Human Medical Imaging and Intervention Center

Seoul, South Korea

Human Medical Imaging and Intervention Center

Seoul, South Korea
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Hong M.J.,Gachon University | Na D.G.,Human Medical Imaging and Intervention Center | Baek J.H.,University of Ulsan | Sung J.Y.,Daerim St Marys Hospital | Kim J.-H.,Seoul National University
Thyroid | Year: 2017

Background: The malignancy risk of a cytology diagnosis may depend on the ultrasonography (US) patterns of thyroid nodules, and management should be determined by the combined malignancy risk of fine-needle aspiration (FNA) cytology and US patterns. This study was performed to develop a clinically applicable cytology-ultrasonography (CU) scoring system for malignancy risk stratification based on FNA cytology and US patterns, according to the Korean-Thyroid Imaging Reporting and Data System (K-TIRADS). Methods: This retrospective Institutional Review Board-approved study included 1651 thyroid nodules (≥1 cm) with final diagnoses. The malignancy risk was assessed of the combined results of FNA cytology and the K-TIRADS for the development of the CU system. The interaction between FNA cytology and US pattern (K-TIRADS) in the malignancy risk of nodules was investigated by using a binominal test. Results: The malignancy risk of nodules could be stratified into four CU scores (very low risk, <3%; low risk, ≥3%, <30%; high risk, ≥30%, <90%; very high risk, ≥90%). In nodules with non-diagnostic, benign, and atypia of undetermined significance/follicular lesion of undetermined significance cytology results, low-suspicion US pattern (K-TIRADS 3) significantly decreased the malignancy risk of nodules (p = 0.003, 0.013, and 0.027, respectively), and a high-suspicion US pattern (K-TIRADS 5) significantly increased the malignancy risk of nodules (p ≤ 0.001). A Bethesda 1 or 4 cytology result did not significantly change the malignancy risk of any K-TIRADS (p ≥ 0.518 and p ≥ 0.137, respectively). A Bethesda 2 cytology result decreased and a Bethesda 5 or 6 cytology result increased the malignancy risk of K-TIRADS 3, 4, and 5 (p ≤ 0.001). A Bethesda 3 cytology result increased the malignancy risk of K-TIRADS 3 and 4 (p < 0.001 and p = 0.024, respectively). Conclusion: The malignancy risk of thyroid nodules can be stratified by the CU risk-stratification system, based on FNA cytology and the K-TIRADS. The proposed CU scoring system may be helpful in the management of thyroid nodules after FNA. © Copyright 2017, Mary Ann Liebert, Inc. 2017.

PubMed | Ajou University, Soonchunhyang University, University of Ulsan, Catholic University of Korea and 11 more.
Type: Review | Journal: Korean journal of radiology | Year: 2017

Core needle biopsy (CNB) has been suggested as a complementary diagnostic method to fine-needle aspiration in patients with thyroid nodules. Many recent CNB studies have suggested a more advanced role for CNB, but there are still no guidelines on its use. Therefore, the Task Force Committee of the Korean Society of Thyroid Radiology has developed the present consensus statement and recommendations for the role of CNB in the diagnosis of thyroid nodules. These recommendations are based on evidence from the current literature and expert consensus.

Seo H.S.,Korea University | Kim J.-H.,Seoul National University | Lee D.H.,Seoul Medical Center | Lee Y.H.,Korea University | And 4 more authors.
American Journal of Neuroradiology | Year: 2010

