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Featured researches published by Joo g Sun.


Lung Cancer | 2009

Clinical usefulness of the fluorodeoxyglucose (FDG)-PET maximal standardized uptake value (SUV) in combination with CT features for the differentiation of adenocarcinoma with a bronchioloalveolar carcinoma from other subtypes of non-small cell lung cancers

Joo Sung Sun; Kyung Joo Park; Seung Soo Sheen; Joon-Kee Yoon; Seok Nam Yoon; Kyi Beom Lee; Sung Chul Hwang

PURPOSE To evaluate the clinical usefulness of fluorodeoxyglucose (FDG)-PET maximal SUV in combination with CT features for differentiation of adenocarcinoma with bronchioloalveolar carcinoma (BAC) from other subtypes of non-small cell lung cancer (NSCLC). MATERIALS AND METHODS This retrospective study included 125 patients (104 men and 21 women; mean age, 64 years) who underwent CT and subsequent FDG-PET examinations for preoperative evaluation and underwent curative intent operation with the final diagnoses of NSCLC made by surgical histopathology. We categorized NSCLC into adenocarcinoma with BAC feature and other subtypes. Finally, there were 16 cases of adenocarcinoma with BAC and 109 cases of other NSCLC subtypes included in the study. Several CT features of lung cancer were analyzed, including tumor size, presence of spiculation, margin (irregular or smooth), pattern of the mass (pure solid, pure ground glass opacity and mixed), associated pleural effusion and location (center, mid and periphery). Maximal SUV and visual scores of FDG uptakes of primary NSCLC were evaluated. The diagnostic performances of CT alone, PET alone, and combination of two modalities to predict adenocarcinoma with BAC from other subtypes of NSCLC were calculated. RESULTS A nodule with a mixed pattern with partly solid and ground glass opacity was significantly more frequent CT feature of an adenocarcinoma with BAC (8/16, 50%) as compared with the other subtypes (2/109, 1.8%) (p<0.0001). Maximal SUV of adenocarcinoma with BAC (mean=7.2) was significantly lower than that of other subtypes of NSCLC (mean=13.33) (p<0.0001). Sensitivity, specificity, PPV, and NPV of CT for differentiating adenocarcinoma with BAC from other subtypes was 50% (8/16), 98.2% (107/109), 80% (8/10), and 93% (107/115), respectively. Sensitivity, specificity, PPV, and NPV of FDG-PET was 68.8% (11/16), 86.2% (94/109), 42.3% (11/26), and 94.9% (94/99), respectively. Sensitivity, specificity, PPV, and NPV of combination of two modalities was 81.3% (13/16), 85.3% (93/109), 44.8% (13/29), 96.9% (93/96), respectively. CONCLUSION Careful combined assessment of the FDG-PET maximal SUV and CT findings have the potential to differentiate an adenocarcinoma with BAC from other NSCLC subtypes, such as a pure BAC. These findings might be useful for imaging interpretations and will help initial planning of NSCLC management.


American Journal of Cardiology | 2011

Usefulness of Combined Assessment With Computed Tomographic Signs of Right Ventricular Dysfunction and Cardiac Troponin T for Risk Stratification of Acute Pulmonary Embolism

Doo Kyoung Kang; Joo Sung Sun; Kyung Joo Park; Hong Seok Lim

The aim of this study was to evaluate the incremental value of combined assessment with computed tomographic (CT) signs of right ventricular (RV) dysfunction and cardiac troponin T level for predicting early death or adverse outcomes due to acute pulmonary embolism (PE). One hundred seventy-three non-high-risk patients with acute PE, confirmed by CT pulmonary angiography, were retrospectively evaluated. The area under the curve and hazard ratio of CT signs and troponin T levels were compared for predicting early death or adverse outcomes. Patients were classified into intermediate- and low-risk groups on the basis of CT signs and troponin T levels, and mortality was compared. Seventeen patients (9.8%) died within 3 months. Early mortality of intermediate-risk patients (14% to 19%) was higher than that of low-risk patents (2% to 6%). A ratio of RV volume to left ventricular volume > 1.5 had the highest area under the curve (0.709) and hazard ratio (5.402) for predicting early death. The combination of CT signs and elevated troponin T level had an increased area under the curve and hazard ratio for predicting early death and adverse outcomes compared to those of CT signs or elevated troponin T level alone. In conclusion, the combined assessment of the ratio of RV volume to left ventricular volume and an elevated troponin T level provided incrementally more prognostic information in non-high-risk patients with acute PE compared to the single predictor of CT signs or troponin T level.


