Doo Kyoung Kang

Ajou University Medical Center, 수원시, Gyeonggi-do, South Korea

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Publications (44)84.99 Total impact

  • Hyunee Yim · Doo Kyoung Kang · Yong Sik Jung · Gyeong Sik Jeon · Tae Hee Kim
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    ABSTRACT: Our purpose was to evaluate imaging findings of breast cancers according to the dominant stroma type by using kinetic curve analysis and model-based perfusion parameters from dynamic contrast-enhanced MRI (DCE-MRI). From March 2011 to September 2011, 64 cancers in 64 patients were included for data analysis. Kinetic curve analysis and model based perfusion parameters (Ktrans, Kep and Ve) were obtained using DCE-MRI and post-processing software. Imaging characteristics were analyzed according to the tumor-stroma ratio and dominant stroma type. Ve values were significantly lower in tumors with more than 50% cellularity (0.44 vs 0.29, p=0.008). Histologic grade, estrogen receptor status and subtype of cancer (triple negative versus non-triple negative) were significantly different (p=0.009, p=0.019 and p=0.03, respectively). Median Kep values were different between collagen dominant, fibroblast dominant and lymphocyte dominant groups. By post hoc comparisons, mean Kep values were significantly higher in lymphocyte dominant group than collagen dominant group (p=0.003). Ktrans and Ve values were not significantly different according to dominant stroma type (p=0.351 and p=0.257, respectively). In multivariate regression analysis, nuclear grade (p=0.021) and dominant stroma type (collagen dominant, p=0.017) were independently correlated with Kep values. In terms of the dominant stroma type, the collagen dominant type showed a decrease of 0.247 in Kep values, compared with the fibroblast-dominant type (p=0.017). Ve values were significantly lower in tumors with high tumor-stroma ratio. Kep values were significantly lower in breast cancers with dominant collagen type and higher in cancers with high nuclear grade. Copyright © 2015 Elsevier Inc. All rights reserved.
    Magnetic Resonance Imaging 07/2015; DOI:10.1016/j.mri.2015.07.010 · 2.02 Impact Factor
  • Seulgi You · Doo Kyoung Kang · Yong Sik Jung · Young-Sil An · Tae Hee Kim
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    ABSTRACT: To evaluate the diagnostic performance of ultrasound (US), magnetic resonance imaging (MRI) and F-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) for the diagnosis of metastatic axillary lymph node (ALN) after neoadjuvant chemotherapy (NAC) and to find out histopathologic factors affecting the diagnostic performance of these imaging modalities. From January 2012 to November 2014, 191 consecutive patients with breast cancer who underwent NAC before surgery were retrospectively reviewed. We included 139 patients with axillary lymph node metastasis which was confirmed on fine needle aspiration or core needle biopsy at initial diagnosis. After NAC, 39 (28%) patients showed negative conversion of axillary lymph node on surgical specimens of sentinel lymph node or axillary lymph node. The sensitivity of US, MRI and PET/CT was 50% (48/96), 72% (70/97) and 22% (16/73), respectively. The specificity of US, MRI and PET-CT was 77% (30/39), 54% (21/39) and 85% (22/26), respectively. The Az value of combination of US and PET/CT was highest (0.634) followed by US (0.626) and combination of US, MRI and PET/CT (0.617). The size of tumor deposit in lymph node and estrogen receptor were significantly associated with the diagnostic performance of US (p<0.001 and p=0.009, respectively) and MRI (p=0.045 and p=0.036 respectively). The % diameter decrease, size of tumor deposit in lymph node, progesterone receptor, HER2 and histologic grade were significantly associated with the diagnostic performance of PET/CT (p=0.023, p=0.002, p=0.036, p=0.044 and p=0.008, respectively). On multivariate logistic regression analysis, size of tumor deposit within lymph node was identified as being independently associated with diagnostic performance of US [odds ratio, 13.07; 95% confidence interval (CI), 2.95-57.96] and PET/CT [odds ratio, 6.47; 95% confidence interval (CI), 1.407-29.737]. Combination of three imaging modalities showed highest sensitivity and PET/CT showed highest specificity for the evaluation of ALN metastasis after NAC. US alone or combination of US and PET/CT showed highest positive predictive value. The size of tumor deposit within ALN was significantly associated with diagnostic performance of US and PET/CT. Advances in knowledge: This study is about the diagnostic performance of US, MRI, PET/CT and combination of each imaging modalities for the evaluation of metastatic ALN after NAC. Of many histopathologic factors, only the size of tumor deposit within ALN was independent factor associated with the diagnostic performance of US and PET/CT.
