Doo Kyoung Kang

Publications of Doo Kyoung Kang

• Magnetic resonance imaging patterns of tumor regression after neoadjuvant chemotherapy in breast cancer patients: correlation with pathological response grading system based on tumor cellularity.

  Authors: Tae Hee Kim, Doo Kyoung Kang, Hyunee Yim, Yong Sik Jung, Ku Sang Kim, Seok Yun Kang

  Journal of computer assisted tomography. 03/2012; 36(2):200-6.

  The objectives of the study were to analyze the tumor shrinkage pattern on magnetic resonance imaging (MRI) after neoadjuvant chemotherapy and to evaluate whether there is any difference in shrinkageThe objectives of the study were to analyze the tumor shrinkage pattern on magnetic resonance imaging (MRI) after neoadjuvant chemotherapy and to evaluate whether there is any difference in shrinkage pattern between pathological responder and nonresponder groups. In addition, we wanted to compare tumor diameter obtained from MRI with histological diameter according to the tumor shrinkage pattern. Between July 2008 and December 2010, 55 consecutive patients (56 lesions) with pathologically proven breast cancer who underwent neoadjuvant chemotherapy followed by surgery were retrospectively enrolled. The shrinkage pattern was classified into 4 categories: I (concentric shrinkage without surrounding lesion), II (concentric shrinkage with surrounding lesions), III (shrinkage with residual multinodular lesions, and IV (diffuse contrast enhancement in whole quadrants). Histological regression was scored on a 5-point scale regarding tumor cellularity reduction (Miller-Payne grading system). Patients with Miller-Payne grade 1 or 2 were classified into the nonresponder group, and patients with grade 3, 4, or 5 were in the responder group. Of 56 lesions, pattern I was seen in 29 lesions, pattern II in 13 lesions, pattern III in 5 lesions, and pattern IV in 4 lesions. Three lesions were not visualized on MRI after neoadjuvant chemotherapy, and 2 lesions were increased in size. There was a statistically significant difference in the tumor shrinkage pattern between responder and nonresponder groups (P = 0.017). All 5 lesions with type III shrinkage pattern were found in the responder group, and all 4 lesions with pattern IV were in the nonresponder group. Magnetic resonance imaging diameter of lesions with types I, II, and IV patterns showed significant correlation with the histological diameter. Among them, the correlation factor was highest in pattern IV (ρ = 0.94, P < 0.001) followed by pattern I (ρ = 0.67, P < 0.01) and pattern II (ρ = 0.502, P = 0.08). However, in type III shrinkage pattern, tumor size measured on MRI was not significantly correlated with histological size (P = 0.87). Types III and I shrinkage patterns were more frequently observed in the pathological responder group, and type IV was more frequently noted in the nonresponder group. Tumor diameter measured on MRI showed strong correlation with histological diameter in lesions with types I and IV shrinkage patterns, whereas lesions with type III did not show significant correlation. Type II pattern showed similar frequencies between the 2 groups and moderate correlation between sizes obtained from MRI and histology.

• Differential diagnosis in idiopathic granulomatous mastitis and tuberculous mastitis.

  Authors: Hee Ri Na Seo, Kuk Young Na, Hyun Ee Yim, Tae Hee Kim, Doo Kyoung Kang, Ki Keun Oh, Seok Yun Kang, Young-Sil An, Mison Chun, Woojae Kim, Rae Woong Park, Yong Sik Jung, Ku Sang Kim

  Journal of breast cancer. 03/2012; 15(1):111-8.

