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.

This guideline outlines the use of 18F-fluoro-2-deoxyglucose positron emission tomography / computed tomography for the diagnosis and management of infectious and inflammatory diseases. It provides detailed recommendations for healthcare providers on patient preparation, imaging procedures, and the interpretation of results. Adapted from international standards and tailored to local clinical practices, the guideline emphasizes safety, quality control, and effective use of the technology in various conditions, including spinal infections, diabetic foot, osteomyelitis, vasculitis, and cardiac inflammation. The aim is to assist nuclear medicine professionals in delivering accurate diagnoses and improving patient outcomes while allowing flexibility to adapt to individual patient needs, technological advancements, and evolving medical knowledge. This document is a comprehensive resource for enhancing the quality and safety of 18F-fluoro-2-deoxyglucose positron emission tomography / computed tomography for the evaluation of infectious and inflammatory diseases.Preamble The Korean Society of Nuclear Medicine (KSNM) was established in 1961 to promote the clinical and technological advancement of nuclear medicine in South Korea, with members that include nuclear medicine physicians and associated scientists. The KSNM regularly formulates and revises procedural guidelines for nuclear medicine examinations to enhance the field and improve the quality of patient care. These guidelines are designed to support healthcare professionals in providing appropriate medical care to patients. However, they are not immutable rules or mandatory requirements for conducting examinations.Therefore, KSNM states that these guidelines should not be used in legal actions challenging a healthcare professional’s medical decisions. The ultimate judgment regarding specific procedures or appropriate measures should be made by nuclear medicine physicians, considering the unique circumstances of each case. Deviation from these guidelines does not imply substandard medical practice. Rather, reasonable judgments differing from the guidelines can be made based on the patient’s condition, available resources, and advancements in knowledge or technology. Due to the diversity and complexity of patients, it is often challenging to predict the most appropriate diagnostic and accurate therapeutic responses. Thus, adherence to these guidelines does not always guarantee an exact diagnosis or successful outcomes.The purpose of this guideline is to assist healthcare providers in making reasonable decisions and conducting effective and safe examinations based on current medical knowledge, available resources, and patient needs when performing 18F-fluoro-2-deoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) examinations for infectious/ inflammatory diseases.

Background: Infantile hemangioma (IH) is a common benign vascular tumor that occurs during infancy. Oral propranolol is used as a first-line treatment. However, standardized guidelines for evaluating treatment efficacy, particularly the appropriate timing and parameters for Doppler ultrasound (US), have not been established. This study reports on the evaluation of therapeutic efficacy of oral propranolol solution in IH patients using Doppler US, and aims to propose the appropriate timing and parameters for using Doppler US based on this experience. Methods: A retrospective analysis was conducted on 120 patients with IH who were treated with oral propranolol solution and maintained for over 6 months from May 2017 to April 2023. Doppler US evaluation of IH was performed at diagnosis, 1-2 and 6-12 months after treatment initiation, and 6 months post-therapy cessation. A complete response (CR) was identified as a reduction in vascularity along with a decrease in longest diameter (LD) or thickness of 50% or more. Recurrence was evaluated based on increased vascularity or size 6 months after treatment discontinuation. Results: Of 120 patients with IH, 82 females and 38 males were analyzed. IH was first detected at a median age of 12 days (range, 1-240 days), and treatment began at 76 days (range, 27-570 days), continuing for an average of 10.4 months (range, 5-24 months). Initial Doppler US measurements showed an LD of 2.65±1.52 cm and a thickness of 0.79±0.55 cm, with prominent vascularity. After 1-2 months of treatment, LD and thickness decreased by 12.9% and 25.9%, respectively. By 6-12 months, reductions reached 37.2% and 53.6%. CR occurred in 77 patients (64.2%) after 6-12 months of treatment. Eleven patients (9.2%) experienced a recurrence. Conclusion Doppler US is a valuable modality for evaluating the characteristics, treatment response, and recurrence of IH treated with oral propranolol.

