Neuroradiology(TH) Sep 10, Thu

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1 SS 37 NR(NI)- 7:40 Central retinal artery occlusion: the value as warning sign of carotid artery atherosclerosis Se Jeong Jeon, See-Sung Choi, Dea-Won Kim, Yun-Sik Yang Wonkwang University College of Medicine, Korea. PURPOSE: Central retinal artery occlusion (CRAO) is a rare disease with poor visual prognosis. Atherosclerosis is implicated as the inciting event in most cases and the pathophysiology of CRAO is similar that cerebral infarction. Unfortunately there is no proved treatment for CRAO. So, we reviewed the patients with CRAO and evaluated clinical effectiveness of local intra-arterial (IA) thrombolysis and the rate of accompanying carotid atherosclerosis as a cause of CRAO. MATERIALS AND METHODS: A total 34 patients with CRAO were enrolled in this retrospective study between 2009 and 204. Thirty patients underwent local IA thrombolysis, 4 were excluded due to time window and inaccessible carotid lesion. The patients were divided into two groups as follow: Group (treated within 24 hours), Group 2 (treated after 24 hours). Thrombolysis was performed with Urokinase with/without nimodipine. We evaluated carotid lesion by CTA or DSA, visual acuity (VA) before and after treatment, and VA improvement evaluated by ophthalmologist. RESULTS: In group (8/34 patients), 3 patients (6.7%) had full recovery, 5 (27.8%) had partial recovery and 6 (55.8) were not recovered. All patients of group 2 were not recovered. There was (3.3%) periprocedural complication. Among 34 patients, patients (32.3) had carotid lesion which was same side of ophthalmologic symptom. CONCLUSION: Although, the efficacy of intra-arterial thrombolysis for the treatment of CRAO needs to be further evaluated in a controlled trial, we suggest that ophthalmic artery thrombolysis may improve visual acuity of patients who are treated within 24 hours after the onset of symptoms. Also, CRAOs are related to carotid lesion more than we are expected. Therefore, CRAO should be managed like ischemic stroke. SS 37 NR(NI)-2 7:50 Low dose angiographic protocol: effect on patient radiation dose reduction in diagnostic and interventional procedures for intracranial aneurysm Joonsung Choi, Bum-soo Kim, Jihye Song, Yong-Sam Shin, Yon-Kwon Ihn 2 The Catholic University of Korea, Seoul St. Mary s Hospital, 2 The Catholic University of Korea, St. Vincent s Hospital, Korea. bkim.neurorad@gmail.com PURPOSE: To describe effect of low dose angiography protocol on reduction of patient radiation dose in diagnostic and interventional procedures for intracranial aneurysms. MATERIALS AND METHODS: Retrospective analysis of radiation dose area product (DAP) in Gy-cm 2 and air kerma (AK) in Gy for 046 diagnostic and 37 therapeutic Neuroradiology(TH) 349 procedures for intracranial aneurysms in 37 patients (M:F = 338:799; median age, 56 years; range, 3 88 years) between January 202 and June 204 was performed. Since April 203, low dose angiographic protocol was applied (from 3.6 Gy/f to.8 Gy/f). DAP and AK were statistically compared in groups before (group ) and after (group 2) application of low dose protocol. RESULTS: For diagnostic procedure, mean DAP and AK were Gy-cm 2 and Gy in group and Gy-cm 2 and in group 2 (4.8% and 40% reduction for DAP and AK respectively). For therapeutic procedure, mean DAP and AK were Gy-cm 2 and Gy in Group and Gy-cm 2 and Gy in group 2 (39.7% and 0% reduction for DAP and AK respectively). CONCLUSION: Application of low dose angiography protocol has significantly decreased DAP and AK in both diagnostic and therapeutic procedures in patients with intracranial aneurysm. Neuroradiology(TH) 08:00-09:30 Grand Ballroom 04 Thyroid imaging and intervention Chairperson(s) Jeong-Ah Kim Gangnam Severance Hospital, Korea Yoonjung Choi Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Korea SS 02 NR(TH)-0 08:00 Comparison of computed tomography features between follicular neoplasm and nodular hyperplasia Kwanghwi Lee, Dong Wook Kim 2, Ji Hwa Ryu, Hye Jin Baek Inje University Haeundae Paik Hospital, 2 Inje University Busan Paik Hospital, Korea. dwultra@lycos.co.kr PURPOSE: No previous studies have compared the computed tomography (CT) characteristics of the thyroid nodules which were diagnosed as Bethesda IV on cytology. This study aimed to compare CT features of follicular neoplasm (FN) and nodular hyperplasia (NH) and to find specific CT features that distinguish FN from NH. MATERIALS AND METHODS: In 22 patients who underwent preoperative neck CT and thyroid surgery, 59 FNs and 65 NHs were included. In each case, nonenhanced and contrast-enhanced CT images were obtained, and a single radiologist retrospectively analyzed CT images, including degree and pattern of attenuation, nodular configuration, margin, shape, pattern of calcification, degree and pattern of nodular enhancement, and CT halo sign. RESULTS: In univariate analysis, iso-attenuation, intraglandular configuration, smooth margin, ovoid shape, decreased enhancement, and absence of CT halo sign were more frequently revealed in NH (p < 0.05), whereas Neuroradiology(TH) Sep 0, Thu