  Idiopathic granulomatous mastitis (IGM) is a rare chronic inflammatory disease of unknown etiology. The diagnosis of IGM requires that other granulomatous lesions in the breast be excluded.Idiopathic granulomatous mastitis (IGM) is a rare chronic inflammatory disease of unknown etiology. The diagnosis of IGM requires that other granulomatous lesions in the breast be excluded. Tuberculous mastitis (TM) is also an uncommon disease that is often difficult to differentiate from IGM. The purpose of this study is to develop a new algorithm for the differential diagnosis and treatment of IGM and TM. Medical records of 68 patients (58 with IGM and 10 with TM) between July 1999 and February 2009 were retrospectively reviewed. The mean age of the patients was 33.5 (IGM) and 40 (TM) years (p=0.018). The median follow-up was 84 months. Of the total 10 patients with TM, 5 patients had a history of pulmonary tuberculosis. The most common symptoms of the diseases were breast lump and pain. However, axillary lymphadenopathy was more seen in TM (50%) compared to IGM (20.6%) (p=0.048). TM showed more cancer-mimicking findings on radiologic study (p=0.028). In IGM, 48 patients (82.7%) underwent surgical wide excision and 21 patients (36.2%) were managed with corticosteroid therapy and antibiotics. All of the TM patients received anti-tuberculosis medications and 9 patients (90%) underwent wide excision. The mean treatment duration was 2.8 months in IGM and 8.4 months in TM. Recurrence developed in 5 patients (8.6%) in IGM and 1 patient (10%) in TM. This study shows different characteristics between IGM and TM. The IGM patients were younger and had more mastalgia symptoms than the TM patients. Axillary lymphadenopathy was seen more often in TM patients. Half of the TM patients had pulmonary tuberculosis or tuberculosis lymphadenitis. Surgical wide excision might be both therapeutic and useful for providing an exact diagnosis.

• Granular cell tumor of the male breast: two case descriptions and brief review of the literature.

  Authors: Eun Young Kim, Doo Kyoung Kang, Tae Hee Kim, Yong Sik Jung, Ku Sang Kim, Hyunee Yim

  Journal of ultrasound in medicine : official journal of the American Institute of Ultrasound in Medicine. 09/2011; 30(9):1295-301.

  A granular cell tumor of breast is a rare and usually benign tumor originating from Schwann cells. The mammographic and sonographic appearances of a granular cell tumor pose a diagnostic dilemmaA granular cell tumor of breast is a rare and usually benign tumor originating from Schwann cells. The mammographic and sonographic appearances of a granular cell tumor pose a diagnostic dilemma because of its similarity to breast malignancy. We describe 2 cases of breast granular cell tumors in male patients, which were confirmed after surgical excision and histologic examination.

• CT signs of right ventricular dysfunction: prognostic role in acute pulmonary embolism.

  Authors: Doo Kyoung Kang, Christian Thilo, U Joseph Schoepf, J Michael Barraza, John W Nance, Gorka Bastarrika, Joseph A Abro, James G Ravenel, Philip Costello, Samuel Z Goldhaber

  JACC. Cardiovascular imaging. 08/2011; 4(8):841-9.

  The purpose of this study was to compare the prognostic role of various computed tomography (CT) signs of right ventricular (RV) dysfunction, including 3-dimensional ventricular volume measurements,The purpose of this study was to compare the prognostic role of various computed tomography (CT) signs of right ventricular (RV) dysfunction, including 3-dimensional ventricular volume measurements, to predict adverse outcomes in patients with acute pulmonary embolism (PE). Three-dimensional ventricular volume measurements based on chest CT have become feasible for routine clinical application; however, their prognostic role in patients with acute PE has not been assessed. We evaluated 260 patients with acute PE for the following CT signs of RV dysfunction obtained on routine chest CT: abnormal position of the interventricular septum, inferior vena cava contrast reflux, right ventricle diameter (RVD) to left ventricle diameter (LVD) ratio on axial sections and 4-chamber (4-CH) views, and 3-dimensional right ventricle volume (RVV) to left ventricle volume (LVV) ratio. Comorbidities and fatal and nonfatal adverse outcomes according to the MAPPET-3 (Management Strategies and Prognosis in Pulmonary Embolism Trial-3) criteria within 30 days were recorded. Fifty-seven patients (21.9%) had adverse outcomes, including 20 patients (7.7%) who died within 30 days. An RVD(axial)/LVD(axial) ratio >1.0 was not predictive for adverse outcomes. On multivariate analysis (adjusting for comorbidities), abnormal position of the interventricular septum (hazard ratio [HR]: 2.07; p = 0.007), inferior vena cava contrast reflux (HR: 2.57; p = 0.001), RVD(4-CH)/LVD(4-CH) ratio >1.0 (HR: 2.51; p = 0.009), and RVV/LVV ratio >1.2 (HR: 4.04; p < 0.001) were predictive of adverse outcomes, whereas RVD(4-CH)/LVD(4-CH) ratio >1.0 (HR: 3.68; p = 0.039) and RVV/LVV ratio >1.2 (HR: 6.49; p = 0.005) were predictive of 30-day death. Three-dimensional ventricular volume measurement on chest CT is a predictor of early death in patients with acute PE, independent of clinical risk factors and comorbidities. Abnormal position of the interventricular septum, inferior vena cava contrast reflux, and RVD(4-CH)/LVD(4-CH) ratio are predictive of adverse outcomes, whereas RVD(axial)/LVD(axial) ratio >1.0 is not.