American Journal of Roentgenology | 2010

CT Findings in Patients With Pericardial Effusion: Differentiation of Malignant and Benign Disease

Joo Sung Sun; Kyung Joo Park; Doo Kyoung Kang

OBJECTIVE This study was designed to validate the usefulness of a CT finding of abnormal pericardial thickening and to investigate the value of associated thoracic changes in predicting the presence of malignant pericardial effusion. MATERIALS AND METHODS Seventy-four consecutively registered patients with pericardial effusion detected with transthoracic echocardiography were included in the study. The patients fulfilled the following criteria: undergoing pericardial fluid cytologic examination or pericardial tissue biopsy and undergoing chest CT examination less than 30 days after pericardial fluid or tissue examination. CT images were reviewed for the presence of pericardial thickening, the pattern of pericardial thickening, and the presence of pleural effusion and mediastinal lymph node enlargement. RESULTS Twenty-eight cases of malignant and 46 cases of benign pericardial effusion were identified. Mean pericardial thickening was greater in association with malignant disease (7.25 +/- 2.91 mm) than with benign disease (4.11 +/- 1.39 mm) (p < 0.05). Abnormal pericardial thickening (p < 0.05) and mediastinal lymph node enlargement (p < 0.001) were statistically significant findings of malignant pericardial effusion. The sensitivity of abnormal pericardial thickening was 42.9% and that of mediastinal lymph node enlargement was 60.7%. CONCLUSION CT findings of irregular pericardial thickening and mediastinal lymphadenopathy have the potential to be reliably specific findings suggesting the presence of malignant pericardial effusion. It would be useful, however, to obtain pericardial fluid or tissue for cause-based management of pericardial effusion, especially in patients with malignant disease.


Acta Radiologica | 2008

Comparison Study of Intraarticular and Intravenous Gadolinium-Enhanced Magnetic Resonance Imaging of Cartilage in a Canine Model

Kyu-Sung Kwack; Jae Hyun Cho; Myung Soon Kim; Choon-Sik Yoon; Yeo Seung Yoon; Jae Won Choi; Jong Won Kwon; Byoung-Hyun Min; Joo Sung Sun; Sun Yong Kim

Background: Magnetic resonance (MR) imaging and measurement of glycosaminoglycan (GAG) have potential for characterization of hyaline articular cartilage. Recently, some reports have demonstrated the potential of direct administration of contrast media for MR imaging of cartilage. Purpose: To prove the feasibility of intraarticular gadolinium-enhanced MR imaging of cartilage (iGEMRIC) and T1 relaxation mapping of the articular cartilage in vivo with intraarticular injection of Gd-DTPA2−. Material and Methods: Five healthy beagle dogs underwent MR imaging and T1 relaxation mapping of the knee joints of both hind legs. The delayed gadolinium-enhanced MR imaging of cartilage (dGEMRIC) and iGEMRIC techniques were interchanged with MR imaging. For dGEMRIC, a double routine dose of Gd-DTPA2− (0.2 mM/kg) was administered intravenously. For iGEMRIC, 2.5 and 1.25 mmol/l saline-diluted Gd-DTPA2− solutions were separately injected into the right and left knee joints, respectively, prior to MR imaging. Color-coded T1 maps of 20 femoral condyles were obtained from the dGEMRIC and iGEMRIC images. The signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and glycosaminoglycan (GAG) delineation of articular cartilage were compared between the dGEMRIC and iGEMRIC techniques. Results: The mean SNR was higher with dGEMRIC than with iGEMRIC, but the difference was not statistically significant (P = 0.174). The mean (±SD) CNR was higher with iGEMRIC (−11.6±3.4) than with dGEMRIC (−16.7±4.0; P = 0.000), although the absolute value of the CNR was higher with dGEMRIC. The layering and gradient distribution of GAG were more clearly visualized on the iGEMRIC images. The mean scores of GAG delineation with dGEMRIC and iGEMRIC were 0.7±0.6 and 2.2±1.7, respectively. The iGEMRIC method better visualized GAG distribution (P = 0.001). Conclusion: Although the SNR did not differ significantly between the iGEMRIC and dGEMRIC techniques, the color-coded T1 map produced with iGEMRIC allowed better cartilage evaluation. Thus, iGEMRIC exhibits the useful features of both MR arthrography and dGEMRIC, and provides a color-coded T1 map that is useful for diagnosing early articular cartilage damage.


