Korean Journal of Radiology最新文献

Objective: This study aimed to assess the association between exposure to gadolinium-based contrast agents (GBCAs) and the risk of parkinsonism according to the GBCA type.

Materials and methods: Individuals aged ≥40 years who underwent first-ever magnetic resonance imaging (MRI) examinations between 2011 and 2014 were identified from the Korean nationwide population-based health insurance claims database and followed up until 2022. Individuals were divided into those who underwent at least one GBCA-enhanced MRI, and those who underwent only non-enhanced MRI. GBCA-exposed individuals were further categorized into those exposed only to linear or macrocyclic GBCAs, after excluding those exposed to both types. The primary event of interest was all-cause parkinsonism. Secondary events included all-cause parkinsonism requiring medication, Parkinson's disease (PD), atypical parkinsonism, and secondary parkinsonism. Hazard ratios (HRs) were estimated using multivariable Cox proportional hazard regression models for exposure to linear and macrocyclic GBCAs, with the non-enhanced MRI group serving as a reference. The models were adjusted for age, sex, smoking status, alcohol consumption, regular exercise, body mass index, estimated glomerular filtration rate, and comorbidities. Subgroup analyses were performed according to age, sex, renal function, and history of cancer.

Results: A total of 222,977 individuals were included in this study. Among them, 92,230, 48,335, and 82,412 individuals underwent non-enhanced, linear GBCA-enhanced, and macrocyclic GBCA-enhanced MRI, respectively. Exposure to linear GBCAs slightly increased the risk of all-cause parkinsonism (adjusted HR, 1.13 [97.5% confidence interval, 1.08-1.19]), while exposure to macrocyclic GBCAs did not increase the risk (adjusted HR, 1.00 [97.5% confidence interval, 0.95-1.05]). The results were similar for all-cause parkinsonism requiring medication, PD, and secondary parkinsonism, whereas no significant association was observed for atypical parkinsonism.

Conclusion: Exposure to linear GBCAs may slightly increase the risk of parkinsonism in adults, whereas exposure to macrocyclic GBCAs may not. Caution should be exercised when using linear GBCAs until further evidence emerges.

Objective: To evaluate the feasibility of streamlined radioembolization using yttrium-90 resin microspheres without lung shunt fraction (LSF) assessment in patients with intrahepatic cholangiocarcinoma (ICC).

Materials and methods: This single-center retrospective study included 23 patients with ICC who underwent radioembolization using resin microspheres (SIR-Spheres; SIRTEX, Woburn, MA, USA) without LSF measurement between April 2022 and April 2025. Eligibility criteria, based on prior institutional data, included a target tumor size less than 10 cm, absence of hepatic vein invasion and intratumoral dysmorphic vessels, and an institutional waiting time exceeding one week for macroaggregated albumin scintigraphy. All patients had at least one follow-up imaging study. Radiation activity was prescribed according to tumor location, liver function, and clinical setting, using both single-compartment and multi-compartment dosimetry under the assumptions of a 5% LSF and a tumor-to-normal (TN) ratio of 3. Post-treatment yttrium-90 PET/CT dosimetry was performed in 12 patients. Treatment-related toxicity, tumor response, and local tumor progression-free survival were analyzed.

Results: The median administered activity was 1.43 GBq (interquartile range, 0.89-2.15). The median mean absorbed dose to the perfused tissue was 147 Gy, and the median tumor absorbed dose (TAD) was 339 Gy, assuming a TN ratio of 3. Post-treatment PET/CT analysis demonstrated a median TAD of 371 Gy and a median TN ratio of 4.7. No patient developed symptomatic radiation pneumonitis. Best tumor response was partial response in 52% of patients and stable disease in 48%. Local tumor progression-free survival rates at six months, one year, and two years were 95.2%, 81.1%, and 81.1%, respectively.

Conclusion: Streamlined radioembolization without LSF assessment appears feasible and may represent a practical alternative to conventional multi-step workflows in patients with ICC measuring less than 10 cm.

Metabolic dysfunction-associated steatotic liver disease (MASLD), previously known as nonalcoholic fatty liver disease, is the fastest-growing cause of chronic liver disease worldwide, affecting approximately 30% of the global population. Imaging is vital for detecting, quantifying, and monitoring hepatic steatosis-the defining abnormality of MASLD-and subsequent fibrosis-the key determinant of liver-related outcomes. This review summarizes the principles, clinical usage, efficacy, and advancements in various imaging modalities for the noninvasive assessment of hepatic steatosis and fibrosis, with an emphasis on ultrasound, CT, and MRI. Additionally, this review explores the evolving landscape of MASLD diagnostic approaches, including machine-learning techniques, opportunistic screening, standardized imaging guidelines, and therapies, emphasizing the pivotal role that radiologists can play in shaping these developments.

Objective: This prospective study evaluated the feasibility of chemical exchange saturation transfer (CEST) MRI for assessing disease activity in thyroid-associated ophthalmopathy (TAO).

Materials and methods: A total of 88 patients with active TAO, 76 with inactive TAO, and 30 healthy controls were enrolled. CEST MRI-derived magnetization transfer ratio (MTR) and MTR asymmetry (MTR_asym) at 1 ppm, 2 ppm, and 3.5 ppm were calculated. Clinical data, MTR, and MTR_asym values for the extraocular muscles (one representative muscle per eye, yielding two measurements per participant) were compared among the groups. Spearman's correlation was used to examine associations between imaging parameters and the clinical activity score (CAS) in patients with TAO. Logistic regression analysis was used to identify independent associations between imaging parameters and disease activity in patients with TAO (active vs. inactive). Receiver operating characteristic (ROC) analysis was conducted to evaluate the diagnostic performance for discriminating active from inactive TAO.

Results: Patients with active TAO showed lower MTR values (P < 0.001) and higher MTR_{asym (1 ppm)}, MTR_{asym (2 ppm)}, and MTR_{asym (3.5 ppm)} (all P < 0.001) compared with those with inactive TAO. MTR was negatively correlated with CAS (r = -0.402; P < 0.001), while MTR_{asym (1 ppm)}, MTR_{asym (2 ppm)}, and MTR_{asym (3.5 ppm)} were positively correlated with CAS (r = 0.369, 0.350, and 0.349, respectively; all P < 0.001). MTR and MTR_{asym (1 ppm)} were independently associated with TAO activity. The areas under the ROC curve (AUCs) for MTR and MTR_{asym (1 ppm)} in discriminating active from inactive TAO were 0.772 and 0.730, respectively. Combining MTR with MTR_{asym (1 ppm)} significantly improved diagnostic performance compared with either parameter alone, achieving an AUC of 0.805 (P = 0.029 and 0.001).

Conclusion: MTR and MTR_{asym (1 ppm)} were independently associated with TAO activity. Their combination further enhanced diagnostic performance in distinguishing active from inactive TAO, suggesting their potential as quantitative imaging biomarkers to guide treatment in patients with TAO.