Korean Journal of Radiology最新文献

Objective: To evaluate and compare scan times, measurement accuracy, and image quality (IQ) of free-breathing (FB) and breath-hold (BH) deep learning (DL) cine MRI sequences versus standard cine MRI, with a specific focus on patients with arrhythmia and dyspnea.

Materials and methods: Seventy participants were prospectively enrolled, including 24 with arrhythmia, 17 with dyspnea, and 29 with normal sinus rhythm and eupnea (mean age, 49 ± 17 years). Each patient underwent three cine MRI acquisitions (standard cine, BHDL, and FBDL) on a 3T scanner. Quantitative assessments of biventricular function, left ventricular mass, and myocardial strain were independently performed by three radiologists, blinded to image acquisition techniques. IQ was evaluated by the same readers using both a five-point Likert scale and objective metrics.

Results: Both BHDL and FBDL significantly reduced total examination times compared to standard cine (BHDL: 58 ± 5 s; FBDL: 88 ± 12 s; standard cine: 208 ± 12 s; adjusted P < 0.001). Quantitative measurements from BHDL and FBDL showed no statistically significant differences compared to standard cine and showed strong correlations (correlation coefficients > 0.85) with standard cine. BHDL consistently demonstrated narrower 95% limits of agreement (LOA) than FBDL across all parameters. For BHDL, the 95% LOA for left and right ventricular ejection fractions were -3.5% to 3.9% and -3.4% to 4.0%, respectively; for FBDL, they were -4.6% to 5.8% and -7.8% to 9.3%, respectively. In patients with arrhythmia, BHDL achieved significantly higher IQ Likert scores (4.44 ± 0.56) than both standard cine (4.00 ± 0.99; adjusted P = 0.043) and FBDL (3.94 ± 0.56; adjusted P = 0.030). In patients with dyspnea, FBDL received the highest IQ scores (4.24 ± 0.47), outperforming standard cine (3.41 ± 0.97; adjusted P = 0.028) and BHDL (3.68 ± 0.56; adjusted P = 0.028).

Conclusion: Both FBDL and BHDL significantly reduced scan times compared to standard cine without compromising quantitative measurement accuracy. BHDL offered superior measurement accuracy and shorter scan time than FBDL. Furthermore, BHDL demonstrated robust suitability for patients with arrhythmia by minimizing arrhythmia-related artifacts, whereas FBDL was more effective in patients with dyspnea by mitigating respiratory motion artifacts.

Objective: To retrospectively evaluate the diagnostic potential of the peritumoral cortex low-enhancement (PCLE) sign on corticomedullary phase (CMP) CT images for differentiating malignant from benign lesions and clear cell renal cell carcinoma (ccRCC) from non-ccRCC among small renal masses (SRMs, ≤4 cm).

Materials and methods: After excluding cases with incomplete/poor-quality CT images and SRMs exhibiting cystic changes, visible fat, or infiltrative/completely endophytic/exophytic growth patterns, 603 histopathologically confirmed SRMs (507 malignant and 96 benign; 409 ccRCC and 194 non-ccRCC) from 595 patients across three institutions were retrospectively analyzed using thin-slice CT images (≤1.5 mm). PCLE was defined as a focal low-enhancement region of the peritumoral cortex at the tumor-cortex interface on CMP CT images, similar to the early dark cortical band sign. Diagnostic performance of PCLE for malignancy and ccRCC was evaluated. A separate cohort of 109 SRMs (91 malignant and 18 benign; 77 ccRCCs and 32 non-ccRCCs) from 108 patients, imaged with thick-slice CT (3 mm), was additionally analyzed using otherwise the same methodology.

Results: PCLE was identified in 331 SRMs (54.9%, 331/603), including 326 malignant and 5 benign SRMs (all oncocytomas >3 cm), and in 307 ccRCC and 24 non-ccRCC SRMs. For diagnosing malignant SRMs, PCLE demonstrated a sensitivity of 64.3% (326/507) and specificity of 94.8% (91/96). For ccRCCs, these values were 75.1% (307/409) and 87.6% (170/194), respectively. In tumors ≤3 cm, specificity reached 100% (78/78) for malignancies and 93.5% (129/138) for ccRCCs. Inter-observer agreement for PCLE was substantial (Cohen's kappa, 0.783). Findings from the thick-slice cohort closely mirrored those in the primary cohort obtained using thin-slice CT images.

Conclusion: PCLE observed on CMP CT demonstrated exceptional specificity for malignant and ccRCC among SRMs, especially in SRMs ≤3 cm, though sensitivity was limited, and false positives occurred in oncocytomas.

Objective: To evaluate the incidence and risk factors of acute adverse drug reactions (ADRs) to nonionic low-osmolar iodinated contrast media (LOCM) in a pediatric population.

Materials and methods: This single-center retrospective study included consecutive data on nonionic LOCM injections in pediatric patients (≤18 years) between January 1, 2016, and June 30, 2023. The per-examination incidences of acute ADRs (physiologic and allergic-like reactions) were assessed along with their severities. Multivariable Poisson regression analysis with generalized estimating equations was used to explore the risk factors associated with the occurrence of each ADR type.