• Usefulness of combined assessment with computed tomographic signs of right ventricular dysfunction and cardiac troponin T for risk stratification of acute pulmonary embolism.

  Authors: Doo Kyoung Kang, Joo Sung Sun, Kyung Joo Park, Hong Seok Lim

  The American journal of cardiology. 07/2011; 108(1):133-40.

  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 forThe 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.

• Coronary atherosclerosis in African American and white patients with acute chest pain: characterization with coronary CT angiography.

  Authors: John W Nance, Fabian Bamberg, U Joseph Schoepf, Doo Kyoung Kang, J Michael Barraza, Joseph A Abro, Gorka Bastarrika, Gary F Headden, Philip Costello, Christian Thilo

  Radiology. 06/2011; 260(2):373-80.

  To use coronary computed tomographic (CT) angiography to compare the prevalence, extent, and composition of coronary atherosclerotic lesions in African American and white patients with acute chestTo use coronary computed tomographic (CT) angiography to compare the prevalence, extent, and composition of coronary atherosclerotic lesions in African American and white patients with acute chest pain. The institutional review board waived the requirement for informed consent for this retrospective, HIPAA-compliant matched-cohort study. The authors analyzed the CT angiographic data of 301 patients (150 consecutive African American patients; 151 white control patients; mean age, 55 years ± 11 [standard deviation]; 33% male) with acute chest pain. Each coronary artery segment was evaluated for presence of atherosclerotic plaque, plaque composition (calcified, noncalcified, or mixed), and stenosis. In addition, the noncalcified plaque volume was quantified by using a threshold-based automated algorithm. The presence and extent of atherosclerotic plaque were compared between the groups by using univariate and multivariate regression analyses. While there was no significant difference between the African American and white patients with respect to presence of any plaque (118 [79%] of 150 vs 112 [74%] of 151 patients, respectively; P = .36) or presence of stenosis (26 [17%] vs 37 [24%] patients, respectively; P = .13), the African American patients had a significantly higher prevalence (96 [64%] vs 62 [41%] patients, respectively; P < .001) and volume (median volume, 2.2 vs 1.4 mL, respectively; P < .001) of noncalcified plaque, independent of diabetes and other cardiovascular risk factors (odds ratio, 2.45; 95% confidence interval: 1.52, 4.04). In contrast, the African American patients had a lower prevalence of calcified plaque (39 [26%] vs 68 [45%] white patients, P = .001). Study results suggest that atherosclerotic plaque burden and composition, as measured by using coronary CT angiography, differ between African American and white patients, with relatively more noncalcified disease in African Americans and more calcified disease in white individuals. Further research is warranted to determine whether CT plaque characterization can improve cardiac risk prediction in African Americans.

• Cost-effectiveness of substituting dual-energy CT for SPECT in the assessment of myocardial perfusion for the workup of coronary artery disease.

  Authors: Mathias Meyer, John W Nance, U Joseph Schoepf, Antonio Moscariello, Markus Weininger, Garrett W Rowe, Balazs Ruzsics, Doo Kyoung Kang, Salvatore A Chiaramida, Stefan O Schoenberg, Christian Fink, Thomas Henzler

  European journal of radiology. 01/2011;

