Radiofrequency ablation (RFA) is a minimally invasive treatment modality used as an alternative to surgery in patients with benign thyroid nodules, recurrent thyroid cancers (RTCs), and primary thyroid microcarcinomas. The Korean Society of Thyroid Radiology (KSThR) initially developed recommendations for the optimal use of RFA for thyroid tumors in 2009 and revised them in 2012 and 2017. As new meaningful evidence has accumulated since 2017 and in response to a growing global interest in the use of RFA for treating malignant thyroid lesions, the task force committee members of the KSThR decided to update the guidelines on the use of RFA for the management of RTCs based on a comprehensive analysis of current literature and expert consensus.

Objective: To compare the quality of deep learning-reconstructed turbo spin-echo (DL-TSE) and conventionally interpolated turbo spin-echo (Conv-TSE) techniques in contrast-enhanced MRI of the neck. Materials and Methods: Contrast-enhanced T1-weighted DL-TSE and Conv-TSE images were acquired using 3T scanners from 106 patients. DL-TSE employed a closed-source, ‘work-in-progress’ (WIP No. 1062, iTSE, version 10; Siemens Healthineers) algorithm for interpolation and denoising to achieve the same in-plane resolution (axial: 0.26 x 0.26 mm 2 ; coronal: 0.29 x 0.29 mm 2 ) while reducing scan times by 15.9% and 52.6% for axial and coronal scans, respectively. The full width at half maximum (FWHM) and percent signal ghosting were measured using stationary and flow phantom scans, respectively. In patient images, non-uniformity (NU), contrast-to-noise ratio (CNR), and regional mucosal FWHM were evaluated. Two neuroradiologists visually rated the patient images for overall quality, sharpness, regional mucosal conspicuity, artifacts, and lesions using a 5-point Likert scale. Results: FWHM in the stationary phantom scan was consistently sharper in DL-TSE. The percent signal ghosting outside the flow phantom was lower in DL-TSE (0.06% vs. 0.14%) but higher within the phantom (8.92% vs. 1.75%) compared to ConvTSE. In patient scans, DL-TSE showed non-inferior NU and higher CNR. Regional mucosal FWHM was significantly better in DL-TSE, particularly in the oropharynx (coronal: 1.08 ± 0.31 vs. 1.52 ± 0.46 mm) and hypopharynx (coronal: 1.26 ± 0.35 vs. 1.91 ± 0.56 mm) (both P < 0.001). DL-TSE demonstrated higher overall image quality (axial: 4.61 ± 0.49 vs. 3.32 ± 0.54) and sharpness (axial: 4.40 ± 0.56 vs. 3.11 ± 0.53) (both P < 0.001). In addition, mucosal conspicuity was improved, especially in the oropharynx (axial: 4.41 ± 0.67 vs. 3.40 ± 0.69) and hypopharynx (axial: 4.45 ± 0.58 vs. 3.58 ± 0.63) (both P < 0.001).Extracorporeal ghost artifacts were reduced in DL-TSE (axial: 4.32 ± 0.60 vs. 3.90 ± 0.71, P < 0.001) but artifacts overlapping anatomical structures were slightly more pronounced (axial: 3.78 ± 0.74 vs. 3.95 ± 0.72, P < 0.001). Lesions were detected with higher confidence in DL-TSE. Conclusion DL-based reconstruction applied to accelerated neck MRI improves overall image quality, sharpness, mucosal conspicuity in motion-prone regions, and lesion detection confidence. Despite more pronounced ghost artifacts overlapping anatomical structures, DL-TSE enables substantial scan time reduction while enhancing diagnostic performance.

Radiofrequency ablation (RFA) is a minimally invasive treatment modality used as an alternative to surgery in patients with benign thyroid nodules, recurrent thyroid cancers (RTCs), and primary thyroid microcarcinomas. The Korean Society of Thyroid Radiology (KSThR) initially developed recommendations for the optimal use of RFA for thyroid tumors in 2009 and revised them in 2012 and 2017. As new meaningful evidence has accumulated since 2017 and in response to a growing global interest in the use of RFA for treating malignant thyroid lesions, the task force committee members of the KSThR decided to update the guidelines on the use of RFA for the management of RTCs based on a comprehensive analysis of current literature and expert consensus.