    The British journal of radiology 05/2015; DOI:10.1259/bjr.20150143 · 2.02 Impact Factor
  • Young-Sil An · Doo Kyoung Kang · Yong Sik Jung · Sae-Hwan Han · Tae Hee Kim
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    ABSTRACT: Our purpose was to evaluate whether breast cancer with high metabolic-perfusion ratio would be associated with poor histopathologic prognostic factors and whether triple negative breast cancer (TNBC) would show high metabolic-perfusion ratio compared to non-triple negative breast cancer (non-TNBC). From March 2011 to November 2011, 67 females with invasive ductal carcinoma of breast who underwent both MRI and 18F-FDG PET/CT were included. Perfusion parameters including Ktrans, Kep and Ve were acquired from Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Metabolic parameters including the standardized uptake value (SUV) and volumetric metabolic parameters including metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were obtained from F-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT). In non-TNBC, SUVmax was significantly correlated with Kep (ρ=0.298, p=0.036) and Ve (ρ=-0.286, p=0.044). In TNBC, there was no significant correlation between all perfusion and metabolic parameters. Compared to non-TNBC, higher SUVmax (10.2 vs 5.3, p<0.001), higher SUVmax/Ktrans (56.02 vs 20.3, p<0.001), higher MTV50/Ktrans (7.8 vs 16.54, p<0.001), higher TLG50/Ktrans (36.49 vs 12.3, p<0.001), higher TLG50/Ve (91.34 vs 27.1 p=0.022) were significantly correlated with TNBC. Lower Ktrans (0.17 vs 0.29, p=0.017) and lower Ve (0.29 vs 0.41, p=0.011) were also significantly associated TNBC. While several perfusion parameters and metabolic parameters were correlated in non-TNBC, they were not correlated in TNBC. TNBC showed higher metabolic-perfusion ratios compared to non-TNBC. Copyright © 2015. Published by Elsevier Ireland Ltd.
    European journal of radiology 03/2015; 84(7). DOI:10.1016/j.ejrad.2015.03.026 · 2.16 Impact Factor
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    ABSTRACT: The aim of this study was to establish possible relationships among the metabolic and vascular characteristics of breast cancer using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) imaging. Sixty-seven female patients with invasive ductal breast carcinoma (age 32-79 years) who underwent FDG PET/CT and DCE-MRI prior to cancer treatment were included in the study. The maximum standardized uptake value (SUVmax), metabolic tumor volume, total lesion glycolysis (TLG), and heterogeneity factor (HF) were derived from FDG PET/CT. The DCE-MRI parameters K trans, K ep, and V e were obtained for all tumors, and relationships between the metabolic and perfusion parameters were sought via Spearman's rank correlation analysis. The prognostic significance of clinicopathological and imaging parameters in terms of recurrence-free survival (RFS) was also evaluated. No significant correlation between perfusion and metabolic parameters (p > 0.05) was found, except between SUVmax and V e (p = 0.001, rho = -0.391). Recurrence developed in 12 of the 67 patients (17.9 %, follow-up period 8-41 months). Age (p = 0.016) and HF (p = 0.027) were significant independent predictors of recurrence-free survival (RFS) upon multivariate analysis. The RFS of patients under 40 years of age was significantly poorer than that of older patients (p < 0.001). Survival of patients with more heterogeneous tumors (HF less than -0.12) was poorer than those with relatively homogenous tumors (p = 0.033). Tumors with higher levels of glucose metabolism (SUVmax values) exhibited higher tumor cellularities (V e values). Also, of the various metabolic and perfusion parameters available, tumor heterogeneity measured via FDG PET/CT (HF) may be useful in predicting RFS in breast cancer patients.