BACKGROUND AND PURPOSE: Most intramedullary astrocytomas have been known to exhibit at least some enhancement on MR imaging regardless of cell type or tumor grade. The purpose of this study was to evaluate the incidence of nonenhancing intramedullary astrocytomas through a retrospective study within our institutions and a systematic review of the medical literature. MATERIALS AND METHODS: A total of 19 consecutive patients (male to female ratio, 11:8; mean age, 27.84 ± 19.0 years) with primary intramedullary astrocytomas (3 WHO grade I, 13 WHO grade II, 3 WHO grade III) who underwent preoperative MR imaging with contrast enhancement were included in this retrospective study from 4 institutions. The tumor-enhancement patterns were classified into the following categories: 1) no enhancement, 2) focal nodular enhancement, 3) patchy enhancement, 4) inhomogeneous diffuse enhancement, and 5) homogeneous diffuse enhancement. Seven articles including MR imaging enhancement studies of intramedullary astrocytomas were eligible for literature review. RESULTS: In the retrospective study, 6 astrocytomas (32%), including 2 anaplastic astrocytomas, did not enhance at all. Focal nodular enhancement was identified in 5 astrocytomas (26%); patchy enhancement, in 3 (16%); inhomogeneous diffuse enhancement, in 5 (26%); and homogeneous diffuse enhancement, in none. In the literature review, the frequency of nonenhancing intramedullary astrocytomas was 14 of 76 (18%), including 2 anaplastic astrocytomas. CONCLUSIONS: Nonenhancing intramedullary astrocytomas are not uncommon and comprise between 20% and 30% of intramedullary astrocytomas. Therefore, astrocytoma must remain in the differential diagnosis of nonenhancing intramedullary lesions, particularly if the lesion demonstrates a prominent mass effect or cord expansion.

Baek J.H.,University of Ulsan | Baek J.H.,Daerim St Marys Hospital | Lee J.H.,University of Ulsan | Sung J.Y.,Daerim St Marys Hospital | And 13 more authors.
Radiology | Year: 2012

Purpose: To evaluate clinical aspects and imaging features of complications encountered in the treatment of benign thyroid nodules with radiofrequency (RF) ablation. Materials and Methods: Institutional review board approval was obtained for this retrospective study, and informed consent was waived. From June 2002 to September 2009, 1459 patients underwent RF ablation of 1543 thyroid nodules with an RF system with internally cooled electrodes at 13 thyroid centers, which were members of Korean Society of Thyroid Radiology. Numbers and types of major and minor complications were assessed. Results: The authors observed 48 complications (3.3%), 20 major and 28 minor. The major complications were voice changes (n = 15), brachial plexus injury (n = 1), tumor rupture (n = 3), and permanent hypothyroidism (n = 1). The minor complications were hematoma (n = 15), skin burn (n = 4), and vomiting (n = 9). All patients recovered spontaneously except for one with permanent hypothyroidism and one who underwent surgery. Conclusion: Although the complication rate of RF ablation is low, various complications may occur; comprehension of complications and suggested technical tips may prevent complications or properly manage those that occur. © RSNA, 2011.

Na D.G.,Human Medical Imaging and Intervention Center | Kim J.-H.,Seoul National University | Sung J.Y.,Daerim St Marys Hospital | Baek J.H.,University of Ulsan | And 3 more authors.
Thyroid | Year: 2012

Background: Thyroid nodules with fine-needle aspiration (FNA) readings of nondiagnostic or atypia of undetermined significance (AUS), also referred to as follicular lesion of undetermined significance (FLUS) are problematic for their optimal management. The usefulness of performing a core-needle biopsy (CNB) to clarify whether these nodules are benign or malignant has not been established. The purpose of the present study was to determine whether CNB provides better diagnostic information than repeat FNA (rFNA) in thyroid nodules having nondiagnostic or AUS/FLUS readings. Materials and Methods: The Bethesda System for Reporting Thyroid Cytopathology was used for FNA readings and for CNB readings. The study included 225 thyroid nodules from 220 consecutive patients who previously had nondiagnostic (Group N-DIAG, n=64) or AUS/FLUS (Group AF, n=161) FNA readings. All patients simultaneously underwent rFNA and CNB of each nodule. The nondiagnostic and AUS/FLUS readings by rFNA and by CNB were compared. The diagnostic sensitivities of rFNA and CNB for malignancy in thyroid nodules were also assessed. Statistical analysis was performed using a McNemar's test. Results: In N-DIAG Group, the nondiagnostic readings for the CNBs were lower than that those for rFNAs (1.6% vs. 28.1%, p<0.001). In the AF Group, the AUS/FLUS readings for the CNBs were lower than those for the rFNAs (23.6% vs. 39.8%, p<0.001). The inconclusive diagnoses (nondiagnostic or AUS/FLUS) for the CNBs were lower than those for the rFNAs in Group N-DIAG (12.5% vs. 45.3%, p<0.001) and Group AF (26.7% vs. 49.1%, p<0.001). The sensitivity of CNB for thyroid malignancy was higher than that of rFNA in Group N-DIAG (100% vs. 71.4%, p=0.125) and Group AF (78.5% vs. 55.4%, p<0.001). Conclusion: After patients have had one FNA of a thyroid nodule yielding inconclusive diagnostic results (nondiagnostic or AUS/FLUS), CNB is more useful than rFNA for reducing the frequency of inconclusive diagnostic results. CNB will improve the diagnostic performance for malignancy more than rFNA in thyroid nodules that on the first FNA had nondiagnostic or AUS/FLUS readings. © Copyright 2012, Mary Ann Liebert, Inc.

