• Investigative Magnetic Resonance Imaging
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• 제13권2호
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• pp.152-160
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• 2009

목적: 대동맥궁 상부의 두개강내외 동맥의 협착을 평가함에 있어 3차원 조영증강 자기공명영상 혈관조영술(contrast-enhanced magnetic resonance angiography, CE-MRA), 전산화 단층 혈관 조영술(computed tomographic angiography, CTA),그리고 디지털 감산 혈관조영술(digital subtraction angiography)의 진단 정확도를 비교하고자 하였다. 대상 및 방법: 총 대동맥궁 상부의 두개강내외 동맥에 대해 CE-MRA (화소크기: $0.66{\times}0.66{\times}1.1$ 혹은 $1.2\;mm^3$), CTA (화소크기: $0.42{\times}0.42{\times}0.63\;mm^3$), 그리고 DSA를 모두 시행한 28명의 환자(남자20명, 여자 8명, 나이: 53-79세)를 대상으로 하였다. 세 영상검사는 40일 이내에 모두 시행되었다 (중앙값 19일, 1-40일). 두명의 경험 있는 영상의학 전문의가 영상에 대한 평가 및 미리 설정된 15개 구간의 동맥 직경의 측정을 후향적으로 시행하였다. 결과: 총 420 구간의 동맥에 대한 평가가 CE-MRA, CTA및 DSA에서 가능하였다. DSA에서 34부위의 협착 혹은 폐색 병변이 관찰되었으며, 이중 19예는 두 개강외에 15예는 두개강내에 위치하였다. DSA를 기준으로 평가하였을 때, 두개강외 혈관에서 70%이상의 혈관협착을 진단하는데 있어 CE-MRA는 민감도 94.7%, 특이도 98.7%, 양성 예측도(PPV) 90.0%, 음성예측도(NPV) 99.3% 였고, CTA는 각각 94.7%, 99.3%, 94.7%, 99.3% 였다. 두개강내 혈관의 50% 이상 혈관 협착을 진단하는데에는 CE-MRA의 민감도가 93.3%, 특이도 98.3%, 양성예측도(PPV) 77.8%, 음성예측도(NPV) 99.6%였고, CTA에서는 각각 86.7%, 97.9%, 72.2%, 99.1%였다. 결론: 대동맥궁 상부의 두개강외와 두개강내의 동맥 협착을 진단함에 있어 CE-MRA는 CTA와 비슷한 정도의 신뢰성을 보이며, 두개강내외의 의미있는 동맥 협착에 대한 선별검사로 효과적이다.

• 대한두경부종양학회지
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• 제36권2호
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• pp.27-31
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• 2020

Neck mass has various etiologies, including inflammatory, congenital, neoplastic causes. The IgG4-related disease can cause symptoms in the head and neck areas with an inflammatory neck mass. It also shows clinical and pathological findings from inflammation caused by immune reactions, such as lymphocyte and plasma cell infiltration, storiform fibrosis, obliteration phlebitis, and invigorated serum IgG4 levels. The treatment guideline has not been established and still under debate, but systemic glucocorticoid seems to be effective in the most cases. In this brief report, a 48-year-old male patient presented with voice change for 3 weeks. Left side paramedian vocal fold palsy was observed in the flexible laryngoscopy. About 2.5×2.0×1.2cm size, heterogeneously enhanced neck mass with irregular margin encasing left carotid artery was noted on preoperative contrast enhanced neck CT scan, and it was suspicious of left carotid body tumor. The pathology shows IgG4-related disease rather than carotid body tumors. We report this case of IgG4-related disease, which can be misdiagnosed to carotid body tumors.

• Imaging Science in Dentistry
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• 제35권2호
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• pp.111-114
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• 2005

A 15-year-old patient, who had been diagnosed and treated as Burkitt cell type acute lymphoblastic leukemia (ALL-L3) already, visited our department. He complained of gingival enlargement and loosening teeth 1 month ago. The clinical examination revealed anterior open bite, gingival enlargement, and nontender swelling particularly in molar regions of both jaws. Deep periodontal pockets and severe mobility was shown on most of the teeth. The panoramic radiographs showed severe bone destruction and extrusion of the molars. The contrast enhanced CT showed multiple enhanced mass and bone marrow obliteration in both jaws. Chemotherapy was done and the swelling was subsided at 1 month later. In conclusion, radiologic findings of leukemia with soft tissue mass, known as chloroma or granulocytic sarcoma, mimic those of lymphoma, so blood test may be needed for the final diagnosis.