  PURPOSE: We compared cost-effectiveness and potential lifetime benefits of using dual-energy computed tomography (DECT) for myocardial perfusion assessment instead of single photon emission computedPURPOSE: We compared cost-effectiveness and potential lifetime benefits of using dual-energy computed tomography (DECT) for myocardial perfusion assessment instead of single photon emission computed tomography (SPECT) for the workup of coronary artery disease (CAD). MATERIALS AND METHODS: A decision and simulation model was developed to estimate cost and health effects of using DECT myocardial perfusion imaging instead of SPECT for identifying patients in need of invasive imaging and possible revascularization. The model was based on the performance indices of stress/rest DECT compared with stress/rest SPECT for detecting myocardial perfusion deficits in 50 patients (mean age 61±10 years) with CAD. Stress/rest perfusion and delayed enhancement cardiac MRI served as reference standard. For DECT a reimbursement of US$1700 was assumed but costs of cardiac MRI were not included in the model. All other actual healthcare costs in these patients were derived from MUSC's hospital billing system. RESULTS: Compared with cardiac MRI, DECT (versus SPECT) had 90% (85%) sensitivity and 71% (58%) specificity for identifying patients with obstructive CAD. Compared with the no imaging and no treatment strategy, routine SPECT gained 13.49 quality-adjusted life-years (QALYs) with an incremental cost-effectiveness ratio (ICER) of US$3557 (in 2010) per QALY. In comparison, DECT ICER was lower (US$3.191 per QALY, p=0.0002) and an additional 0.64 QALYs was obtained (total of 14.13 QALYs) if compared with the SPECT strategy as well as the no imaging and no treatment strategy. CONCLUSION: Using DECT as the first-line imaging test for myocardial perfusion for the workup of patients with CAD has the potential to provide gains in QALYs, while lowering costs if compared to routine myocardial perfusion SPECT.

• CT comparison of visual and computerised quantification of coronary stenosis according to plaque composition.

  Authors: Doo Kyoung Kang, Nae Jung Im, Soon Mo Park, Hong Seok Lim

  European radiology. 10/2010; 21(4):712-21.

  To compare the diagnostic performance of computerised quantification with visual assessment for the detection of significant coronary stenosis using MDCT, and to determine the impact of plaqueTo compare the diagnostic performance of computerised quantification with visual assessment for the detection of significant coronary stenosis using MDCT, and to determine the impact of plaque composition on diagnostic procedure. We retrospectively evaluated 1564 coronary segments of 127 patients who underwent 64-slice MDCT and quantitative coronary angiography (QCA). The lesions were analysed with both methods of visual assessment and computerised quantification using an automatic vessel contour detection tool, and the results were compared with the QCA results. Plaques detected with MDCT were classified as calcified, mixed, and non-calcified according to plaque composition. The sensitivity and PPV of visual assessment (computerised quantification) were 95% (86%) and 76% (81%), respectively. Bland-Altman analysis demonstrated a mean difference of -5.2 ± 21.6% for all lesions, 2.2 ± 23.7 for calcified plaques, and -12.0 ± 17.2% for non-calcified plaques. The correlation coefficients and limits of agreement between CTA and QCA were 0.48 and ± 46.5% (0.74 and ± 33.7%) in the lesions with calcified plaques (non-calcified plaques). The computerised quantification decreases the sensitivity due to underestimation of non-calcified plaques compared with visual assessment, and had a poorer correlation and a larger limit of agreement in the lesions with calcified plaque compared with non-calcified plaques.

• Dual-energy computed tomography for integrative imaging of coronary artery disease: principles and clinical applications.

  Authors: Doo Kyoung Kang, U Joseph Schoepf, Gorka Bastarrika, John W Nance, Joseph A Abro, Balazs Ruzsics

  Seminars in ultrasound, CT, and MR. 08/2010; 31(4):276-91.

  The introduction of coronary CT angiography (cCTA) has reinvigorated the debate whether management of patients with suspected coronary artery disease (CAD) should be primarily based on physiological,The introduction of coronary CT angiography (cCTA) has reinvigorated the debate whether management of patients with suspected coronary artery disease (CAD) should be primarily based on physiological, functional versus anatomical testing. Anatomical testing (i.e., cCTA or invasive catheterization) enables direct visualization and grading of coronary artery stenoses but has shortcomings for gauging the hemodynamic significance of lesions for myocardial perfusion. Rest/stress myocardial perfusion imaging (MPI) has been extensively validated for assessing the clinical significance of CAD by demonstrating fixed or reversible perfusion defects but has only limited anatomical information. There is growing evidence that contrast medium enhanced dual-energy cCTA (DECT) has potential for the comprehensive analysis of coronary artery morphology as well as changes in myocardial perfusion. DECT exploits the fact that tissues in the human body and iodine-based contrast media have unique absorption characteristics when penetrated with different X-ray energy levels, which enables mapping the iodine (and thus blood) distribution within the myocardium. The purpose of this communication is to describe the practical application of this technology for the comprehensive diagnosis of ischemic heart disease. We examine recent scientific findings in the context of current pivotal transitions in cardiovascular disease management and demonstrate the potential of cardiac DECT for the integrative assessment of patients with known or suspected CAD within a single CT-based protocol.