2 Neuroradiology(TH) Sep 0, Thu 350 KCR 205 low attenuation, expansile configuration, lobulated margin, taller-than-wide shape, increased enhancement, and presence of CT halo sign were more frequently revealed in FN (p < 0.05). The multivariate analysis revealed significant difference between FN and NH in configuration (OR: 2.73, ), degree of enhancement (OR: 2.4, ), and presence of CT halo sign (OR: 7.97, ) (p < 0.05). CONCLUSION: Neck CT may be helpful for distinguishing FN from NH in case of thyroid nodule with Besthesda IV on cytology. SS 02 NR(TH)-02 08:0 Value of early phase contrast-enhanced CT in detecting metastatic lymphadenopathy in papillary thyroid carcinoma Kai Lun Cheng, Jeong Hyun Lee 2, Ji Eun Park 2, Young Jun Choi 2, Jung Hwan Baek 2 Chung Shan Medical University Hospital, Taiwan, 2 Asan Medical Center, Korea. jeonghlee@amc.seoul.kr PURPOSE: Protocols of contrast-enhanced CT (CECT) in papillary thyroid cancer (PTC) patients are varied and yet optimized. Our aim was to explore the best method for CECT for indentifying metastatic lymphadenopathy in PTC patients. MATERIALS AND METHODS: Single phase CECT was obtained either with 25, 35, and 70 seconds delay in 32 PTC patients with 327 pathologically proven lymph nodes. Quantitative parameters of Hounsfield unit (HU) included the enhancement value and normalized value with internal jugular vein, carotid artery, and paraspinal muscle. Receiver operating characteristic analysis was applied for the optimal cutoff value for identifying metastatic lymphadenopathy. RESULTS: Significant differences were observed in the enhancement value as well as the normalized value between the benign and metastatic lymphadenopathy in all 3 phases (all ps < 0.00). The value difference between the benign and metastasis was largest in 25s (58.22 HU), compared with 35s (29.42 HU) and 70s (20.3 HU). The ROC curve demonstrated that the largest AUC (0.895) obtained with 25s, with a specificity and sensitivity of 97.87% and 83.64%, respectively. CONCLUSION: The results of our study suggest that early phase CECT with 25 seconds delay may be most helpful for indentifying metastatic lymphadenopathy in PTC patients. The high specificity of CECT can be used in patients with PTC in preoperative nodal staging along with US examinations. Fig.. Comparison of the enhancement value of benign and metastatic lymph nodes in 25s, 35s, and 70s scan delay. A, The time-mean enhancement value curve illustrates that the greatest difference in enhancement value is in the 25s delay. B, CECT with 25s, 35s, and 70s delay in right lateral neck lymph nodes from different patients, note that the metastatic lymph nodes enhance intensely with the 25s delay. Fig. 2. Comparison of AUC in differentiating metastatic from benign cervical lymph nodes in patients with PTC. AUC = area under the curve.

3 SS 02 NR(TH)-03 08:20 Radiofrequency ablation of benign thyroid nodules: prospective multicenter study So Lyung Jung, Jung Hwan Baek 2, Jeong Hyun Lee 2, Jin Yong Sung 3, Kyu Sun Kim 3, Ji-hoon Kim 4, Seon Mi Baek 5, Jung Suk Sim 5, Dong Gyu Na 5 The Catholic University of Korea, Seoul St. Mary s Hospital, 2 Asan Medical Center, 3 Daerim St. Mary s Hospital, 4 Seoul National University Hospital, 5 Human Medical Imaging & Intervention Center, Korea. PURPOSE: To verify the efficacy and safety of RFA for benign thyroid nodules and to verify the factor influencing the volume reduction rate (VRR) in a prospectively performed large population multicenter. MATERIALS AND METHODS: The research committee of Korean Society of Thyroid Radiology (KSThR) organized this study. From May 200 to December 20, 362 nodules of 362 patients (M:F = 45:37; mean age SD, ; range,2 29 years) who met the eligibility criteria and gave written informed consent were enrolled in seven hospitals. Inclusion criteria are as follows: patients with symptomatic problems due to thyroid nodule; patients with cosmetic problems; cytologically confirmed benign thyroid nodule on two separate US-guided fine needle aspiration or core needle biopsy; no malignant US findings, and; serum thyroid hormone and thyrotropin levels within normal range. RF ablation performed using moving shot technique. Patients were followed-up by US and clinical aspects at and 2 months. RESULTS: Finally 29 patients were included with 7 patients follow-up loss. The mean VRR at one, six, and 2 months follow-up were 44.7% 7., 69.2% 6.8 and 80.6% 3.8, respectively. The therapeutic success rate was 97.9% at 2 months follow-up period. The results showed that solidity (p < 0.00) and energy delivered (p = 0.0) were independent factors predicting final volume reduction. The overall complication rate was 4.8%. All of these patients recovered without sequelae, except for one patient with hyperthyroidism. No patient experienced a life-threatening or delayed complication during follow-up. CONCLUSION: Although RFA was effective and safe in previous retrospective studies, this prospective multicenter study verified that the mean VRR and safety were non-inferior to that of existing studies and that solidity and applied energy were independent factors predicting final volume reduction. RFA may be the first-line treatment modality for solid thyroid. Neuroradiology(TH) 35 SS 02 NR(TH)-04 08:30 Core needle biopsy of thyroid nodules: prospective study in consecutive 58 patients Jooae Choe, Jung Hwan Baek, Young Jun Choi, Jeong Hyun Lee Asan Medical Center, Korea. PURPOSE: To prospectively and consecutively assess the diagnostic performance and the potential of core-needle biopsy (CNB) of thyroid nodules. MATERIALS AND METHODS: This prospective study was approved by the Institutional Review Board and informed consent was obtained from all patients. From January 202 to December 202, we evaluated 538 consecutive thyroid nodules from 58 consecutive patients who underwent CNB by one expert radiologist. The reasons for CNB were Bethesda classifications of or 3 in the previous fine needle aspiration result, discordant ultrasonography-pathologic findings, degenerative