• 한국자기학회지
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• 제26권5호
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• pp.173-178
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• 2016

두경부와 전립선 암 환자에서 CT조영제가 방사선치료계획에 미치는 영향을 확인하고 선량계산 정확성 향상을 위하여 본 연구를 실시하였다. 30명의 환자에 대하여 Pinnacle 8.0 시스템을 이용하여 조영제에 의한 조직의 전자밀도 변화를 측정하였으며 각각의 방사선치료계획을 통한 선량계산을 실시하였다. Pinnacle과 Tomotherapy planning 시스템을 이용하여 각각의 전자밀도와 3D 입체조형방사선치료(3D CRT)와 세기변조방사선치료(IMRT)계획을 수립하였다. 조영제에 의한 전자밀도의 변화는 4%이하로 두경부: 표적용적 2.1%, 이하선 1.9%, 하악선 3.6%, 혀 0.9%, 척수 0.3%, 식도 2.6%, 하악골 0.1%, 전립선: 표적용적 0.7%, 림프절 1.1%, 방광 1.2%, 직장 1.5%, 소장 1.2%, 대장 0.6%, penile bulb 0.8%, 대퇴골두 -0.2%로 나타났다. 선량계산의 차이는 2.5% 이하의 선량 증가가 발생하였다(3D CRT: 두경부 0.69~2.51%, 전립선 0.04~1.14%, IMRT: 두경부 0.58~1.31%, 전립선 0.36~1.04%). 이러한 오차는 임상에서 허용 가능한 오차 이내이지만 영상융합(조영증강 영상과 조영증강 하지않은 영상)이나 ROI import 기능을 활용하여 조영 증강하지 않은 영상에서 선량계산을 실시한다면 1~3%의 방사선치료계획 선량 오차를 줄일 수 있을 것으로 기대된다.

• Korean Journal of Radiology
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• 제22권4호
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• pp.502-512
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• 2021

Objective: To objectively and subjectively assess and compare the characteristics of monoenergetic images [MEI (+)] and polyenergetic images (PEI) acquired by dual-energy CT (DECT) of patients with breast cancer. Materials and Methods: This retrospective study evaluated the images and data of 42 patients with breast cancer who had undergone dual-phase contrast-enhanced DECT from June to September 2019. One standard PEI, five MEI (+) in 10-kiloelectron volt (keV) intervals (range, 40-80 keV), iodine density (ID) maps, iodine overlay images, and Z effective (Z_eff) maps were reconstructed. The contrast-to-noise ratio (CNR) and the signal-to-noise ratio (SNR) were calculated. Multiple quantitative parameters of the malignant breast lesions were compared between the arterial and the venous phase images. Two readers independently assessed lesion conspicuity and performed a morphology analysis. Results: Low keV MEI (+) at 40-50 keV showed increased CNR and SNR_{breast lesion} compared with PEI, especially in the venous phase ([CNR: 40 keV, 20.10; 50 keV, 14.45; vs. PEI, 7.27; p < 0.001], [SNR_{breast lesion}: 40 keV, 21.01; 50 keV, 16.28; vs. PEI, 10.77; p < 0.001]). Multiple quantitative DECT parameters of malignant breast lesions were higher in the venous phase images than in the arterial phase images (p < 0.001). MEI (+) at 40 keV, ID, and Z_eff reconstructions yielded the highest Likert scores for lesion conspicuity. The conspicuity of the mass margin and the visual enhancement were significantly better in 40-keV MEI (+) than in the PEI (p = 0.022, p = 0.033, respectively). Conclusion: Compared with PEI, MEI (+) reconstructions at low keV in the venous phase acquired by DECT improved the objective and subjective assessment of lesion conspicuity in patients with malignant breast lesions. MEI (+) reconstruction acquired by DECT may be helpful for the preoperative evaluation of breast cancer.

• 대한영상의학회지
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• 제85권2호
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• pp.437-444
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• 2024

고유신장과 이식신장 모두에 신세포암종이 발생하는 경우는 매우 드물며, 소수의 증례만이 영문 문헌에서 보고되었다. Xp11.2전위/전사인자E3 (이하 TFE3)-재배열 신세포암종은 성인인구에서 드문 아형이다. 신장이식을 받은 어린이에서 TFE3-재배열 신세포암종이 소수의 증례로 보고되었으나, 어른에서 신장이식 후 TFE3-재배열 신세포암종이 보고된 증례는 없다. 저자들은 이식신장에 유두모양 신세포암종이, 고유신장에 TFE3-재배열 신세포암종이 있던 드문 증례를 영상 소견과 함께 보고하고자 한다. 고유신장에 생긴 TFE3-재배열 신세포암종은 5년에 걸쳐 천천히 자랐다. CT에서 약한 조영증강을 보이는 소엽 모양 종괴였으며, MRI에서는 T1 강조영상에서 높은 신호 강도를, T2 강조영상에서 낮은 신호 강도를 보였다.