• Adenosine-stress dynamic myocardial CT perfusion imaging: initial clinical experience.

  Authors: Gorka Bastarrika, Luis Ramos-Duran, Michael A Rosenblum, Doo Kyoung Kang, Garrett W Rowe, U Joseph Schoepf

  Investigative radiology. 06/2010; 45(6):306-13.

  To evaluate the feasibility of adenosine-stress dynamic myocardial volume perfusion imaging with second generation dual source computed tomography (CT) for the qualitative and quantitative assessmentTo evaluate the feasibility of adenosine-stress dynamic myocardial volume perfusion imaging with second generation dual source computed tomography (CT) for the qualitative and quantitative assessment of myocardial blood flow (MBF) compared with stress perfusion and viability magnetic resonance imaging (MRI). Ten patients (8 male, 2 female, mean age 62.7 +/- 7.1 years) underwent stress/rest perfusion and delayed-enhancement MRI, and a cardiac CT protocol comprising prospectively electrocardiogram -triggered coronary CT angiography, dynamic adenosine-stress myocardial perfusion imaging using a "shuttle" mode, and delayed enhancement acquisitions. Two independent observers visually assessed myocardial perfusion defects. For semi-quantitative evaluation, CT- and MRI-derived myocardial-to-left ventricular upslope indices were compared. Additionally, absolute MBF was quantified based on dynamic perfusion CT and correlated with semi quantitative CT measurements. Myocardial perfusion analysis was performed on a segmental basis. Analysis used paired t tests, Wilcoxon signed-rank test, linear correlation, and Bland-Altman statistics. A total of 149 segments (93.1%) were suitable for analysis. Sensitivity, specificity, positive and negative predictive values for detection of myocardial perfusion defects at CT compared with MRI were 86.1%, 98.2%, 93.9%, and 95.7%, respectively. Semiquantitative analysis of CT data showed significant differences between ischemic and nonischemic myocardium with a signal intensity upslope that was comparable with MRI-derived values (CT: 5.2 +/- 2 SI/s, MRI: 4.8 +/- 2.3 SI/s, P > 0.05). Moderate correlation was observed between absolute CT quantification of MBF and semi-quantitative CT measurements. Mean total dose length product for the entire cardiac CT protocol was 1290.4 +/- 233.3 mGy cm. Adenosine-stress volumetric first pass CT perfusion imaging is feasible and may enable the evaluation of qualitative and semi quantitative parameters of myocardial perfusion in a comparable fashion as MRI.

• CT findings in patients with pericardial effusion: differentiation of malignant and benign disease.

  Authors: Joo Sung Sun, Kyung Joo Park, Doo Kyoung Kang

  AJR. American journal of roentgenology. 06/2010; 194(6):W489-94.

  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 ofThis 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. 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. 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%. 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.

• Reproducibility of CT signs of right ventricular dysfunction in acute pulmonary embolism.

  Authors: Doo Kyoung Kang, Luis Ramos-Duran, U Joseph Schoepf, Andrew M Armstrong, Joseph A Abro, James G Ravenel, Christian Thilo

  AJR. American journal of roentgenology. 06/2010; 194(6):1500-6.