    Annals of Surgical Oncology 03/2015; DOI:10.1245/s10434-015-4526-z · 3.94 Impact Factor
  • Boram Yi · Joo Sung Sun · Hyoung-Mo Yang · Doo Kyoung Kang
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    ABSTRACT: To determine the prevalence of coronary anomalies using coronary computed tomography angiography (CCTA) and to evaluate the relationship between coronary artery anomalies and chest pain.
    01/2015; 72(4):207. DOI:10.3348/jksr.2015.72.4.207
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    Seon Young Park · Doo Kyoung Kang · Tae Hee Kim
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    ABSTRACT: Objectives: The purpose of our study was to evaluate whether strong background parenchymal enhancement would be a significant independent factor associated with positive resection margin in patients treated initially with breast conserving surgery. Materials and Methods: Retrospective evaluation of breast MRI examinations of 314 patients with breast cancer was done. Breast cancer was histologically confirmed in all patients who underwent breast conserving surgery from January 2008 to December 2010. Background parenchymal enhancement was dichotomized into weak (minimal or mild) and strong (moderate or marked) enhancement for statistical analysis. Histopathologic features of attained specimens were evaluated by an experienced pathologist and were also dichotomized for statistical analysis. Results: On univariate analysis, positive extensive intraductal component (p<0.001), strong background parenchymal enhancement (p=0.001), and HER2 positivity (p=0.08) had significant association with positive surgical margin. Tumour size, axillary lymph node metastasis, nuclear grade, histologic grade, lymphovascular invasion, estrogen receptor and progesterone receptor did not show significant correlation with positive surgical margin. On multivariate analysis, the significant independent predictors were extensive intraductal component (Odds ratio 5.68; 95% CI 2.72-11.82) and strong background parenchymal enhancement (Odds Ratio 2.39; 95% CI 1.2-4.78). Conclusion: Strong background parenchymal enhancement is significant independent factor for positive resection margin along with positive extensive intraductal component, and performing MRI during the period of lower parenchymal enhancement is needed in patients with strong background parenchymal enhancement. Advances in knowledge: As far as we know, this is the first study to reveal that BPE is a significant independent factor associated with positive resection margin.
    British Journal of Radiology 11/2014; 88(1046):20140638. DOI:10.1259/bjr.20140638 · 2.02 Impact Factor
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    ABSTRACT: Objectives To investigate the prevalence of simple pulmonary eosinophilia (SPE) and validate CT findings of SPE found on follow-up CT of oncologic patients Methods We retrospectively reviewed 6977 cases of oncologic patients who underwent chest CT. A total of 66 individuals who met criteria for having SPE were identified. CT scans were fully re-assessed by consensus of 2 radiologists in terms of characteristics of pulmonary lesions. Results The prevalence of SPE was 0.95%. A total of 193 lesions were identified and most of the lesions showed part-solid pattern (69.9%), round to ovoid contour (46.1%), ill-defined margin (90.2%), or partial halo appearance (74.8%). In addition, almost half of the lesions showed the vascular contact (49%). SPE appeared as either solitary (42.4%) or multiple lesions (57.6%). The majority of lesions were located in the periphery (76.2%), and lower lung zonal (67.4%) predominance was found. Conclusions The frequency of SPE in oncologic patients with CT findings of GGO, part-solid lesion was high (17.5%). Therefore, when key features of CT findings suggesting SPE (part-solid nodule; ill-defined margin; peripheral distribution; and lower lung zone predominance) are newly discovered on follow-up chest CT in oncologic patients, it would be useful to correlate with blood test and do short-term follow-up in order to avoid unnecessary invasive procedure.