• Korean Journal of Radiology
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• 제22권3호
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• pp.334-343
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• 2021

Objective: We aimed to develop a prediction model for diagnosing severe aortic stenosis (AS) using computed tomography (CT) radiomics features of aortic valve calcium (AVC) and machine learning (ML) algorithms. Materials and Methods: We retrospectively enrolled 408 patients who underwent cardiac CT between March 2010 and August 2017 and had echocardiographic examinations (240 patients with severe AS on echocardiography [the severe AS group] and 168 patients without severe AS [the non-severe AS group]). Data were divided into a training set (312 patients) and a validation set (96 patients). Using non-contrast-enhanced cardiac CT scans, AVC was segmented, and 128 radiomics features for AVC were extracted. After feature selection was performed with three ML algorithms (least absolute shrinkage and selection operator [LASSO], random forests [RFs], and eXtreme Gradient Boosting [XGBoost]), model classifiers for diagnosing severe AS on echocardiography were developed in combination with three different model classifier methods (logistic regression, RF, and XGBoost). The performance (c-index) of each radiomics prediction model was compared with predictions based on AVC volume and score. Results: The radiomics scores derived from LASSO were significantly different between the severe AS and non-severe AS groups in the validation set (median, 1.563 vs. 0.197, respectively, p < 0.001). A radiomics prediction model based on feature selection by LASSO + model classifier by XGBoost showed the highest c-index of 0.921 (95% confidence interval [CI], 0.869-0.973) in the validation set. Compared to prediction models based on AVC volume and score (c-indexes of 0.894 [95% CI, 0.815-0.948] and 0.899 [95% CI, 0.820-0.951], respectively), eight and three of the nine radiomics prediction models showed higher discrimination abilities for severe AS. However, the differences were not statistically significant (p > 0.05 for all). Conclusion: Models based on the radiomics features of AVC and ML algorithms may perform well for diagnosing severe AS, but the added value compared to AVC volume and score should be investigated further.

• Korean Journal of Radiology
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• 제22권3호
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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.

• 대한영상의학회지
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• 제84권2호
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• pp.409-417
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• 2023

목적 근치적 방광적출 후 회장 신방광형성술을 시행 받은 방광암 환자는 수술 후 혈뇨를 보일 수 있는데, 이는 종양 재발에 대한 불안을 유발할 수 있다. 그러나 종양 재발뿐 아니라 호두까기 증후군이 수술 후 혈뇨의 원인이 될 수 있으며, 이는 빈번한 증후군일 수 있음을 증명하려고 한다. 대상과 방법 2011년부터 2016년까지 근치적방광적출 후 회장 신방광형성술을 시행 받은 255명의 방광암 환자를 대상으로 조영증강 복부골반 컴퓨터단층촬영과 소변검사 소견을 후향적으로 분석하였다. 컴퓨터단층촬영에서 호두까기 증후군 소견의 유무는 좌신정맥 흐름 패턴을 평가하여 판단하였다. 소변분석에서는 총 소변검사에서 혈뇨가 양성인 비율에 따라 환자를 분류하였다. 결과 컴퓨터단층촬영에서 호두까기 증후군 소견은 135명의 환자 중 31.9%에서 나타났다. 혈뇨 양성 그룹에서는 호두까기 증후군의 소견이 없는 환자보다 있는 환자가 26% 더 많았다. 결론 호두까기 증후군의 소견은 수술 후 방광암 환자에게 빈번하였으며, 호두까기 증후군 소견과 혈뇨 사이에는 유의미한 상관관계가 있었다. 또한 호두까기 증후군 소견의 유병률은 수술 후 요로의 종양 재발률보다 높았다.

• 한국임상수의학회지
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• 제23권3호
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• pp.355-360
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• 2006

Four dogs with similar respiratory signs were referred to Veterinary Medical Teaching Hospital, Seoul National University. The clinical signs observed in these cases were anorexia, nasal discharge, sneezing, epistaxis, ocular discharge, and exophthalmoses. The routine laboratory tests revealed leukocytosis in two cases. On the skull radiographs, soft tissue density filled nasal cavity with loss of turbinate detail and increased density in frontal sinuses were found in all cases. Lysis of nasal bone was seen in two cases. Lysis of zygomatic arch was seen in one case. On computed tomography scan images, asymmetrical destruction of turbinate and nasal septum, and the superimposition of a soft tissue mass over the turbinate with peripheral contrast enhanced effect were identified in all cases. Destruction of ipsilateral orbital bone and invasion to retrobulbar region were visualized in all cases. In addition, all cases had lysis of cribriform plate. Lysis of nasal bone and destruction of hard palate were seen in two cases. Swelling of submandibular lymph node and salivary gland was seen in a case. Invasion to brain was identified in a case. All cases were diagnosed as nasal adenocarcinoma by cytology with fine needle aspiration and curettage.