Journal of Computer Assisted Tomography | 2005

MR findings in eosinophilic infiltration of the liver

Joo Sung Sun; Jai Keun Kim; Je Hwan Won; Ki Myung Lee; Jae Youn Cheong; Young Bae Kim

Objective: This study describes the findings of magnetic resonance imaging (MRI) of focal eosinophilic infiltration of the liver. Methods: Contrast-enhanced MR images of 8 patients with focal hepatic eosinophilic infiltration were reviewed retrospectively. We evaluated the signal intensity of focal lesions in T1-weighted andT2-weighted images and the pattern of enhancement in a dynamic contrast study. Results: A total 22 focal hepatic lesions were observed; the lesions were isointense (55%) or hypointense (45%) on T1-weighted images and isointense (14%) or hyperintense (86%) on T2-weighted images. The arterial phase of the contrast study revealed 11 hyperintense lesions (50%). During the portal and delayed phases, 18 (82%) and 17 lesions (77%) were hyperintense, respectively. Conclusion: The focal eosinophilic infiltrations showed homogeneous enhancement in the portal and delayed phases in the dynamic contrast MR study. These findings should help to distinguish focal eosinophilic infiltration, especially from metastasis in patients with malignancy.


European Radiology | 2008

Primary pulmonary malignant fibrous histiocytoma mimics pulmonary artery aneurysm with partial thrombosis: various radiologic evaluations

Hyun Woo Noh; Kyung Joo Park; Joo Sung Sun; J. Won; Kyu-Sung Kwack; Ho Choi; Kyi Beom Lee; Joo Hun Park

Primary pulmonary malignant fibrous histiocytoma (MFH) is very rare, so only a few imaging features have been reported. We report one case of rapidly growing primary pulmonary MFH mimicking a partially thrombosed pulmonary artery aneurysm and its radiologic findings, including multidetector row computed tomography (MDCT), conventional angiography, and fluorodeoxyglucose-positron emission tomography CT ([18F] FDG-PET/CT). On multi-phasic MDCT, this mass mimicked a pulmonary artery aneurysm with partial thrombosis. However, pulmonary artery aneurysm was excluded and suggested as a hypervascular parenchymal mass by subsequent conventional angiography. On [18F] FDG-PET/CT, it was a highly metabolic mass, showing a maximal standard uptake value (SUV) 12.1. Although primary pulmonary MFH is very rare and has no specific imaging findings, our experience might be helpful to differentiate a hypervascular pulmonary mass.


American Journal of Roentgenology | 2008

Correlation of Whole-Breast Vascularity with Ipsilateral Breast Cancers Using Contrast-Enhanced MDCT

Doo Kyoung Kang; Eun Jin Kim; Ho Sung Kim; Joo Sung Sun; Yong Sik Jung

OBJECTIVE The purpose of our study was to assess the increase in whole-breast vascularity in patients with unilateral breast cancer and correlate that increase with prognostic factors of breast cancer. MATERIALS AND METHODS We performed 16-MDCT on 143 consecutive patients with histologically confirmed breast cancer. One hundred three of these 143 patients were finally enrolled in the study after exclusion of patients with bilateral breast cancer, previous history of neoadjuvant chemotherapy, breast surgery, or lack of surgical confirmation. Breast vascularity was assessed according to the number, length, and conspicuity of vessels on maximum-intensity-projection images. Increase of whole-breast vascularity of the cancer-bearing breast was categorized as not increased, mild, moderate, or prominent compared with the contralateral breast. Breast vascularity was then correlated to prognostic factors including tumor size, lymph node status, cancer stage, nuclear and histologic grade, presence of an extensive intraductal component, presence of hormone receptors, and expression of C-erb-B2. RESULT . In 77 (74.8%) of 103 patients, breast cancers were found to be associated with ipsilateral increased whole-breast vascularity. In the 77 patients with increased vascularity, prominent, moderate, and mild vascularity were shown in 21 (27.3%), 23 (29.9%), and 33 (42.9%) patients, respectively. Ipsilateral increased vascularity was related to tumor size, lymph node status, cancer stage, nuclear grade, and histologic grade. The presence of extensive intraductal component and hormone receptors and the expression of C-erb-B2 were not related to ipsilateral increased vascularity. CONCLUSION Breast cancers were found to be associated with ipsilateral increased whole-breast vascularity in a significant percentage of patients. Increased whole-breast vascularity indicated the growth and metastatic potential of a breast cancer.


Journal of Computer Assisted Tomography | 2013

Accuracy and predictive value of coronary computed tomography angiography for the detection of obstructive coronary heart disease in patients with an Agatston calcium score above 400.