Objective: To compare the quality of deep learning-reconstructed turbo spin-echo (DL-TSE) and conventionally interpolated turbo spin-echo (Conv-TSE) techniques in contrast-enhanced MRI of the neck. Materials and Methods: Contrast-enhanced T1-weighted DL-TSE and Conv-TSE images were acquired using 3T scanners from 106 patients. DL-TSE employed a closed-source, ‘work-in-progress’ (WIP No. 1062, iTSE, version 10; Siemens Healthineers) algorithm for interpolation and denoising to achieve the same in-plane resolution (axial: 0.26 x 0.26 mm 2 ; coronal: 0.29 x 0.29 mm 2 ) while reducing scan times by 15.9% and 52.6% for axial and coronal scans, respectively. The full width at half maximum (FWHM) and percent signal ghosting were measured using stationary and flow phantom scans, respectively. In patient images, non-uniformity (NU), contrast-to-noise ratio (CNR), and regional mucosal FWHM were evaluated. Two neuroradiologists visually rated the patient images for overall quality, sharpness, regional mucosal conspicuity, artifacts, and lesions using a 5-point Likert scale. Results: FWHM in the stationary phantom scan was consistently sharper in DL-TSE. The percent signal ghosting outside the flow phantom was lower in DL-TSE (0.06% vs. 0.14%) but higher within the phantom (8.92% vs. 1.75%) compared to ConvTSE. In patient scans, DL-TSE showed non-inferior NU and higher CNR. Regional mucosal FWHM was significantly better in DL-TSE, particularly in the oropharynx (coronal: 1.08 ± 0.31 vs. 1.52 ± 0.46 mm) and hypopharynx (coronal: 1.26 ± 0.35 vs. 1.91 ± 0.56 mm) (both P < 0.001). DL-TSE demonstrated higher overall image quality (axial: 4.61 ± 0.49 vs. 3.32 ± 0.54) and sharpness (axial: 4.40 ± 0.56 vs. 3.11 ± 0.53) (both P < 0.001). In addition, mucosal conspicuity was improved, especially in the oropharynx (axial: 4.41 ± 0.67 vs. 3.40 ± 0.69) and hypopharynx (axial: 4.45 ± 0.58 vs. 3.58 ± 0.63) (both P < 0.001).Extracorporeal ghost artifacts were reduced in DL-TSE (axial: 4.32 ± 0.60 vs. 3.90 ± 0.71, P < 0.001) but artifacts overlapping anatomical structures were slightly more pronounced (axial: 3.78 ± 0.74 vs. 3.95 ± 0.72, P < 0.001). Lesions were detected with higher confidence in DL-TSE. Conclusion DL-based reconstruction applied to accelerated neck MRI improves overall image quality, sharpness, mucosal conspicuity in motion-prone regions, and lesion detection confidence. Despite more pronounced ghost artifacts overlapping anatomical structures, DL-TSE enables substantial scan time reduction while enhancing diagnostic performance.

Background: The diagnosis of tuberculous pleural effusion (TPE) often relies on pleural fluid adenosine deaminase (ADA) levels. The diagnostic utility of ADA, however, is influenced by the prevalence of tuberculosis (TB) in local populations. Malignant pleural effusion (MPE) cases can exhibit moderately elevated ADA levels comparable to those seen in TPE. As population aging potentially impacts ADA levels, global TB incidence is decreasing whereas the burden of malignancy is on the rise. Consequently, epidemiological shifts and temporal changes in ADA distribution complicate the differential diagnosis between TPE and MPE when ADA levels are within the 40–70 IU/L range. Nonetheless, data specific to this subset are scarce. Methods: This retrospective study included consecutive patients aged > 18 years with confirmed TPE and MPE, spanning from 2012 to 2023. ADA levels in pleural fluid were categorized into three groups: < 40 IU/L, 40–70 IU/L, and > 70 IU/L. The study examined annual trends in the frequency of new cases and ADA level distributions over time and identified discriminating factors between TPE and MPE in cases with ADA levels of 40–70 IU/L. Results: In total, 297 TPE and 369 MPE cases were included in this study. Over the study period, the frequency of TPE progressively declined, while that of MPE increased. In the most recent four-year period, new TPE and MPE cases with ADA levels of 40–70 IU/L occurred at comparable numbers. Multivariable analysis identified pleural fluid carcinoembryonic antigen (CEA) levels and the number of focal pleural nodules as independent predictors for MPE. Specifically, the presence of either CEA levels > 15.7 ng/mL or more than eight pleural nodules yielded the highest diagnostic accuracy with a sensitivity of 88%, specificity of 100%, and an area under the curve of 0.95. Conclusion The differential diagnosis between TPE and MPE with pleural ADA levels of 40–70 IU/L has become increasingly critical due to evolving epidemiological patterns and ADA distribution changes over time. Pleural fluid CEA levels and the characteristics of pleural nodules may offer valuable guidance in distinguishing between TPE and MPE within this diagnostic gray zone.