nodules or others. CNB readings were categorized into the same six categories of the Bethesda System. Final malignant results were diagnosed by histologic results after surgery or CNB. Final benign results were diagnosed by surgery, twice of benign biopsy results, or benign cytology with a stable size at one year follow-up. The incidences of nondiagnostic, inconclusive results, diagnostic performance, unnecessary surgery, and complications were evaluated. Subgroup analysis according to nodule size was performed. RESULTS: CNB was failed in 3 patients because of severe calcifications. CNB achieved.3% of non-diagnostic and 7.8% of inconclusive results. The diagnostic accuracy, sensitivity, specificity, positive predictive value and negative predictive value for diagnosis of malignancy were 9.4%, 84.8%, 00%, 00% and 84.5%, respectively. The unnecessary surgery was 0.6% and complication rate was 0.2%. Subgroup analysis showed that conclusive result rate and sensitivity of nodule size < cm were both significantly higher than nodule size cm. CONCLUSION: This prospective study in consecutive 58 patients demonstrated that CNB achieved low technical failure, non-diagnostic, inconclusive results and high diagnostic accuracy demonstrated with low complication rate. Therefore, CNB seems to be a promising diagnostic tool for thyroid nodules. SS 02 NR(TH)-05 08:40 The role of core-needle biopsy as a first-line diagnostic tool for initially detected thyroid nodules Chong Hyun Suh, Jung Hwan Baek 2, Jeong Hyun Lee 2, Young Jun Choi 2, Jae Kyun Kim 3, Tae Yon Sung 2, Jong Ho Yoon 2, Young Kee Shong 2 Namwon Medical Center, 2 Asan Medical Center, 3 Chung-Ang University Hospital, Korea. PURPOSE: To evaluate the role of core-needle biopsy (CNB) as a first-line diagnostic tool for initially detected thyroid nodules. MATERIALS AND METHODS: This observational study evaluated 632 initially detected thyroid nodules in 632 Neuroradiology(TH) Sep 0, Thu

4 Neuroradiology(TH) Sep 0, Thu 352 KCR 205 consecutive patients who underwent CNB between October 2008 and December 20. CNB results were categorized into the six categories of the Bethesda System. The rates of non-diagnostic and inconclusive results, diagnostic performance, unnecessary surgery, and complications were evaluated. Subgroup analysis based on nodule size was performed. Risk factors for inconclusive results were evaluated by multivariate logistic regression analysis. RESULTS: The rates of non-diagnostic and inconclusive results by CNB were.3% and 5.9%, respectively. The diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value for diagnosis of malignancy were 97.6%, 90.0%, 00%, 00%, and 92.3%, respectively. The rate of unnecessary surgery was 0.6%, and the complication rate was 0.2%. Subgroup analysis showed diagnostic performance was not significantly associated with nodule size. There were no independent risk factors associated with inconclusive results. CONCLUSION: CNB showed low rates of non-diagnostic and inconclusive results and high diagnostic accuracy. CNB also minimized unnecessary surgery. CNB seems to be a promising diagnostic tool for patients with initially detected thyroid nodules. SS 02 NR(TH)-06 08:50 The role of core-needle biopsy for the thyroid nodules with initially non-diagnostic, fine-needle aspiration results: a systematic review and meta-analysis Chong Hyun Suh, Jung Hwan Baek 2, Kyung Won Kim 2, Tae Yon Sung 2, Tae Yong Kim 2, Dong Eun Song 2, Young Jun Choi 2, Jeong Hyun Lee 2 Namwon Medical Center, 2 Asan Medical Center, Korea. PURPOSE: We performed this systematic review and meta-analysis to evaluate the incidence of non-diagnostic result, diagnostic performance, and complications of coreneedle biopsy (CNB) comparing with repeated fine-needle biopsy (FNA), for thyroid nodules with previously nondiagnostic FNA result. MATERIALS AND METHODS: A thorough literature search was conducted in Ovid-MEDLINE and EMBASE databases to identify studies evaluating CNB or repeated FNA for the thyroid nodules with initially non-diagnostic, FNA results. To evaluate the incidence of non-diagnostic results of CNB and repeated FNA, pooled proportions of non-diagnostic results were calculated. Meta-analysis was performed to evaluate the diagnostic accuracy of CNB and repeated FNA for a diagnosis of malignancy. A diagnostic criterion for malignancy was defined as Bethesda category 5 (suspicious for malignancy) and 6 (malignancy). The incidences of complications were also evaluated. RESULTS: A review of 52 articles identified four eligible articles with 028 patients with 028 thyroid nodules for meta-analysis. CNB demonstrated lower non-diagnostic results (6.4%; recalculated,.4%) than repeated FNA (36.5%; recalculated 34.2%). In the three studies that analyzed the diagnostic accuracy of CNB for a diagnosis of malignancy, CNB was highly accurate with a summary sensitivity of 93% (95% CI, 84 98%), a specificity of 00% (95% CI, 89 00%), and partial AUC of Repeated FNA showed a summary sensitivity of 6% (95% CI, 49 73%), a specificity of 00% (95% CI, 98 00%), and partial AUC of In all included studies, there were no major complications in either CNB or repeated FNA. CONCLUSION: Although our meta-analysis demonstrated that both CNB and repeated FNA is acceptable diagnostic tool for thyroid nodules with previously non-diagnostic FNA results, the current evidence in the literature consistently shows CNB demonstrate low non-diagnostic results and high diagnostic accuracy than repeated FNA. Therefore, CNB rather than repeated FNA can be utilized as a subsequent diagnostic approach for thyroid