Sun Jun Ahn; Doo Kyoung Kang; Joo Sung Sun; Myeong-Ho Yoon

Purpose We assessed the accuracy of coronary computed tomography angiography (CTA) in patients with an Agatston calcium score (ACS) of greater than 400 by comparing it with invasive coronary angiography (ICA), and we evaluated the predictive value of CTA for obstructive coronary heart disease (CHD) compared with traditional clinical risk assessment. Methods A total of 253 patients who had an ACS of greater than 400 were enrolled in this study. The degree of coronary stenosis was visually and quantitatively estimated by postprocessing imaging using 15-segment coronary models. All patients underwent ICA after a mean (SD) of 34 (24) days, and the degree of coronary stenosis was compared with the results of CTA. Results Computed tomography angiography accurately diagnosed significant stenosis in 204 (99.0%) of 206 patients and in 649 (83.5%) of 777 segments. When the patients were considered based on their ACS (group A, 400 < ACS ⩽ 1000, vs group B, ACS > 1000), group B showed lower specificity (9.1% vs 41.7%) and poorer agreement (k = 0.149 vs 0.495) than for ICA. By segment-based analysis, the agreement between CTA and ICA was good (k = 0.729), and there was no significant difference between groups A (k = 0.728) and B (k = 0.727). Computed tomography angiography was the most powerful predictor (odds ratio = 52.645, P < 0.001), whereas the 10-year CHD risk and pretest probability were not significantly correlated with obstructive CHD. Conclusions Despite good overall diagnostic accuracy, coronary CTA in this group of patients was limited by low specificity. However, CTA was a better predictor of obstructive CHD compared with clinical predictors, and it avoided unnecessary ICA, even in patients with extensive coronary artery calcification.


American Journal of Roentgenology | 2013

Value of MDCT in Diagnosis and Management of Esophageal Sharp or Pointed Foreign Bodies According to Level of Esophagus

Jeehyun Ma; Doo Kyoung Kang; Jae-Ik Bae; Kyung Joo Park; Joo Sung Sun

OBJECTIVE The purpose of this study was to validate the usefulness of MDCT for diagnosis of a sharp or pointed esophageal foreign body according to esophageal level. MATERIALS AND METHODS Forty-two patients with a history of sharp or pointed foreign body ingestion were reviewed retrospectively. Two observers interpreted the CT and the conventional radiography datasets separately. If a foreign body was directly identified, it was regarded as a positive finding. Even if no high-density foreign body was found, detection of a secondary finding was considered to be a positive finding. Diagnostic performance of MDCT and conventional radiography were compared according to esophageal level. Final diagnosis was made by esophagoscopy or surgery in addition to the clinicoradiologic result. RESULTS MDCT was statistically superior to conventional radiography for diagnosis of a thoracic esophageal foreign body for both observers (p < 0.001 for each). No significant difference in sensitivity between CT and conventional radiography for diagnosis of cervical esophageal foreign body was noted regardless of observer. Both observers could identify all complicated conditions with MDCT regardless of esophageal level. However, in two of three cases of complicated thoracic esophageal foreign bodies, neither observer could detect foreign bodies on conventional radiography; furthermore, the observers could not identify pneumomediastinum. CONCLUSION In cases of sharp or pointed foreign body ingestion, if the result of an initial inspection of oro- and hypopharynx reveals negative findings, the first imaging modality should be MDCT for better diagnosis and management.


Journal of Korean Medical Science | 2010

Emphysema as a risk factor for the outcome of surgical resection of lung cancer.

Sung Ah Lee; Joo Sung Sun; Joo Hun Park; Kyung Joo Park; Sung Soo Lee; Ho Choi; Seung Soo Sheen; Woo Young Chung; Keu Sung Lee; Kwang Joo Park; Sung Chul Hwang

It is unclear whether emphysema, regardless of airflow limitation, is a predictive factor associated with survival after lung cancer resection. Therefore, we investigated whether emphysema was a risk factor associated with the outcome after resection for lung cancer. This study enrolled 237 patients with non small cell lung cancer with stage I or II who had surgical removal. Patient outcome was analyzed based on emphysema. Emphysema was found in 43.4% of all patients. Patients with emphysema were predominantly men and smokers, and had a lower body mass index than the patients without emphysema. The patients without emphysema (n=133) survived longer (mean 51.2±3.0 vs. 40.6±3.1 months, P=0.042) than those with emphysema (n=104). The univariate analysis showed a younger age, higher FEV1/FVC, higher body mass index, cancer stage I, and a lower emphysema score were significant predictors of better survival. The multivariate analysis revealed a younger age, higher body mass index, and cancer stage I were independent parameters associated with better survival, however, emphysema was not. This study suggests that unfavorable outcomes after surgical resection of lung cancer should not be attributed to emphysema itself.

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