Background: The treatment of Kümmell disease (KD) is controversial. Corpectomy and reconstruction or osteotomy with long-level fusion was traditionally performed for the advanced KD. However, these procedures can be disadvantageous for elderly patients.Several alternative surgical procedures including transpedicular intravertebral cage augmentation (TPICA) or vertebroplasty (VP) combined with short-segment fixation (SSF) have been suggested to minimize the surgical burden. This study aimed to compare the outcomes of percutaneous TPICA plus SSF with VP plus SSF for advanced thoracolumbar (T11–L2) KD and to introduce our novel percutaneous TPICA technique using specially designed cannulated cage trials. Methods: We devised specially designed cannulated cage trials to make the TPICA procedure safer and more reproducible, minimizing the risk of the pedicle medial wall violation. All consecutive patients who underwent percutaneous TPICA or VP combined with SSF for advanced thoracolumbar KD, from January 2021 to June 2022, with ≥ 1-year follow-up at a single institution, were included. Perioperative details, clinical outcomes (visual analog scale and Oswestry Disability Index), and radiological outcomes (anterior vertebral body compression percentage and vertebral kyphotic angle [VKA] of the fractured vertebra, and local Cobb angle [LCA]) were collected and compared between the groups. Results: A total of 42 patients were enrolled, with 21 patients in each group. There were no patients with pedicle medial wall fracture in the TPICA group. Both procedures provided significantly favorable radiological outcomes compared to those preoperatively. No significant differences were observed in the changes over time in all radiological parameters between the groups. Loss of correction during the follow-up period was significantly smaller in patients with TPICA than in those with VP in VKA (median [interquartile range], 2.15 [0.30–2.80] vs. 2.90 [0.90–6.53]; p = 0.030) and LCA (2.70 ± 2.90 vs. 5.17 ± 4.40, p = 0.037). Conclusions Both procedures are minimally invasive and useful options for advanced KD, especially for elderly patients with high comorbidity. Our novel percutaneous TPICA technique using cannulated cage trials, being safer and more reproducible, may allow spine surgeons to easily perform TPICA.

Background: In this comprehensive retrospective nationwide cohort study, we examined the relationships between various asthma medications and bone health, utilizing data from the National Health Insurance Service database of South Korea. Methods: From 2015 to 2019, the relevant dataset included 168,611 individuals aged 66 years, among whom 8,747 were diagnosed with asthma. We focused on a subset of 6,173 patients, all 66-year-old women. Participants were categorized into four groups: nonusers of asthma medication (n=2,868), leukotriene antagonist users (n=2,281), inhaled corticosteroid (ICS) users (n=517), and those using a combination of ICS and long-acting beta-agonist (ICS+LABA) medication (n=507). The primary outcomes measured were the incidences of major osteoporotic fractures and hip fractures during the follow-up period. Results: Over 2.7 years of follow-up, 615 cases of major osteoporotic fractures and 96 cases of hip fractures were recorded. ICS users exhibited a heightened risk of both injuries, with hazard ratios of 1.38 (95% confidence interval [CI], 1.18 to 1.63; P<0.001) for major osteoporotic fractures and 1.56 (95% CI, 1.33 to 1.83; P<0.001) for hip fractures. Similarly elevated risks were observed in the ICS+LABA group. Notably, the risk associated with ICS was particularly pronounced among patients with osteopenia for both fracture types. Overall, the use of ICS, alone or in combination with LABA, in patients with asthma is associated with significantly increased risks of osteoporotic fractures, especially among those with osteopenia. Conclusion These findings underscore the importance of considering bone health when managing asthma, especially in older patients and those with existing bone density issues.