nodules with previous non-diagnostic FNA result. SS 02 NR(TH)-07 09:00 Clinical features of elderly patients aged 65 or older with thyroid cancer: 0-year experience at a single institution Eun Sil Kim, Younghen Lee, Hyungsuk Seo, Nan Hee Kim, Soon Young Kwon, Gil Soo Son Korea University Ansan Hospital, Korea. younghen.lee@gmail.com PURPOSE: According to the 205 estimated cancer incidence in Korea, thyroid cancer was the 4th common cancer, followed by colon, stomach and lung cancers, in women aged 65 years older. Age at diagnosis is important prognostic factors in thyroid cancer, and old age is generally related to poor outcome. However, few reports regarding to characteristics in elderly patients with thyroid cancer. We sought to evaluate the clinical features of thyroid cancers which were diagnosed in the patients aged 65 and older. MATERIALS AND METHODS: Among the 494 patients (M:F = 200:294; mean age, years) who underwent surgery for differentiated thyroid cancer in our institution during recent 0 years, we retrospectively selected the patients aged 65 years and older. Their clinical features including size, number, pathologic type, extrathyroidal extension, symptom of primary tumor, lymph node metastasis (LNM), and results of postoperative surveillances were reviewed. RESULTS: Finally, a total of 26 (M:F = 24:02; mean age, years) patients were enrolled. The mean size and numbers of thyroid cancers were cm,.2.2, respectively. Of 9 papillary thyroid carcinomas, 7 were microcarcinoma. 32 patients with thyroid cancer (mean size, cm) complained of vocal cord palsy or palpable neck mass, while the asymptomatic thyroid cancers of other 94 patients were incidentally detected by US or other imaging modalities (CT or PET). Extrathyroidal extension and LNM were found in 28, and 5 (central:lateral compartment = 4:0) patients, respectively. From 93 patients who were periodically examined by neck US or chest CT examination (mean interval, 39.2 month) following the surgery, 8 patients (8.6%) showed recurrent disease in neck (n = 6), mediastinum (n = ) and lung (n = ).

5 CONCLUSION: Even though the symptomatic thyroid cancer might be relatively prevalent, unfavorable outcome would not be associated with the elderly patients. SS 02 NR(TH)-08 09:0 Large ( 3 cm) thyroid nodule with benign cytology: can thyroid imaging reporting and data system be helpful in predicting false negative cytology? Se Jin Nam, Jin Young Kwak 2, Hee Jung Moon 2, Jung Hyun Yoon 2, Eun-Kyung Kim 2 Inha University Hospital, 2 Severance Hospital, Korea. ekkim@yuhs.ac PURPOSE: To evaluate the false negative rate of fine needle aspiration (FNA) of large thyroid nodule and validate the usefulness of Thyroid Imaging Reporting and Data System (TIRADS) in predicting[i] false negative cytology for large thyroid nodule with benign cytology. MATERIALS AND METHODS: From January 200 to August 204, 632 thyroid nodules with more than 3 cm size (mean size, mm; range, mm) and subsequent benign cytology on US-FNA were included. Reviewing clinical features, false negative rate of cytology was evaluated. US features of internal composition, echogenicity, margin, calcifications, shape were evaluated, and thyroid nodules were classified according to TIRADS. TIRADS category 3 included nodules without any suspicious features of solidity, hypoechogenicity or marked hypoechogenicity, microlobulated or irregular margins, microcalcifications, and taller-than-wide shape. Category 4a, 4b, 4c, and 5 included nodules with one, two, three or four, or five suspicious US features. The malignancy risk was calculated. US feature associated with malignancy for these lesions were analyzed. RESULTS: Of the 632 lesions, 26 lesions (4.%) were malignancy and 606 (95.9%) were benign, suggesting 4.% of false negative rate of FNA cytology. Of the 26 malignant lesions, the final pathology consisted mainly of follicular carcinoma minimally invasive (5 of 26) and follicular variant of papillary carcinoma (9 of 26). One case was a conventional papillary carcinoma and another one case was a malignant lymphoma. The malignancy risks of categories 3, 4a, 4b, and 4c nodules were.3%, 5.%,.2%, and.8%, respectively. In the 64 nodules with surgery, the malignancy risks of category 3, 4a, 4b, and 4c nodules were 5.%, 20.8%, 29.0%, and 50.0%. CONCLUSION: Large thyroid nodule with benign cytology results had relatively high false negative risk of 4.% and TIRADS was helpful in predicting false negative cytology for these lesions. If the large thyroid nodule with benign cytology has any suspicious US feature, it should be considered as image-cytology discordance and additional work up such as core biopsy or surgery should be recommended. Neuroradiology(TH) 353 SS 02 NR(TH)-09 09:20 Huge thyroid mass over 4 cm: in which occasion do you recommend surgery? So Jung Kim, Hye Mi Gweon, Jeong-Ah Kim, Ji Hyun Youk, Eun Ju Son Gangnam Severance Hospital, Korea. ejsonrd@yuhs.ac PURPOSE: To assess the diagnostic performance of fine needle aspiration (FNA) and to determine the prognostic ultrasonographic (US) feature for malignancy in thyroid mass over 4 cm. MATERIALS AND METHODS: We retrospectively reviewed the pathologic results, clinical records and US features of 242 thyroid nodules over 4 cm in diameter (mean size, 4.7 cm; range, 4 9 cm) which were performed FNA between January 200 and December 204 at our institution. Histopathologic results from surgery or imaging follow-up of at least -year were used as the reference standard. Malignancy rate was calculated according to Bethesda category from FNA results. Clinicopathologic characteristics and US features were compared between benign and malignant masses. Multiple logistic regression was used to determine variables that contributed to diagnosis of malignancy. RESULTS: Of a total 242 thyroid nodules in 242 patients, 66 (68.6%) were benign and 76 (3.4%) were malignant. The malignancy rate was 0% (0 of 23) in Bethesda category, 8.