Background: Group B Streptococcus (GBS) is one of the leading causes of neonatal earlyonset sepsis, resulting in high mortality and significant comorbidity. Intrapartum penicillin prophylaxis is recommended for pregnant women with GBS colonization to prevent vertical transmission. For pregnant women at high risk of anaphylaxis to penicillin, clindamycin is recommended only if the susceptibility of GBS isolates has been identified. We retrospectively examined the GBS detection rate and clindamycin resistance among Korean women of reproductive age over the last 20 years. Methods: Microbiologic studies using vaginal, vaginal–rectal or vaginal–perianal swabs from female patients 15–49 years of age during 2003–2022 were reviewed. Annual GBS detection rates and clindamycin resistance rates were calculated. The study period was divided into two periods (period 1, 2003–2015; period 2, 2016–2022) based on the introduction of universal culture-based GBS screening in our center in 2016. GBS detection rates and clindamycin resistance rates were compared between the periods using χ2 tests. Results: A total of 14,571 women were tested 16,879 times and GBS was isolated in 1,054 tests (6.2%), with 423 clindamycin-resistant isolates (40.1%). The GBS detection rate increased from 3.4% (301/8,869) in period 1 to 9.4% (2,753/8,010) in period 2 (P < 0.001). Even during period 1, the GBS detection rate was higher in 2009–2015 compared to 2003–2008 (P < 0.001). Clindamycin resistance rates have remained at similar levels since 2009, which were 39.5% (199/301) in period 1 and 40.2% (303/753) in period 2 (P = 0.833). Conclusion This study demonstrated that GBS detection rates in Korean women of reproductive age significantly increased almost three times during the twenty years of the study period, with a persistently high clindamycin resistance rate of up to 40%.

Objective: : In degenerative lumbar spondylolisthesis, interbody fusion surgery (IFS) has long been recommended as the gold standard of surgical management. However, IFS is less recommended for high-risk patients such as the elderly because it involves extensive surgery, with a long operation time and high volumes of blood loss, which lead to marked perioperative morbidity. We report an alternative primary and salvage treatment technique for high-risk lumbar spondylolisthesis through posterior lumbar element reinforcement using interspinous fixation and decompression alone without interbody fusion. Methods: : Plain radiographs, computed tomography scans, and magnetic resonance imaging, taken at different intervals, were used to measure local disc height (DH), vertebral body slippage (BS), and segmental motion angle (SMA). A Visual analogue scale and the Oswestry disability index (ODI) were applied pre-operation and at the last follow-up. Results: : The local SMA decreased significantly by 3.46°±3.07°, from 10.61°±3.42° preoperatively to 7.15±3.70 at the last follow-up (p<0.001). The DH decreased from 8.61±2.88 mm preoperatively to 8.41±2.48 mm at the last follow-up (p=0.074). The BS decreased from 3.49±4.29 mm preoperatively to 3.41±4.91 mm at the last follow-up (p=0.092). None of the patients reported worsening pain or an increased ODI after surgery, and there were no surgery-related complications. Conclusion : Posterior lumbar element reinforcement by decompression alone with SPIRE™ fixation is an alternative primary and salvage treatment option for select patients with spondylolisthesis.