  The purpose of our study was to determine the interobserver reproducibility of CT findings of right ventricular (RV) dysfunction in pulmonary embolism (PE). Two experienced observers independentlyThe purpose of our study was to determine the interobserver reproducibility of CT findings of right ventricular (RV) dysfunction in pulmonary embolism (PE). Two experienced observers independently and retrospectively evaluated pulmonary CT angiography (CTA) studies of 50 patients with acute PE for the following signs: bowing of the interventricular septum, inferior vena cava (IVC) contrast medium reflux, RV diameter (RVD)/left ventricular diameter (LVD) ratio on axial sections and four-chamber (4-CH) views, and RV volume (RVV)/left ventricular volume (LVV) ratio. Analysis used kappa statistics, Spearman's rank correlation, and Bland-Altman statistics. The two observers had fair to moderate agreement (kappa = 0.32-0.44) for septal bowing and moderate to good agreement (kappa = 0.57-0.68) for diagnosing IVC reflux. The Spearman's rank correlation coefficients for RVD(axial)/LVD(axial) ratio and RVD(4-CH)/LVD(4-CH) ratio between the two observers were 0.88 (p < 0.001) and 0.85 (p < 0.001), respectively. On Bland-Altman analysis, the mean differences for RVD(axial)/LVD(axial) ratio and RVD(4-CH)/LVD(4-CH) ratio were 0.014 (+/- 0.195) and 0.001 (+/- 0.242), respectively. The correlation coefficient for RVV/LVV ratio was 0.93 (p < 0.001), and the mean difference was 0.033 (+/- 0.229). Considerable differences exist in the interobserver reproducibility of CT findings of RV dysfunction on pulmonary CTA in patients with acute PE. Cardiac chamber measurements are more reproducible than septal bowing and IVC reflux. Volumetric determination of the RVV/LVV ratio is the least user dependent and most reproducible.

• Comparison of 64-slice multidetector computed tomography with spectral analysis of intravascular ultrasound backscatter signals for characterizations of noncalcified coronary arterial plaques.

  Authors: Byoung-Joo Choi, Doo Kyoung Kang, Seung-Jea Tahk, So-Yeon Choi, Myeong-Ho Yoon, Hong-Seok Lim, Soo-Jin Kang, Hyoung-Mo Yang, Jin-Sun Park, Mingri Zheng, Gyo-Seung Hwang, Joon-Han Shin

  The American journal of cardiology. 10/2008; 102(8):988-93.

  In vivo identification of plaque composition may allow the detection of vulnerable plaques before rupture. However, the clinical relevance of multidetector computed tomography (MDCT) inIn vivo identification of plaque composition may allow the detection of vulnerable plaques before rupture. However, the clinical relevance of multidetector computed tomography (MDCT) in characterizing coronary plaques is currently a subject of debate. We compared 64-slice MDCT with virtual histology to investigate the potential role of 64-slice MDCT in the differentiation of composition of noncalcified coronary plaques. Fifty-nine consecutive patients (stable/unstable angina 34/21) were enrolled. Mean computed tomographic (CT) density (Hounsfield units) of noncalcified coronary plaques (n = 80) was compared with a relative volume of each plaque component (fibrous, fibrofatty, calcium, and necrotic core) analyzed by virtual histology. Mean heart rate during MDCT was 58 +/- 9 beats/min. There was a negative correlation between mean CT density and the necrotic core (r = -0.539, p <0.001) and a positive correlation between mean CT density and the fibrotic tissue component (r = 0.571, p <0.001). Mean CT density of the plaques with a <10% necrotic core was significantly higher than that of a >/=10% necrotic core (93.1 +/- 37.5 vs 41.3 +/- 26.4 HU, p <0.001). However, overlapping of mean CT densities between plaques with a <10% necrotic core and those with a >/=10% necrotic core was found. In conclusion, mean CT density of noncalcified coronary plaques measured by 64-slice MDCT may depend on the relative volumes of the necrotic core and fibrotic component. Sixty-four-slice MDCT may have the potential for determining composition of noncalcified coronary plaques, which needs further studies for clinical application.

• Correlation of whole-breast vascularity with ipsilateral breast cancers using contrast-enhanced MDCT.

  Authors: Doo Kyoung Kang, Eun Jin Kim, Ho Sung Kim, Joo Sung Sun, Yong Sik Jung

  AJR. American journal of roentgenology. 03/2008; 190(2):496-504.

  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 breastOBJECTIVE: 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.

• Sonographic differentiation of benign and malignant papillary lesions of the breast.

  Authors: Tae Hee Kim, Doo Kyoung Kang, Sun Yong Kim, Eun Ju Lee, Yong Sik Jung, Hyunee Yim

  Journal of ultrasound in medicine : official journal of the American Institute of Ultrasound in Medicine. 01/2008; 27(1):75-82.