    European Journal of Radiology 10/2014; 83(10). DOI:10.1016/j.ejrad.2014.07.004 · 2.16 Impact Factor
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    ABSTRACT: To find out any correlation between dynamic contrast-enhanced (DCE) model-based parameters and model-free parameters, and evaluate correlations between perfusion parameters with histologic prognostic factors. Model-based parameters (Ktrans, Kep and Ve) of 102 invasive ductal carcinomas were obtained using DCE-MRI and post-processing software. Correlations between model-based and model-free parameters and between perfusion parameters and histologic prognostic factors were analysed. Mean Kep was significantly higher in cancers showing initial rapid enhancement (P = 0.002) and a delayed washout pattern (P = 0.001). Ve was significantly lower in cancers showing a delayed washout pattern (P = 0.015). Kep significantly correlated with time to peak enhancement (TTP) (ρ = -0.33, P < 0.001) and washout slope (ρ = 0.39, P = 0.002). Ve was significantly correlated with TTP (ρ = 0.33, P = 0.002). Mean Kep was higher in tumours with high nuclear grade (P = 0.017). Mean Ve was lower in tumours with high histologic grade (P = 0.005) and in tumours with negative oestrogen receptor status (P = 0.047). TTP was shorter in tumours with negative oestrogen receptor status (P = 0.037). We could acquire general information about the tumour vascular physiology, interstitial space volume and pathologic prognostic factors by analyzing time-signal intensity curve without a complicated acquisition process for the model-based parameters. • Kep mainly affected the initial and delayed curve pattern in time-signal intensity curve. • There is significant correlation between model-based and model-free parameters. • We acquired information about tumour vascular physiology, interstitial space volume and prognostic factors.
    European Radiology 02/2014; 24(5). DOI:10.1007/s00330-014-3100-6 · 4.34 Impact Factor
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    11/2013; 1(1):28-34. DOI:10.14449/jbd.2013.1.6
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    11/2013; 1(1):42-44. DOI:10.14449/jbd.2013.1.7
  • Jeehyun Ma · Doo Kyoung Kang · Jae-Ik Bae · Kyung Joo Park · Joo Sung Sun
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    ABSTRACT: 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.
    American Journal of Roentgenology 11/2013; 201(5):W707-11. DOI:10.2214/AJR.12.8517 · 2.74 Impact Factor
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    ABSTRACT: MRI and PET/CT are useful for assessing breast cancer patients after neoadjuvant chemotherapy (NAC). To investigate the utility of MRI and PET/CT in the prediction of pathologic response to neoadjuvant chemotherapy using Miller-Payne grading system in patients with breast cancer. From January 2008 to December 2010, 59 consecutive patients with pathologically proven breast cancer, who underwent neoadjuvant chemotherapy followed by surgery were retrospectively enrolled. The maximal diameter decrease rate and volume reduction rate by three-dimensional (3D) MRI and standardized uptake value (SUV) reduction rate by PET/CT were calculated and correlated with the Miller-Payne grading system using the Spearman rank correlation test. Patients with Miller-Payne grades 1 or 2 were classified into the non-responder group and patients with grades 3, 4, and 5 were in the responder group. To differentiate between responders and non-responders, receiver-operating characteristic (ROC) analysis was performed. The volume reduction rate was 64.87 ± 46.95, diameter decrease rate was 48.09 ± 35.02, and SUV decrease rate was 62.10 ± 32.17. Among three parameters, the volume reduction rate was most correlated with histopathologic grades of regression (ρ = 0.755, P <0.0001) followed by diameter decrease rate (ρ = 0.660, P < 0.0001), and SUV decrease rate of primary breast mass (ρ = 0.561, P = 0.0002). The area under the ROC curve (Az) value was largest in the volume reduction rate (Az = 0.9), followed by SUV decrease rate (Az = 0.875), and diameter decrease rate (Az = 0.849). The best cut-offs for differentiating responders from non-responders in the ROC curve analysis were a 50% decrease in diameter, 68.9% decrease in volume, and 60.1% decrease in SUV after NAC. Volumetric measurement using 3D MRI combined with conventional diameter measurement may be more accurate to evaluate pathologic response after NAC.