% ( of 35) in category 2, 67.4% (29 of 48) in category 3,00% (5 of 5) in category 4, 00% (7 of 7) in category 5 and 00% (4 of 4) in category 6. Of eleven nodules with false negative results (Bethesda category 2) in FNAB, 6 were follicular variant of papillary thyroid carcinoma and 5 were follicular carcinoma. On multivariate analysis, microlobulated or irregular margin, presence of calcification and hypoechogenicity in US features were associated with malignancy. CONCLUSION: In huge thyroid nodules over 4 cm in size, malignancy rate (3.4%) was relatively high with false negative rates of about 8%. The surgery was recommended for higher than Bethesda category 3 in FNA results and repeat FNA was recommended for Bethesda category 2 in thyroid masses over 4 cm. US features can help predict the malignancy of thyroid masses over 4 cm. Neuroradiology(TH) Sep 0, Thu

6 Neuroradiology(TH) Sep 0, Thu 354 KCR 205 Neuroradiology(TH) 09:40-:0 Grand Ballroom 04 Thyroid imaging and intervention 2 Chairperson(s) Jin Yong Sung Daerim St. Mary's Hospital, Korea Jin Young Kwak Yonsei University School of Medicine, Severance Hospital, Korea SS 07 NR(TH)-0 09:40 Evaluation of shear wave elastography (SWE) with transverse and longitudinal scans: differentiation of benign and malignant thyroid nodules Inyoung Youn, Yoon Jung Choi, Seon Hyeong Choi, Shin Ho Kook Kangbuk Samsung Hospital, Korea. yoonjung99.choi@samsung.com PURPOSE: To compare diagnostic performance of transverse and longitudinal planes of shear wave elastography (SWE) for differentiating benign and malignant thyroid nodules. MATERIALS AND METHODS: Between January through July 20, 40 solid thyroid nodules with final pathology of 40 patients (mean age, years) who underwent US-guided FNA and SWE were included in this study. The size and presence of US findings were reviewed on US. We evaluated the correlation between suspicious finding on US and malignancy on final pathology. We calculated mean E max and E mean values in each transverse and longitudinal SWE. ROC analysis was also performed to predict malignancy using the AUC, sensitivity, and specificity, with their 95% CIs in mean E max and E mean value of transverse and longitudinal SWE. RESULTS: There were 6 malignant and 34 benign nodules. The mean size was mm and mm in malignant and benign thyroid nodules without statistical difference (p = 0.425). A comparison of US finding versus final pathology showed statistical difference (p < 0.00). Of malignancy, mean E mean and E max were kpa, kpa on transverse scan, whereas kpa, kpa on longitudinal SWE. The cut-off value of E mean and E max were 44.7 kpa and kpa on transverse scan, whereas kpa and 67.0 kpa on longitudinal scan. E max with kpa on transverse scan showed strongly indicative for malignancy (AUC, 82.4; 95% confidence interval, ), and the sensitivity, specificity, PPV and NPV was 83.3%, 88.2%, 55.6% and 96.8%. CONCLUSION: On transverse SWE with E max was strongly indicative of malignancy, with cut-off value of kpa. Quantified SWE can aid in diagnosing thyroid nodules and can be employed in selecting thyroid nodules for FNA. SS 07 NR(TH)-02 09:50 US elastography for thyroid indeterminate nodules at US Minjung Seong, Jung Hee Shin, Soo Yeon Hahn Samsung Medical Center, Korea. helena35.shin@samsung.com PURPOSE: Although ultrasonography (US) elastography is a promising tool for identifying malignant thyroid nodules, it may be not useful for some selected nodules. The aim of the study was to evaluate the diagnostic performance of US elastography for indeterminate nodules lack of malignant features seen on US. MATERIALS AND METHODS: This retrospective study included 97 thyroid nodules with 96 patients who underwent US elastography with color mapping and strain ratio from October 200 and February 204 at our institution. All of the nodules were followed-up after aspiration or confirmed by histology. Indeterminate nodules at US showed well-defined solid nodules without malignant features. Malignancy was considered when it was more than 50% blue for color mapping and it was.2 or greater for strain ratio. The findings of US elastography were compared with cytopathological results. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of US elastography were evaluated. RESULTS: Of the 97 nodules, 73 (87.8%) were benign and 24 (2.2%) were malignant. There were no significant differences in color mapping and strain ratio between benign and malignant nodules (p = and p = 0.979, respectively). Sensitivity, specificity, PPV, NPV and accuracy were 29%, 77%, 5%, 89%, and 72% for color mapping and 56%, 57%, 4%, 89%, and 56% for strain ratio. Malignancies revealed follicular thyroid carcinoma in 7, follicular variant of papillary thyroid carcinoma (PTC) in 0, classic PTC in 5, metastasis in one and medullary thyroid carcinoma in one. CONCLUSION: US elastography with color mapping and strain ratio has a limitation in differentiating benign and malignant nodules for thyroid nodules categorized as indeterminate on B-mode US. SS 07 NR(TH)-03 0:00 Malignancy risk stratification of thyroid nodules: comparison between the thyroid imaging reporting and data system (TIRADS) and the 204 American Thyroid Association management guidelines in thyroid nodules Jung Hyun Yoon, Eun-Kyung Kim, Hee Jung Moon, Jin Young Kwak Severance Hospital, Korea. docjin@yuhs.ac PURPOSE: To compare the 204 American Thyroid Association (ATA) guideline to Thyroid Imaging Reporting and Data System (TIRADS) in malignancy risk stratification of thyroid nodules. MATERIALS AND METHODS: This retrospective study has been approved by our Institutional Review Board (IRB) with wavier of informed consent. From November 203 to July 204, 293 thyroid nodules in 24 patients (mean age, years) measuring more than 0