  OBJECTIVE: The purpose of this study was to evaluate sonographic findings of breast papillary lesions and the effectiveness of the American College Radiology Breast Imaging Reporting and Data SystemOBJECTIVE: The purpose of this study was to evaluate sonographic findings of breast papillary lesions and the effectiveness of the American College Radiology Breast Imaging Reporting and Data System sonographic assessment system for differentiation of benign and malignant papillary lesions. METHODS: We retrospectively reviewed breast sonographic findings of 46 surgically proven benign papillomas and 22 papillary carcinomas. All sonographic images of patients were interpreted by 2 radiologists. Sonographic findings were analyzed according to the Breast Imaging Reporting and Data System classification. RESULTS: The shape of the lesion was round or oval in 33 benign lesions (71.7%) and 13 papillary carcinomas (61.9%). As for the margin, a circumscribed margin was found in 31 benign papillomas (67.4%) and 12 malignant lesions (57.1%). Differences in the predominant shape and margin between the 2 groups were not statistically significant (P > .05). Fourteen benign papillomas (30.5%) and 12 papillary carcinomas (57.1%) showed a complex echo pattern. It was more frequently observed in malignant lesions; however, it was not statistically significant (P = .09). A nonparallel orientation, an echogenic halo, posterior acoustic enhancement, and associated microcalcification were more frequently found in malignant than in benign lesions (P < .05). When the presence of any suspicious sonographic feature (nonparallel orientation, echogenic halo, posterior enhancement, or calcification) was considered to indicate malignancy, interpretation of the sonographic features gave sensitivity of 85.7%, specificity of 64.9%, a positive predictive value of 47.4%, and a negative predictive value of 92.5% for detection of malignant papillary lesions. The only differential finding between noninvasive and invasive papillary cancers was a circumscribed margin (P < .05). CONCLUSIONS: Sonographic features more specific to malignancy include a nonparallel orientation, an echogenic halo, posterior acoustic enhancement, and associated microcalcification.

• Diagnosis of the intraductal component of invasive breast cancer: assessment with mammography and sonography.

  Authors: Doo Kyoung Kang, Gyeong Sik Jeon, Hyunee Yim, Yong Sik Jung

  Journal of ultrasound in medicine : official journal of the American Institute of Ultrasound in Medicine. 12/2007; 26(11):1587-600.

  OBJECTIVE: The aim of this study was to investigate mammographic and sonographic features and their sensitivities for depiction of the intraductal component associated with invasive ductal carcinomaOBJECTIVE: The aim of this study was to investigate mammographic and sonographic features and their sensitivities for depiction of the intraductal component associated with invasive ductal carcinoma (IDC). METHODS: During a 1-year period, 132 patients with IDC underwent surgical treatment. All patients underwent mammography and high-resolution sonography, and the findings were reported according to the American College of Radiology's Breast Imaging Reporting and Data System lexicon. Tumors were classified as "pure IDC" and "IDC with an intraductal component" by histopathologic evaluation. We compared mammographic and sonographic features between the above 2 groups and attempted to correlate them with histopathologic findings. We also investigated separate and combined sensitivities, specificities, and accuracies of both mammography and breast sonography for showing intraductal components. Finally, imaging measurements were compared with pathologic measurements. RESULTS: One hundred four (79%) of the 132 IDCs contained an intraductal component. Patients with IDC with an intraductal component showed calcifications on mammography and showed an echogenic halo, duct dilatation, calcifications, and increased vascularity in surrounding tissue on sonography more frequently than patients with pure IDC. The sensitivities of mammography, sonography, and their combined assessment for detection of an intraductal component were 55%, 80%, and 86%, respectively. The combined assessment (r = 0.90) measured the extent of the tumor more accurately than mammography (r = 0.71) or sonography (r = 0.79) separately. CONCLUSIONS: Combined assessment with mammography and sonography offers more accurate information for the presence of an intraductal component and the extent of a tumor than each separate assessment.

• Clinical application of multidetector row computed tomography in patient with breast cancer.

  Authors: Doo Kyoung Kang, Min Ji Kim, Yong Sik Jung, Hyunee Yim

  Journal of computer assisted tomography. 32(4):583-98.