Purpose: This study aimed to explore the effects of both the presence and size of posterior subependymal germinal matrix hemorrhage (PS-GMH), considered a mild form of hemorrhage, on the neurodevelopmental outcomes of extremely preterm infants. Methods: A retrospective analysis was conducted on 221 extremely preterm infants, assessing their initial and term-equivalent age (TEA) cranial ultrasound (cUS) examinations from 2016 to 2021. Infants were classified based on the presence and size (small/large) of PS-GMH. Neurodevelopmental outcomes at corrected ages of 18-24 months were analyzed in 135 infants. Results: PS-GMH was identified in 86.9% (192/221) of the infants, with 13.5% (26/192) exhibiting large PS-GMH. Among the 135 infants who were followed up, those with PS-GMH were found to have younger gestational ages (P<0.001) and a higher incidence of maternal chorioamnionitis (P=0.016) than those without PS-GMH. Significant differences were observed in the incidence of grade II intraventricular hemorrhage (IVH) on initial cUS (P=0.003) and ventriculomegaly at TEA cUS (P=0.026) across the groups with no PS-GMH, small PS-GMH, and large PS-GMH. The large PS-GMH group exhibited a higher occurrence of grade II IVH than the small PS-GMH group (P=0.006). However, ventriculomegaly incidence did not significantly vary with PS-GMH status. Neurodevelopmental outcomes were also not significantly different across PS-GMH statuses. The adjusted odds ratios for any neurodevelopmental impairment, compared to the no PS-GMH group, were 1.70 (95% confidence interval [CI], 0.40 to 7.26; P=0.471) for all PS-GMH, 1.61 (95% CI, 0.37 to 6.93; P=0.526) for small PS-GMH, and 3.84 (95% CI, 0.62 to 24.00; P=0.150) for large PS-GMH. Conclusion PS-GMH was frequently observed in extremely preterm infants; however, it did not independently predict adverse neurodevelopmental outcomes.

Purpose: This study assessed the impact of hepatic fibrosis on the diagnostic performance of the controlled attenuation parameter (CAP) in quantifying hepatic steatosis in patients with chronic hepatitis B (CHB). Methods: CHB patients who underwent liver stiffness measurement (LSM) and CAP assessment using transient elastography before liver resection between 2019 and 2022 were retrospectively evaluated. Clinical data included body mass index (BMI) and laboratory parameters. The histologically determined hepatic fat fraction (HFF) and fibrosis stages were reviewed by pathologists blinded to clinical and radiologic data. The Pearson correlation coefficient between CAP and HFF was calculated. The diagnostic performance of CAP for significant hepatic steatosis (HFF ≥10%) was assessed using areas under the receiver operating curve (AUCs), stratified by fibrosis stages (F0-1 vs. F2-4). Factors significantly associated with CAP were determined by univariable and multivariable linear regression analyses. Results: Among 399 CHB patients (median age 59 years; 306 men), 16.3% showed significant steatosis. HFF ranged from 0% to 60%. Of these patients, 9.8%, 19.8%, 29.3%, and 41.1% had fibrosis stages F0-1, F2, F3, and F4, respectively. CAP positively correlated with HFF (r=0.445, P<0.001). The AUC of CAP for diagnosing significant steatosis was 0.786 (95% confidence interval [CI], 0.726 to 0.845) overall, and significantly lower in F2-4 (0.772; 95% CI, 0.708 to 0.836) than in F0-1 (0.924; 95% CI, 0.835 to 1.000) (P=0.006). Multivariable analysis showed that BMI (P<0.001) and HFF (P<0.001) significantly affected CAP, whereas LSM and fibrosis stages did not. Conclusion CAP evaluations of significant hepatic steatosis are less reliable in CHB patients with significant or more advanced (F2-4) than with no or mild (F0-1) fibrosis.

Purpose: This study compared the diagnostic performance of two attenuation imaging (ATI) modes—low-frequency (3 MHz) and high-frequency (4 MHz)—for assessing hepatic steatosis, with histopathological hepatic fat fraction (HFF) as the reference standard. Methods: This prospective single-center study enrolled participants with suspected metabolic dysfunction-associated steatotic liver disease (MASLD) scheduled for liver biopsy or surgery between June 2023 and June 2024. Attenuation coefficient (AC) values were consecutively measured using low- and high-frequency ATI modes, while the skin-to-region of interest distance (SRD) was measured simultaneously. Spearman correlation analysis evaluated the relationships of AC with HFF and SRD, and linear regression identified factors affecting AC. Diagnostic performance was evaluated using the area under the receiver operating characteristic curve (AUROC). Results: In total, 119 participants (mean age, 37.2±12.0 years; 87 men) were included, with 73 (61.3%) diagnosed with MASLD. HFF ranged from 0% to 50%. The AC values in the lowfrequency mode were significantly higher than those in the high-frequency mode (0.61 vs. 0.54 dB/cm/MHz, P<0.001). HFF significantly influenced AC in both modes, whereas SRD affected AC only in the high-frequency mode (P<0.001). AC correlated positively with HFF in both modes (r_s≥0.514, P<0.001) and negatively with SRD in the high-frequency mode (r_s=-0.338, P<0.001). The AUROC for hepatic steatosis did not differ significantly between the two modes (0.751 vs. 0.771; P=0.609). Conclusion The low-frequency mode produced higher AC values than the high-frequency mode and demonstrated comparable diagnostic accuracy for assessing hepatic steatosis. Unlike the high-frequency mode, the low-frequency mode was not influenced by SRD.