7 mm were included in this study. For US features, solidity, hypo- or marked hypoechogenicity, microlobulated to irregular margin, micro- or mixed calcifications, and nonparallel shape were considered as suspicious. A TIRADS category and a 204 ATA guideline pattern was assigned to each nodule. Correlation between TIRADS and the 204 ATA categories to malignancy rate was evaluated using Spearman s rank test. RESULTS: Of the 293 thyroid nodules, 059 (8.9%) were benign and 234 (8.%) were malignant. Forty-four (3.4%) nodules consisted of patterns not specified according to the 204 ATA guideline. Malignancy rate of TIRADS category 3, 4a, 4b, 4c, and 5 was.9% (6/36), 4.2% (7/408), 2.9% (33/256), 49.8% (30/26), and 92.3% (48/52), with significant differences between categories (p < 0.00). Malignancy rate of the very low, low, intermediate, high suspicion for malignancy, and not specified patterns in the 204 ATA guideline was 2.7% (/407), 3.% (0/323), 6.7% (39/233), 58.0% (66/286), and 8.2% (8/44), with significant differences between categories (p < 0.00). High correlation was seen between category/patterns and malignancy rates in TIRADS (r =.000, p < 0.00) and the 204 ATA guidelines (r = 0.900, p = 0.037), without statistically significant differences (Wolfe s test, p = 0.873). CONCLUSION: Both TIRADS and the 204 ATA guideline provides effective malignancy risk stratification for thyroid nodules. Nodules that are not classified into a specific pattern exist according to the 204 ATA guideline, in which reinforcement is needed for more comprehensive diagnostic approach. SS 07 NR(TH)-04 0:0 Comparison of clinical and US characteristics for distinguishing follicular adenoma and carcinoma and the predictive factors of malignancy in thyroid follicular neoplasm Sung Hee Park, Mirinae Seo, Hye-Shin Ahn, Jiin Choi, Hyung Sik Kim 2 Chung-Ang University Hospital, 2 Gachon University Gil Medical Center, Korea. pshee@naver.com Neuroradiology(TH) 355 PURPOSE: To identify the clinical and ultrasonographic (US) features of follicular adenomas and carcinomas to improve the diagnostic accuracy and prediction of malignancy in patients with follicular neoplasm. MATERIALS AND METHODS: This retrospective study included 29 pathologically proven follicular carcinomas and 70 follicular adenomas in 99 patients who underwent thyroid surgery. We analyzed the clinical and US features associated with each tumor, including the patient s age and sex, maximum tumor diameter, internal composition, echogenicity, echotexture, shape, margin, calcification, final assessment, cystic changes, and peripheral halo. The significance of clinical and US variables was determined in a univariate analysis and backward elimination logistic regression analysis. The odds ratios for malignancy were also determined in an area under the receiver operating characteristics curve analysis. RESULTS: In the univariate analysis, a nodule size > 4 cm was more frequent in the follicular adenomas (p = 0.03). Five of 8 examined US features differed significantly between the follicular adenomas and carcinomas. Isoechogenicity and hypoechogenicity, heterogeneous echotexture, an ill-defined margin, microcalcification or rim calcification, and incomplete halo were significantly more frequent in the follicular carcinomas than in the follicular adenomas (p < 0.05). Among the follicular carcinomas, cystic change was more frequent in the widely invasive than in the minimally invasive carcinomas (p = 0.03). In addition, 2 variables, an ill-defined margin and incomplete halo, remained in the final model after performing a multivariate logistic regression analysis. An ill-defined margin was the strongest independent predictive factor, with an odds ratio for malignancy > 307. Incomplete halo was another predictive factor for malignancy with an odds ratio > 34. CONCLUSION: A larger tumor size, heterogeneity, isoechogenicity and hypoechogenicity, microcalcification or rim calcification, an ill-defined margin, and incomplete peripheral halo were more frequently observed in the follicular carcinomas. An ill-defined margin and incomplete halo might be independent predictors of follicular carcinoma when distinguishing follicular adenomas and carcinomas. SS 07 NR(TH)-05 0:20 Can nodular hyperplasia of the thyroid gland be differentiated from follicular adenoma and follicular carcinoma by US? Sun Hye Jeong, Hyun Sook Hong, Eun Hye Lee Soonchunhyang University Bucheon Hospital, Korea. hshong@schmc.ac.kr PURPOSE: To evaluate the ultrasonographic (US) features for differentiation of follicular thyroid lesions. MATERIALS AND METHODS: US features of 56 follicular adenoma (FA) and 36 follicular carcinoma (FC) and 00 nodular hyperplasia (NH) that surgically confirmed were evaluated using univariable and multivariable multinomial logistic regression analyses, receiver operating characteristics analyses and the areas under the curve (AUC). RESULTS: Tumor diameter, margin, echotexture, cystic changes, calcification, hypoechoic rim, and vascularity were significant on univariable analysis. On multivariable logistic regression analyses, tumor diameter (FA: p = 0.002, odds ratio (OR) =.75; FC: p = 0.00, OR = 2.02), absence of cystic changes (FA: p = 0.27, OR = 2.2; FC: p 0.00, OR = 7.74), absence of spongiform appearance (FA: p = 0.234, OR = 0.3; FC: p < 0.00, OR = ), and peripheral vascularity (FA: p = 0.004, OR = 26.64; FC: p < 0.00, OR = ) differed significantly among the three follicular lesions, with NH as a reference. The AUCs for NH, FA, and FC were 0.844, 0.858, and and diagnostic accuracy was 72.6%. CONCLUSION: Tumor diameter, cystic changes, spongiform appearance, and peripheral vascularity differed significantly among follicular lesions. The diagnostic capability was moderate. Neuroradiology(TH) Sep 0, Thu