    Acta Radiologica 08/2013; 55(4). DOI:10.1177/0284185113498720 · 1.35 Impact Factor
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    ABSTRACT: Neoadjuvant chemotherapy is the standard treatment for patients with locally advanced breast cancer and is increasingly considered for patients with operable disease. Recently, as many clinical trials have demonstrated favorable outcomes of anthracycline-taxane based regimen, this approach has been widely used in the neoadjuvant setting. We compared women who received adriamycine and docetaxel (AD) with adriamycin, cyclophosphamide followed by paclitaxel (AC-T) as neoadjuvant chemotherapy. The AD group was scheduled for six cycles of AD (50 mg/m(2) and 75 mg/m(2), respectively) at a 3-week interval. The AC-T group was scheduled for four cycles of adriamycin and cyclophosphamide (50 mg/m(2) and 500 mg/m(2), respectively) followed by four cycles of paclitaxel (175 mg/m(2)) at a 3-week interval. The responses of chemotherapy were equivalent (overall response rate [AD, 75.7% vs. AC-T, 80.9%; P = 0.566], pathologic complete response [pCR] rate [breast and axilla: AD, 10.8% vs. AC-T, 12.8%; P = 1.000; breast only: AD, 18.9% vs. AC-T, 14.9%, P = 0.623], breast conserving surgery rate [P = 0.487], and breast conserving surgery conversion rate [P = 0.562]). The pCR rate in the breast was higher in the human epidermal growth factor receptor 2 (HER2) positive cases (HER2 positive 33.3% vs. negative 10%, P = 0.002). Although nonhematologic toxicities were comparable, hematologic toxicities were more severe in the AD group. Most women in the AD group suffered from grade 3/4 neutropenia (P < 0.001) and neutropenic fever (P < 0.001). Tumor responses were not different in various variables between the two groups. However, AC-T was a more tolerable regimen than AD in patients with breast cancer receiving neoadjuvant chemotherapy.
    Journal of the Korean Surgical Society 07/2013; 85(1):7-14. DOI:10.4174/jkss.2013.85.1.7 · 0.62 Impact Factor
  • Doo Kyoung Kang · Tae Hee Kim · Tae Sun Han · Ku Sang Kim · Hyunee Yim
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    ABSTRACT: PURPOSE: This study examined the ability of magnetic resonance imaging (MRI) enhancement features to predict the response to neoadjuvant chemotherapy (NAC) in patients with breast cancer. METHODS: This retrospective study included 107 patients with breast cancer. All patients underwent a baseline breast MRI before NAC and follow-up MRI a mean of 3.7 months later. Breast MRI scans were evaluated using the Breast Imaging Reporting and Data System MRI lexicon. In addition, whole-breast vascularity (WBV) in the cancer-bearing breast was graded according to increased vessel number in comparison with the contralateral breast. Histopathologic tumor regression was graded semiquantitatively based on the Miller-Payne grading system. The ability of each MRI feature to predict the response was evaluated using a logistic regression analysis. Correlations between changes in MRI features and response were also evaluated using the Spearman rank correlation test. RESULTS: There were 73 responders (68%), including 59 partial and 14 complete responders. No significant difference in baseline MRI features was found between the responders and nonresponders, except for tumor size (P = 0.044). No dynamic enhancement feature on baseline MRI was useful for the early prediction of a response. In addition, an increased WBV did not predict a response, and the WBV change on the follow-up MRI was not correlated with the response. However, the change in the initial enhancement pattern (P = 0.007) and kinetic curve type (P = 0.003) were significantly correlated with response. CONCLUSIONS: No baseline MRI feature described using the Breast Imaging Reporting and Data System MRI lexicon was useful for early prediction of the response to NAC.