Background: Infantile hemangioma (IH) is a common benign vascular tumor that occurs during infancy. Oral propranolol is used as a first-line treatment. However, standardized guidelines for evaluating treatment efficacy, particularly the appropriate timing and parameters for Doppler ultrasound (US), have not been established. This study reports on the evaluation of therapeutic efficacy of oral propranolol solution in IH patients using Doppler US, and aims to propose the appropriate timing and parameters for using Doppler US based on this experience. Methods: A retrospective analysis was conducted on 120 patients with IH who were treated with oral propranolol solution and maintained for over 6 months from May 2017 to April 2023. Doppler US evaluation of IH was performed at diagnosis, 1-2 and 6-12 months after treatment initiation, and 6 months post-therapy cessation. A complete response (CR) was identified as a reduction in vascularity along with a decrease in longest diameter (LD) or thickness of 50% or more. Recurrence was evaluated based on increased vascularity or size 6 months after treatment discontinuation. Results: Of 120 patients with IH, 82 females and 38 males were analyzed. IH was first detected at a median age of 12 days (range, 1-240 days), and treatment began at 76 days (range, 27-570 days), continuing for an average of 10.4 months (range, 5-24 months). Initial Doppler US measurements showed an LD of 2.65±1.52 cm and a thickness of 0.79±0.55 cm, with prominent vascularity. After 1-2 months of treatment, LD and thickness decreased by 12.9% and 25.9%, respectively. By 6-12 months, reductions reached 37.2% and 53.6%. CR occurred in 77 patients (64.2%) after 6-12 months of treatment. Eleven patients (9.2%) experienced a recurrence. Conclusion Doppler US is a valuable modality for evaluating the characteristics, treatment response, and recurrence of IH treated with oral propranolol.

Background: The treatment of Kümmell disease (KD) is controversial. Corpectomy and reconstruction or osteotomy with long-level fusion was traditionally performed for the advanced KD. However, these procedures can be disadvantageous for elderly patients.Several alternative surgical procedures including transpedicular intravertebral cage augmentation (TPICA) or vertebroplasty (VP) combined with short-segment fixation (SSF) have been suggested to minimize the surgical burden. This study aimed to compare the outcomes of percutaneous TPICA plus SSF with VP plus SSF for advanced thoracolumbar (T11–L2) KD and to introduce our novel percutaneous TPICA technique using specially designed cannulated cage trials. Methods: We devised specially designed cannulated cage trials to make the TPICA procedure safer and more reproducible, minimizing the risk of the pedicle medial wall violation. All consecutive patients who underwent percutaneous TPICA or VP combined with SSF for advanced thoracolumbar KD, from January 2021 to June 2022, with ≥ 1-year follow-up at a single institution, were included. Perioperative details, clinical outcomes (visual analog scale and Oswestry Disability Index), and radiological outcomes (anterior vertebral body compression percentage and vertebral kyphotic angle [VKA] of the fractured vertebra, and local Cobb angle [LCA]) were collected and compared between the groups. Results: A total of 42 patients were enrolled, with 21 patients in each group. There were no patients with pedicle medial wall fracture in the TPICA group. Both procedures provided significantly favorable radiological outcomes compared to those preoperatively. No significant differences were observed in the changes over time in all radiological parameters between the groups. Loss of correction during the follow-up period was significantly smaller in patients with TPICA than in those with VP in VKA (median [interquartile range], 2.15 [0.30–2.80] vs. 2.90 [0.90–6.53]; p = 0.030) and LCA (2.70 ± 2.90 vs. 5.17 ± 4.40, p = 0.037). Conclusions Both procedures are minimally invasive and useful options for advanced KD, especially for elderly patients with high comorbidity. Our novel percutaneous TPICA technique using cannulated cage trials, being safer and more reproducible, may allow spine surgeons to easily perform TPICA.