8 Neuroradiology(TH) Sep 0, Thu 356 KCR 205 SS 07 NR(TH)-06 0:30 Initial clinical experience with BRAF V600E mutation analysis of core-needle biopsy from thyroid nodules Sang Hyun Choi, Jung Hwan Baek, Jeong Hyun Lee, Young Jun Choi, Eun Ju Ha 2 Asan Medical Center, 2 Ajou University Hospital, Korea. PURPOSE: The accurate diagnosis of thyroid nodules is important for making management decisions. The purpose of this study is to evaluate the feasibility of core-needle biopsy with BRAF V600E mutation analysis (CNB+ BRAF V600E ) and to compare the clinical usefulness of CNB+BRAF V600E and fine-needle aspiration with BRAF V600E mutation analysis (FNA+BRAF V600E ) in the diagnosis of thyroid malignancy. MATERIALS AND METHODS: The results of BRAF V600E mutation analyses of 820 nodules from 820 patients (M:F = 53:667; mean age, 5. years), who underwent CNB+BRAF V600E (n = 256) or FNA+BRAF V600E (n = 564) between January 20 and March 202 were retrospectively evaluated. The feasibility of CNB+BRAF V600E was assessed by comparing its rate of detection of BRAF V600E mutations and positive predictive value with those of FNA+BRAF V600E. The clinical usefulness of CNB+ BRAF V600E was determined by comparing rates of inconclusive results, the additional value of BRAF V600E mutation analysis, diagnostic surgery, and diagnostic performance with those of FNA+BRAF V600E. RESULTS: CNB+BRAFV600E and FNA+BRAF V600E had similar rates of BRAF V600E mutation detection (66.3% vs. 64.4%, p = 0.883) and positive predictive value (00.0% vs. 96.6%, p = 0.35). CNB+BRAF V600E had a significantly higher diagnostic accuracy rate (95.7% vs. 85.9%, p < 0.00), and significantly lower rates of inconclusive results (8.2% vs. 5.8%, p < 0.00), and diagnostic surgery (8.9% vs. 22.3%, p = 0.006), than FNA+ BRAF V600E. CONCLUSION: The greater diagnostic performance of CNB+BRAF V600E and its lower rate of inconclusive results than FNA+BRAF V600E suggest that CNB+BRAF V600E can reduce rates of preventable diagnostic surgery. MATERIALS AND METHODS: A consecutive 06 thyroid nodules (mean size, ) were included among 20 nodules in which core needle biopsy was performed during a year period. The 95 nodules were excluded by exclusion criteria (postoperative recurrence 2, previous ablation therapy, predominantly cystic nodules, nodules with mixed echogenicity 63, rim or severe calcification 6, inadequate specimen, and unavailable pathology slide ). The nodule echogenicity was categorized by an experience thyroid radiologist as 3 grades (marked hypoechogenicity, mild hypoechogenicity, and isoechogenicity). The histopathology of biopsy specimen was evaluated by an experienced pathologist regarding the histology components (fibrosis, follicular lesion, lymphoid infiltration), architecture of follicular lesion (microfollicular formation and uniformity of follicles), and overall cellularity. We analyzed the relationship between nodule echogenicity and histopathologic features. RESULTS: The echogenicity of nodules were isohyperechoic 35 (33%), mildly hypoechoic 37 (34.9%), and markedly hypoechoic 34 (32.%). The nodule hypoechogenicity (marked or mild degree) was significantly associated with histopathologic features of extensive fibrosis (> 60%) (p = 0.002), severe microfollicle formations (> 90%) (p = 0.008), uniform follicular pattern (p = 0.04), and markedly high cellularity by univariate analysis (p = 0.026), and extensive fibrosis was independently associated with hypoechogenicity (p = 0.04). In 73 nodules with predominant follicular lesions (> 60%) of biopsy specimen, severe microfollicle formations, follicular uniformity, and markedly high cellularity were significantly associated with hypoechogenicity (p 0.026). There was a significant correlation between the nodule echogenicity and histopathology features of fibrosis and follicular uniformity (r = 0.520, p < 0.00 and r = 0.240, p = 0.04, respectively). CONCLUSION: The hypoechogenicity of thyroid nodules is associated with histopathologic features of extensive fibrosis, extensive microfollicle formation, uniform follicular pattern, and markedly high cellularity, and the nodule echogenicity correlates with the degree of fibrosis and follicular uniformity. SS 07 NR(TH)-07 0:40 The relationship of US echogenicity and histopathologic features in thyroid nodules: histopathologic correlation by core needle biopsy Dong Gyu Na, Hunkyung Lee 2, Soo Jin Kim 3, Dae Sik Kim 4 Human Medical Imaging & Intervention Center, 2 Ewha Clinical Laboratory, 3 New Korea Hospital, Human Medical Imaging & Intervention Center, 4 Incheon Medical Center, Human Medical Imaging & Intervention Center, Korea. nndgna@gmail.com PURPOSE: The relationship between nodule echogenicity and histopthologic features has not been established. The purpose of this study was to determine the histopathologic features associated with echogenicity of thyroid nodules.