    Journal of computer assisted tomography 05/2013; 37(3):432-439. DOI:10.1097/RCT.0b013e31828386ae · 1.60 Impact Factor
  • Sun Jun Ahn · Doo Kyoung Kang · Joo Sung Sun · Myeong-Ho Yoon
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    ABSTRACT: 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.
    Journal of computer assisted tomography 05/2013; 37(3):387-394. DOI:10.1097/RCT.0b013e318282d61c · 1.60 Impact Factor
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    ABSTRACT: Granulocytic sarcoma is a localized extramedullary solid tumor composed of immature myeloid cell and is usually associated with acute myeloid leukemia or myelodysplastic syndrome. Although it can involve any site, commonly in lymph nodes, skin, bone and soft tissue, the involvement of breast is unusual. Especially, the involvement of the breast as a pattern of relapse after bone marrow transplantation is extremely rare. We have experienced 2 cases of granulocytic sarcoma after bone marrow transplantation. One case was a 39-year-old woman with right breast mass diagnosed with granulocytic sarcoma. She had received an unrelated bone marrow transplantation due to biphenotype acute leukemia 3 years before our presentation. Another case was a 48-year-old woman with acute myeloid leukemia, who was diagnosed with granulocytic sarcoma on both breasts 8 months after allogenic bone marrow transplantation. We also discuss the clinicopathologic features of granulocytic sarcoma in breast after bone marrow transplantation.
    Journal of Breast Cancer 03/2013; 16(1):112-116. DOI:10.4048/jbc.2013.16.1.112 · 1.32 Impact Factor
  • Eun Young Kim · Doo Kyoung Kang · Joo Sung Sun · So-Yeon Choi
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    ABSTRACT: To evaluate the progression of coronary atherosclerotic plaque during follow-up, and its association with cardiovascular risk factors.
    01/2013; 69(6):437. DOI:10.3348/jksr.2013.69.6.437
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    ABSTRACT: PURPOSE We conducted a study to evaluate the usefulness of automatic tube current modulation(ATCM) in computed tomography (CT) of ultra (very) low-dose chest CT screening to decrease radiation dose without degradation of image quality. METHOD AND MATERIALS Ultra low-dose chest CT data from 60 subjects were acquired at 20mAs and 100kVp on a 64-row Multidetector CT scanner. Group 1 (30 subjects) underwent ultra low-dose chest CT with fixed tube current of 20mAs and group 2 (30 subjects) underwent ultra low-dose chest CT with ATCM of 20 mAs. There was no significant difference of body mass index in both groups (group 1=24.13+3.14 and group 2=24.35+4.32, p>0.05). Total of 60 data sets were randomly arranged to be evaluated. Radiologist blinded to current technique evaluated images. For radiation dose description, CT radiation dose descriptors were recorded following completion of the CT examination for all image data sets. Qualitative image noises (5-point scale), visibility of small structures (5-point scale) were assessed at lung apex, mid and base of lung, aorta, and liver. RESULTS Radiation dose of group 2 (ATCM) was significantly lower than that of group 1 (group 1= 31.64+2.0 and group 2=25.43+5.9, p<0.0001). However, subjective image noises in lung parenchyma and soft tissue were substantially lower in group 1 (fixed tube current) (p<005). Furthermore, in terms of visibility of small structures, fixed tube current technique was superior to ATCM technique for depicting small structure of lung (p<0.005). CONCLUSION In the application of ultra (very) low-dose chest CT, ATCM technique would not be adequate to keep image quality compared to fixed tube current technique. A larger study including more subjects is required to make the conclusion generalizable. CLINICAL RELEVANCE/APPLICATION This preliminary study suggests ATCM may be inadequate in ultra low-dose chest CT in two aspects: 1) degradation of subjective image quality 2) lower power to depict small structures of lung.
