조사대상인 9개의 의료기관들은 기관당 한 해 평균 116건의 COVID-19관련 흉부 CT 검사를 NPIS와 함께 진행했으며. 전체 검사 건수 중 평균 24건(21%)이 조영증강 흉부 CT였다. 설문에 참여한 호흡기내과 전문의 9명 중 5명(56%)은 환자의 혈중 D-dimer 이상이 확인되면 조영증강 CT가 필요하다고 의견을 밝혔다. 한편 영상의학과 전문의 9명 모두는 NPIS로 인한 흉부 CT 영상의 품질은 폐렴 또는 폐혈전 진단이 가능한 수준이라 답하였다. 또한 감염내과 전문의 9명 중 5명(56%)은 NPIS의 개방으로 인한 CT 검사실의 이차감염은 소독을 통해 예방할 수 있는 수준으로 생각하고 있었다. 결론 격리입원 중인 COVID-19 환자에서 NPIS와 함께 흉부 CT를 진행하더라도 CT의 품질은 진단이 가능한 수준이며 NPIS가 CT 검사실 내에서 잠시 개방되더라도 CT 검사실의 감염확산 위험은 높지 않은 것으로 전문의들은 인식하고 있었다.

• 대한영상의학회지
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• 제84권4호
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• pp.911-922
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• 2023

목적 전산화단층촬영 소장조영술 준비를 위해서 사용된 중성 경구 조영제인 희석된 폴리에틸렌 글리콜 용액과 저밀도(0.1% w/v) 바륨 현탁액 사이의 소장 팽창과 부작용을 비교하였다. 대상과 방법 전산화단층촬영 소장조영술을 시행 받은 총 173명의 환자가 연구에 포함되었다. 50명의 환자는 바륨 현탁액을, 123명의 환자는 희석된 등삼투압의 폴리에틸렌 글리콜 용액을 사용하였다. 동일한 양인 1L를 투여하였다. 두 명의 독립된 검토자가 공장과 회장에서 5점 척도로 소장 팽창을 평가하였다. 두 그룹 간의 부작용 비교를 위해서 경구 조영제 투입 후 환자들이 구역, 구토, 설사 및 복통을 호소하는지 여부에 대하여 조사하였다. 결과 회장과 공장에서, 희석된 폴리에틸렌 글리콜 용액은 두 검토자 모두에서 바륨 현탁액과 차이가 없었다(회장: 검토자 1, 중앙값, 4; 4, 사분위수 범위, 3-4; 3-4, p = 0.997; 검토자 2, 중앙값, 4; 4, 사분위수 범위, 3.3-4.0; 3-4, p = 0.064, 공장: 검토자 1, 중앙값, 2; 2, 사분위수 범위, 2-3; 2-3, p = 0.560; 검토자 2, 중앙값, 3; 2, 사분위수 범위, 2-3; 2-3, p = 0.192). 모든 환자에서 두 가지 경구 조영제 투여 후 즉각적인 부작용을 호소하지 않았다. 결론 희석된 폴리에틸렌 글리콜 용액은 바륨 현탁액과 비교하여 소장 팽창에 차이가 없고, 검사 직후 부작용이 없으므로, 유용한 대체제가 될 수 있다.