9 SS 07 NR(TH)-08 0:50 Preoperative US of papillary thyroid carcinoma (PTC): evaluation of utility and accuracy of predictive factors for extrathyroidal extension Hye Shin Ahn, Sung Hee Park, Soo Jin Kim, Mirinae Seo Chung-Ang University Hospital, Korea. PURPOSE: To evaluate predictive factors of the extrathyroidal extension of papillary thyroid carcinoma (PTC) on preoperative ultrasound (US) and compare utility and accuracy of factors for diagnostic performance. MATERIALS AND METHODS: This study included preoperative US of 39 PTC which confirmed by surgery between November 20 and March 202. We retrospectively reviewed variable US findings of nodules including several measuring methods for contact the thyroid capsule of the nodule (degree of perimeter ratio (%), abutting length to the capsule (mm), presence of protrusion (yes/no). US findings were compared with pathologic results after surgery and diagnostic accuracy of each US finding was calculated. RESULTS: Of the 39 PTC, extrathyroidal extension was present in 50 (36%) based on pathologic results (84% sensitivity, 59.6% specificity, 53.8% positive predictive value, and 86.9% negative predictive value). Mean size of the nodule was significantly different between PTC with and without extrathyroidal extension (p = 0.000). US T- stage was predicted extrathyroidal extension (p = 0.000). All of measuring methods for contact thyroid capsule of the nodule were statistically correlated with extrathyroidal extension in univariate analysis (p < 0.05). In multivariate analysis, More than 25% of perimeter ratio of nodule showed highest odds ratio (OR, 8.429; 95% CL, ). CONCLUSION: Preoperative US is a helpful to predict extrathyroidal extension of papillary thyroid cancer. Lesion size and T-stage on US were useful predictive factors for extrathyroidal extension. Among US finding of contact thyroid capsule, more than 25% of perimeter ratio showed highest odds ratio. Neuroradiology(TH) 357 SS 07 NR(TH)-09 :00 Diagnosis of metastasis to the thyroid gland: comparison of core-needle biopsy and fineneedle aspiration Sang Hyun Choi, Jung Hwan Baek, Jeong Hyun Lee, Young Jun Choi, Eun Ju Ha 2 Asan Medical Center, 2 Ajou University Hospital, Korea. PURPOSE: Early detection and diagnosis of metastasis to the thyroid gland is important. The purpose of this study is to evaluate the clinical value of core-needle biopsy (CNB) by comparing the results of CNB and fine-needle aspiration (FNA) in patients with clinically suspected metastasis to the thyroid gland. MATERIALS AND METHODS: From January 200 to December 203, 52 thyroid nodules from 52 patients with clinically suspected metastasis to the thyroid gland (M:F = 26:26; mean age, 62.8 years) were retrospectively analyzed. Of these 52 patients, FNA was initially used in 4 patients. CNB was used in 20 patients, i.e. in patients as the initial approach and in nine patients after inconclusive FNA results. Ultrasound features of metastasis to the thyroid gland were evaluated. The diagnostic performance, repeated diagnostic examination rate, and diagnostic surgery rate were also evaluated for FNA and CNB. RESULTS: Among these 52 patients, 46 were diagnosed as having thyroid metastases and six were diagnosed as having primary thyroid cancer. Common ultrasound features were an ovoid to round shape (58.7%); ill-defined margin (56.5%); hypoechogenicity (65.2%); and no calcifications (87.0%). CNB achieved a significantly higher sensitivity than FNA (00.0% vs. 58.6%, p = 0.008) without any false negative results. Both the repeated diagnostic examination rate and the diagnostic surgery rate were significantly lower in CNB than in FNA (5.0% vs. 46.3%, p = 0.00; 5.0% vs. 34.%, p = 0.03). CONCLUSION: CNB is more useful than FNA in patients with clinically suspected metastasis to the thyroid gland. Neuroradiology(TH) Sep 0, Thu