    Radiological Society of North America 2012 Scientific Assembly and Annual Meeting; 11/2012
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    ABSTRACT: PURPOSE To evaluate the progression of atherosclerotic plaque during the follow-up interval and to compare it with the cardiovascular risk profile. METHOD AND MATERIALS One hundred and sixty-seven patients underwent repeated 64-slice MDCT with mean interval of 2.2 ± 0.9 years. The progression of atherosclerotic plaque volume between baseline and follow-up was assessed for the lesion. Coronary lesions detected on MDCT were grouped according to plaque composition. Calcified plaque volume was measured using non-contrast calcium scoring examination. Non-calcified plaque volume was measured using contrast enhanced coronary CT angiography and a commercially available plaque analysis tool (Aquarius, TeraRecon). The National Cholesterol Education Program (NCEP) risk categories, calcified plaque volume and non-calcified plaque volume were compared between baseline and follow-up by using a paired t-test. Absolute and percentage changes of each plaque volume were also calculated, and compared each other by using Mann-Whitney test. RESULTS In the follow-up period, the total Agatston calcium score was significantly increased (15.3mm3 vs. 27.2mm3, p<0.001), whereas the NCEP risk categories were unchanged (p=0.058). The calcified plaque volume (13.7mm3 vs. 22.0 mm3, p<0.001), non-calcified plaque volume (46.3mm3 vs. 147.4mm3, p<0.001) and stenosis degree (30.4% vs. 39.5%, p<0.001) of the lesions were significantly increased on follow-up CT. Median plaque percentage change was greater(p=0.028) in fatty plaque(44.7%, 95% CI 19.9 – 229.6%) than in calcified plaque (29.8%, 95% CI 15.1 – 44.6%). CONCLUSION Coronary plaque burden significantly increased on follow-up CT, but the rate of progression was dependent on plaque composition and was greater for fatty plaque than for calcified plaque. CLINICAL RELEVANCE/APPLICATION Contrast-enhanced MDCT may be a reliable modality to evaluate the progression of coronary atherosclerotic plaque.
    Radiological Society of North America 2012 Scientific Assembly and Annual Meeting; 11/2012
  • Miran Han · Tae Hee Kim · Doo Kyoung Kang · Ku Sang Kim · Hyunee Yim
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    ABSTRACT: The purpose of this study was to compare adjacent vessel sign, increased ipsilateral whole-breast vascularity, and various MRI features as described in the American College of Radiology BI-RADS MRI lexicon with histopathologic predictors in patients with unilateral breast cancer. We retrospectively evaluated breast MRI examinations of 249 patients with histologically confirmed breast cancer. In addition to the BI-RADS MRI lexicon, the adjacent vessel sign and increased ipsilateral whole-breast vascularity of the cancer-bearing breast were evaluated by two independent observers. MRI features were then correlated with histopathologic prognostic factors. The adjacent vessel sign was significantly (p = 0.023 to p < 0.001) associated with tumor size, lymph node metastasis, distant metastasis, nuclear grade, and expression of estrogen and progesterone receptors. Increased ipsilateral whole-breast vascularity was significantly associated with all histopathologic predictors (p = 0.017 to p < 0.001). In multivariate analysis, the significant and independent predictors were a spiculated margin and rim enhancement for negative estrogen and progesterone receptors, a kinetic curve type for higher histologic grade, and an increased ipsilateral whole-breast vascularity for larger tumor size, lymph node metastasis, distant metastasis, higher nuclear grade, and higher histologic grade. In conjunction with the standard BI-RADS MRI lexicon, the adjacent vessel sign and increased ipsilateral whole-breast vascularity may serve as additional predictors of a poor prognosis.
    American Journal of Roentgenology 10/2012; 199(4):921-8. DOI:10.2214/AJR.11.7895 · 2.74 Impact Factor