  Although multidetector row computed tomography is not the primary method of evaluating breast cancer, it could be performed as an excellent alternative, especially in the presence of magneticAlthough multidetector row computed tomography is not the primary method of evaluating breast cancer, it could be performed as an excellent alternative, especially in the presence of magnetic resonance contraindications. Moreover, computed tomography can still have an important role in evaluation of nodal status, thoracic invasion, and distant metastasis because of the large area covered in a single examination. Our experience together with literature indicates that multidetector row computed tomography is a powerful supplementary method for evaluation of patients with breast cancer.

• High-temporal resolution dual-energy computed tomography of the heart using a novel hybrid image reconstruction algorithm: initial experience.

  Authors: John William Nance, Gorka Bastarrika, Doo Kyoung Kang, Balazs Ruzsics, Sebastian Vogt, Bernhard Schmidt, Rainer Raupach, Thomas G Flohr, U Joseph Schoepf

  Journal of computer assisted tomography. 35(1):119-25.

  Dual-energy computed tomography (DECT) has been proposed for the comprehensive assessment of coronary artery stenosis and myocardial perfusion yet traditionally required reducing the temporalDual-energy computed tomography (DECT) has been proposed for the comprehensive assessment of coronary artery stenosis and myocardial perfusion yet traditionally required reducing the temporal resolution of cardiac studies. We evaluated a reconstruction algorithm that preserves high temporal resolution at cardiac DECT. Twelve consecutive patients (3 women; mean [SD] age, 64 [10] years) with an abnormal single photon emission CT result underwent invasive coronary angiography and cardiac DECT. Dual-energy CT studies were reconstructed using the standard algorithm with 165-millisecond temporal resolution and a hybrid algorithm providing 83-millisecond temporal resolution. These studies were rated for coronary image quality and motion artifacts and compared with invasive coronary angiographic studies. One hundred sixty-eight coronary artery segments (82%) were evaluated. The standard 165-millisecond reconstruction provided 95% diagnostic segments compared with 100% using the 83-millisecond hybrid reconstruction. Image quality was rated significantly (P < 0.05) better with hybrid reconstruction and had 91.4% sensitivity, 94.7% specificity, 82.1% positive predictive value, and 97.7% negative predictive value for detecting significant stenosis versus 85.7%, 93.2%, 76.9%, and 96.1% with standard reconstruction, respectively. Hybrid image reconstruction mitigates the former limitations in temporal resolution of cardiac DECT.

• Adenosine-stress dynamic myocardial volume perfusion imaging with second generation dual-source computed tomography: Concepts and first experiences.

  Authors: Gorka Bastarrika, Luis Ramos-Duran, U Joseph Schoepf, Michael A Rosenblum, Joseph A Abro, Robin L Brothers, José L Zubieta, Salvatore A Chiaramida, Doo Kyoung Kang

  Journal of cardiovascular computed tomography. 4(2):127-35.

  Recent research suggests that multidetector-row CT may have potential as a standalone modality for integrative imaging of coronary heart disease, including the assessment of the myocardial bloodRecent research suggests that multidetector-row CT may have potential as a standalone modality for integrative imaging of coronary heart disease, including the assessment of the myocardial blood supply. However, the technical prerequisites for volumetric, time-resolved imaging of the passage of a contrast medium bolus through the myocardium have only been met with latest generation wide-detector CT scanners. Second-generation dual-source CT enables performing electrocardiographic (ECG)-synchronized dynamic myocardial perfusion imaging by a dedicated "shuttle" mode. With this acquisition mode, image data can be acquired during contrast medium infusion at 2 alternating table positions with the table shuttling back and forth between the 2 positions covering a 73-mm anatomic volume. We applied this acquisition technique for detecting differences in perfusion patterns between healthy and diseased myocardium and for quantifying myocardial blood flow under adenosine stress in 3 patients with coronary heart disease. According to our initial experience, the addition of adenosine stress volumetric dynamic CT perfusion to a cardiac CT protocol comprising coronary artery calcium quantification, prospectively ECG-triggered coronary CT angiography, and delayed acquisition appears promising for the comprehensive assessment of coronary artery luminal integrity, cardiac function, perfusion, and viability with a single modality.