Baek J.H.,University of Ulsan | Lee J.H.,University of Ulsan | Valcavi R.,Endocrinology Division and Thyroid Disease Center | Pacella C.M.,Interventional Imaging | And 2 more authors.
Korean Journal of Radiology | Year: 2011

Although ethanol ablation has been successfully used to treat cystic thyroid nodules, this procedure is less effective when the thyroid nodules are solid. Radiofrequency (RF) ablation, a newer procedure used to treat malignant liver tumors, has been valuable in the treatment of benign thyroid nodules regardless of the extent of the solid component. This article reviews the basic physics, techniques, applications, results, and complications of thyroid RF ablation, in comparison to laser ablation.

Kim S.A.,Human Medical Imaging and Intervention Center | Chang J.M.,Seoul National University | Cho N.,Seoul National University | Yi A.,Seoul National University | Moon W.K.,Seoul National University
Korean Journal of Radiology | Year: 2015

Objective: To compare the diagnostic performance of digital breast tomosynthesis (DBT) and conventional breast ultrasound (US) to characterize breast lesions as benign or malignant. Materials and Methods: A total of 332 women, presenting for screening examinations or for breast biopsy between March and June 2012 were recruited to undergo digital mammography (DM), DBT, and breast US examination. Among them, 113 patients with 119 breast lesions depicted on DM were finally included. Three blinded radiologists performed an enriched reader study and reviewed the DBT and US images. Each reader analyzed the lesions in random order, assigned Breast Imaging Reporting and Data System (BI-RADS) descriptors, rated the images for the likelihood of malignancy (%) and made a BI-RADS final assessment. Diagnostic accuracy, as assessed by the area under the receiver operating characteristic curve, sensitivity, and specificity of DBT and US were compared. Results: Among the 119 breast lesions depicted on DM, 75 were malignant and the remaining 44 were benign. The average diagnostic performance for characterizing breast lesions as benign or malignant in terms of area under the curve was 0.899 for DBT and 0.914 for US (p = 0.394). Mean sensitivity (97.3% vs. 98.7%, p = 0.508) and specificity (44.7% vs. 39.4%, p = 0.360) were also not significantly different. Conclusion: Digital breast tomosynthesis may provide similar reader lesion characterization performance to that of US for breast lesions depicted on DM. © 2015 The Korean Society of Radiology.

Seo H.,Seoul National University | Na D.G.,Human Medical Imaging and Intervention Center | Kim J.-H.,Seoul National University | Kim K.W.,Seoul National University | Yoon J.W.,Seoul National University
European Radiology | Year: 2015

Objectives: The purpose of this study was to stratify the malignancy risk of US features, with an emphasis on nodule echogenicity. Methods: A total of 1,058 nodules of 824 consecutive patients (236 malignant and 822 benign) were included in this study. Malignancy risk of each nodule was analyzed according to US features, with an emphasis on nodule echogenecity, and was stratified into 4-tier categories. Results: In multivariate analysis, isoechogenicity, indistinct margin, non-solid internal content, and parallel orientation were predictive of benign nodules (P < 0.002), while hypoechogenicity, marked hypoechogenicity, spiculated/microlobulated margin, solid content, nonparallel orientation (taller than wide), microcalcification, and macrocalcification were predictive of malignancy (P ≤ 0.037). Although the presence of US features associated with malignancy was significantly predictive of malignancy in hypoechoic and markedly hypoechoic nodules (P ≤ 0.004), it was not associated with malignancy in isoechoic or hyperechoic nodules. Thyroid nodules could be stratified into four categories according to the malignancy risk: benign (risk 0 %), probably benign (risk ≤ 5 %), indeterminate (risk > 5 and < 50 %), and suspicion of malignancy (risk > 50 %). Conclusions: The US-based four-tier categorization system will be useful for predicting the risk of malignancy and decisions regarding FNA for thyroid nodules. Key Points: • No US feature was predictive of malignancy in isoechoic nodules. • Isoechoic nodules without calcification can be included in the probably benign category. • We suggest a four-tier categorization stratified primarily by nodule echogenecity. • The four-tier categorization of thyroid nodules will be useful for FNA decisions. © 2015, European Society of Radiology.