Results: Among 23,429 injections administered to 13,172 pediatric patients, acute allergic-like reactions occurred in 0.89% (208/23,429) of cases, most of which were mild (0.79%; 186/23,429). Acute physiologic reactions occurred in 0.55% (128/23,429), also predominantly mild (0.50%, 118/23,429). Both types of ADRs occurred slightly more frequently in older patients (allergic-like reactions: adjusted relative risk (RR) = 1.09 per 1-year increase [95% confidence interval {CI}: 1.06, 1.11], P < 0.001; physiologic reactions: adjusted RR = 1.04 per 1-year increase [95% CI: 1.01, 1.07], P = 0.008) and more frequently in those with a history of such reactions (allergic-like reactions = 3.62 [95% CI: 1.44, 9.09], P = 0.006; physiologic reactions = 7.44 [95% CI: 2.55, 21.70], P < 0.001). Acute allergic-like reactions occurred less frequently in inpatient/emergency settings than in outpatient settings (adjusted RR = 0.64 [95% CI: 0.48, 0.85], P = 0.002). Among the 226 examinations with prior allergic-like reactions, recurrent acute allergic-like reactions occurred in 7.26% (9/124) when re-exposed to the same generic LOCM and in 3.92% (4/102) when exposed to a different generic LOCM (P = 0.28). Moderate reactions occurred in three cases that were re-exposed to the same LOCM, whereas all four reactions with different LOCM were mild.

Conclusion: Acute allergic-like and physiologic reactions to nonionic LOCM occurred in 0.89% and 0.55% of cases, respectively. Older age and a history of prior reactions were significant risk factors. Particular care is warranted during contrast-enhanced CT in these high-risk groups.

Objective: To assess the role and treatment response of percutaneous lymphatic embolization performed for non-traumatic chylothorax in patients with Gorham-Stout disease (GSD) with regard to thoracic duct embolization (TDE) and embolization of pleural or lymphatic collaterals.

Materials and methods: This retrospective single-institution study included consecutive patients who underwent percutaneous lymphatic embolization between January 2013 and December 2022. The patients underwent dynamic contrast-enhanced magnetic resonance lymphangiography, fluoroscopic intranodal lymphangiography, or both to evaluate the lymphatic anatomy prior to the intervention. The patients underwent TDE, pleural lymphatic embolization, or both, depending on the imaging findings. The data collected included imaging findings, procedural details, and clinical outcomes (clinical success was defined as removal of the drainage catheter without re-accumulation of effusion or improvement in clinical symptoms).

Results: Five male patients (aged 5-29 years) with chylothorax (n = 3) or hemorrhagic chylothorax (n = 2) were included. The key imaging findings included giant thoracic duct (n = 3) and dilated parietal pleural lymphatic system (n = 5). Twelve embolization sessions were performed (median, 2 sessions per patient; range 1-4 sessions). The embolized lymphatic structures included the thoracic duct (n = 4), parietal pleural lymphatics (n = 4), and other lymphatic collaterals (n = 3). The embolic agents used were glue and coils (n = 3), and glue only (n = 2). TDE alone achieved clinical success in only 25% of the cases (1 out of 4). With additional embolization of the parietal pleural lymphatics and other collaterals, clinical success was achieved in 80% of the cases (4 out of 5). One patient developed chylous ascites after the TDE.

Conclusion: Percutaneous lymphatic embolization targeting the thoracic duct and pleural lymphatic collaterals is a feasible treatment option for GSD-related chylothorax.

Multimodal large language models (MLLMs) are emerging as powerful tools in medicine, particularly in radiology, with the potential to serve as trusted artificial intelligence (AI) partners for clinicians. In radiology, these models integrate large language models (LLMs) with diverse multimodal data sources by combining clinical information and text with radiologic images of various modalities, ranging from 2D chest X-rays to 3D CT/MRI. Methods for achieving this multimodal integration are rapidly evolving, and the high performance of freely available LLMs may further accelerate MLLM development. Current applications of MLLMs now span automatic generation of preliminary radiology report, visual question answering, and interactive diagnostic support. Despite these promising capabilities, several significant challenges hinder widespread clinical adoption. MLLMs require access to large-scale, high-quality multimodal datasets, which are scarce in the medical domain. Risks of hallucinated findings, lack of transparency in decision-making processes, and high computational demands further complicate implementation. This review summarizes the current capabilities and limitations of MLLMs in medicine-particularly in radiology-and outlines key directions for future research. Critical areas include incorporating region-grounded reasoning to link model outputs to specific image regions, developing robust foundation models pre-trained on large-scale medical datasets, and establishing strategies for the safe and effective integration of MLLMs into clinical practice.

Antibody-drug conjugates (ADCs) have revolutionized the treatment landscape for advanced bladder cancer, particularly enfortumab vedotin and trastuzumab deruxtecan, which target Nectin-4 and human epidermal growth factor receptor 2 (HER 2), respectively. These ADCs have shown substantial efficacy, improving survival in patients who have progressed after chemotherapy and immunotherapy. Imaging plays a pivotal role in ADC-based therapy, extending beyond diagnosis and staging to assessing treatment response, detecting recurrence, and evaluating toxicity. Computed tomography (CT), multiparametric magnetic resonance imaging (MRI), and fluorodeoxyglucose positron emission tomography (FDG-PET) are widely used for these purposes. Despite the efficacy of ADCs, resistance mechanisms such as antigen loss and payload resistance continue to pose challenges, necessitating the development of next-generation ADCs. Response assessment largely relies on Response Evaluation Criteria in Solid Tumors (RECIST) 1.1, with growing interest in multiparametric MRI for evaluating complete response in bladder lesions. Additionally, imaging helps identify ADC-related toxicities, including pneumonitis and gastrointestinal complications. Radiologists must be aware of these evolving therapeutic and imaging paradigms to optimize patient management. The integration of imaging with ADC-based treatment requires a multidisciplinary approach to improve outcomes. This review highlights the critical role of imaging in ADC therapy and underscores the need for radiologists to adapt to these advancements in bladder cancer treatment.