Background: The diagnosis of tuberculous pleural effusion (TPE) often relies on pleural fluid adenosine deaminase (ADA) levels. The diagnostic utility of ADA, however, is influenced by the prevalence of tuberculosis (TB) in local populations. Malignant pleural effusion (MPE) cases can exhibit moderately elevated ADA levels comparable to those seen in TPE. As population aging potentially impacts ADA levels, global TB incidence is decreasing whereas the burden of malignancy is on the rise. Consequently, epidemiological shifts and temporal changes in ADA distribution complicate the differential diagnosis between TPE and MPE when ADA levels are within the 40–70 IU/L range. Nonetheless, data specific to this subset are scarce. Methods: This retrospective study included consecutive patients aged > 18 years with confirmed TPE and MPE, spanning from 2012 to 2023. ADA levels in pleural fluid were categorized into three groups: < 40 IU/L, 40–70 IU/L, and > 70 IU/L. The study examined annual trends in the frequency of new cases and ADA level distributions over time and identified discriminating factors between TPE and MPE in cases with ADA levels of 40–70 IU/L. Results: In total, 297 TPE and 369 MPE cases were included in this study. Over the study period, the frequency of TPE progressively declined, while that of MPE increased. In the most recent four-year period, new TPE and MPE cases with ADA levels of 40–70 IU/L occurred at comparable numbers. Multivariable analysis identified pleural fluid carcinoembryonic antigen (CEA) levels and the number of focal pleural nodules as independent predictors for MPE. Specifically, the presence of either CEA levels > 15.7 ng/mL or more than eight pleural nodules yielded the highest diagnostic accuracy with a sensitivity of 88%, specificity of 100%, and an area under the curve of 0.95. Conclusion The differential diagnosis between TPE and MPE with pleural ADA levels of 40–70 IU/L has become increasingly critical due to evolving epidemiological patterns and ADA distribution changes over time. Pleural fluid CEA levels and the characteristics of pleural nodules may offer valuable guidance in distinguishing between TPE and MPE within this diagnostic gray zone.

Background: Group B Streptococcus (GBS) is one of the leading causes of neonatal earlyonset sepsis, resulting in high mortality and significant comorbidity. Intrapartum penicillin prophylaxis is recommended for pregnant women with GBS colonization to prevent vertical transmission. For pregnant women at high risk of anaphylaxis to penicillin, clindamycin is recommended only if the susceptibility of GBS isolates has been identified. We retrospectively examined the GBS detection rate and clindamycin resistance among Korean women of reproductive age over the last 20 years. Methods: Microbiologic studies using vaginal, vaginal–rectal or vaginal–perianal swabs from female patients 15–49 years of age during 2003–2022 were reviewed. Annual GBS detection rates and clindamycin resistance rates were calculated. The study period was divided into two periods (period 1, 2003–2015; period 2, 2016–2022) based on the introduction of universal culture-based GBS screening in our center in 2016. GBS detection rates and clindamycin resistance rates were compared between the periods using χ2 tests. Results: A total of 14,571 women were tested 16,879 times and GBS was isolated in 1,054 tests (6.2%), with 423 clindamycin-resistant isolates (40.1%). The GBS detection rate increased from 3.4% (301/8,869) in period 1 to 9.4% (2,753/8,010) in period 2 (P < 0.001). Even during period 1, the GBS detection rate was higher in 2009–2015 compared to 2003–2008 (P < 0.001). Clindamycin resistance rates have remained at similar levels since 2009, which were 39.5% (199/301) in period 1 and 40.2% (303/753) in period 2 (P = 0.833). Conclusion This study demonstrated that GBS detection rates in Korean women of reproductive age significantly increased almost three times during the twenty years of the study period, with a persistently high clindamycin resistance rate of up to 40%.

Objective: : In degenerative lumbar spondylolisthesis, interbody fusion surgery (IFS) has long been recommended as the gold standard of surgical management. However, IFS is less recommended for high-risk patients such as the elderly because it involves extensive surgery, with a long operation time and high volumes of blood loss, which lead to marked perioperative morbidity. We report an alternative primary and salvage treatment technique for high-risk lumbar spondylolisthesis through posterior lumbar element reinforcement using interspinous fixation and decompression alone without interbody fusion. Methods: : Plain radiographs, computed tomography scans, and magnetic resonance imaging, taken at different intervals, were used to measure local disc height (DH), vertebral body slippage (BS), and segmental motion angle (SMA). A Visual analogue scale and the Oswestry disability index (ODI) were applied pre-operation and at the last follow-up. Results: : The local SMA decreased significantly by 3.46°±3.07°, from 10.61°±3.42° preoperatively to 7.15±3.70 at the last follow-up (p<0.001). The DH decreased from 8.61±2.88 mm preoperatively to 8.41±2.48 mm at the last follow-up (p=0.074). The BS decreased from 3.49±4.29 mm preoperatively to 3.41±4.91 mm at the last follow-up (p=0.092). None of the patients reported worsening pain or an increased ODI after surgery, and there were no surgery-related complications. Conclusion : Posterior lumbar element reinforcement by decompression alone with SPIRE™ fixation is an alternative primary and salvage treatment option for select patients with spondylolisthesis.