Na D.G.,Human Medical Imaging and Intervention Center | Lee J.H.,University of Ulsan | Kim S.M.,University of Ulsan | Lim H.K.,University of Ulsan | Baek J.H.,University of Ulsan
Journal of Vascular and Interventional Radiology | Year: 2011

Purpose: To modify the direction of radiofrequency (RF) ablation and to find optimal technical parameters using a partially insulated electrode. Materials and Methods: The authors developed a unidirectional ablation electrode (UAE) by partial insulation of a 1-cm active electrode tip. Each electrode produced 60 ablation zones using insulation of the active tip (270°, group A; 180°, group B; and noninsulated, group C). In each group, six subgroups were created by combining the RF powers (5 W, 10 W, and 20 W) and ablation duration (6 minutes and 12 minutes). Technical success was determined when a half-moonshaped ablation zone was achieved. The volumes of the technical success zone (Vs) and the technical failure zone (Vf) were measured. Results: Technical success was achieved in all 10 cases using a 270° insulated electrode with a 5-W/6-minute parameter. The mean Vs of group A was significantly smaller than the mean Vs of either group B or group C (P = .003 and P < .001). The mean Vf of group A was significantly smaller than the mean Vf of group B, which was smaller than that of group C (P < .001). Conclusions: A UAE with a partially insulated tip can modify the ablation zone, especially when using 270° insulation with a 5-W/6-minute parameter. © 2011 SIR.

An Y.Y.,Catholic University of Korea | Kim S.H.,Catholic University of Korea | Kang B.J.,Catholic University of Korea | Lee J.H.,Human Medical Imaging and Intervention Center
World Journal of Surgical Oncology | Year: 2013

Background: Magnetic resonance imaging (MRI)-guided vacuum-assisted biopsy is the technique of choice for lesions that are visible only with breast MRI. The purpose of this study was to report our clinical experience with MRI-guided vacuum-assisted biopsy in Korean women.Methods: A total of 13 patients with 15 lesions for MRI-guided vacuum-assisted biopsy were prospectively entered into this study between September 2009 and November 2011. Biopsy samples were obtained in a 3-T magnet using a 9-guage MRI-compatible vacuum-assisted biopsy device. We evaluated clinical indications for biopsy, lesion characteristics on prebiopsy MRI, pathologic results, and postbiopsy complication status.Results: The clinical indications for MRI-guided vacuum-assisted biopsy were as follows: abnormalities in patients with interstitial mammoplasty on screening MRI (n = 10); preoperative evaluation of patients with a recently diagnosed cancer (n = 3); and suspicious recurrence on follow-up MRI after cancer surgery (n = 1) or chemotherapy (n = 1). All lesions have morphologic features suspicious or highly suggestive of malignancy by the American College of Radiology Breast Imaging Reporting and Data System category of MRI (C4a = 12, C4b = 2, C5 = 1). In two of the 15 lesions (13.3%, <6 mm), MRI-guided 9-gauge vacuum-assisted breast biopsy was deferred due to nonvisualization of the MRI findings that led to biopsy and the lesions were stable or disappeared on follow up so were considered benign. Of 13 biopsied lesions, pathology revealed four malignancies (4/13, 30.8%; mean size 15.5 mm) and nine benign lesions (9/13, 69.2%; size 14.2 mm). Immediate postprocedural hematoma (mean size 23.5 mm) was observed in eight out of 13 patients (61.5%) and was controlled conservatively.Conclusions: Our initial experience of MRI-guided vacuum-assisted biopsy showed a success rate of 86.7% and a cancer diagnosis rate of 30.8%, which was quite satisfactory. MRI-guided vacuum-assisted breast biopsy is a safe and effective tool for the workup of suspicious lesions seen on breast MRI alone without major complication. This biopsy may contribute to the early diagnosis of breast cancer in interstitial mammoplasty patients in Korea. © 2013 An et al.; licensee BioMed Central Ltd.

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