Radiology最新文献

Background Diffusion-tensor image (DTI) analysis along the perivascular space (ALPS) is a noninvasive but not well-validated method proposed to evaluate glymphatic function. Purpose To assess ALPS indexes across participant groups and compare them with measures of cerebrospinal fluid (CSF) tracer enrichment and clearance obtained by intrathecal contrast-enhanced MRI (glymphatic MRI [gMRI]). Materials and Methods This secondary analysis of a prospective observational study included participants who underwent clinical work-up for CSF disorders from September 2015 to December 2019. MRI scans were acquired before injection and 24 and 48 hours after intrathecal injection of 0.5 mmol of gadobutrol. DTI scans were preprocessed and segmented using the FMRIB Software Library. Intrathecal contrast-enhanced MRI (ie, gMRI) scans were registered to the baseline T1-weighted image, and cortex and white matter (WM) were segmented with FreeSurfer. ALPS indexes were compared with relative changes in normalized T1-weighted signal intensity at 24 and 48 hours in regions of the cortex, subcortical WM, and deep WM where the ALPS regions of interest are located by using regression analysis. Results A total of 56 participants were included (mean age, 48 years ± 20 [SD]; 36 women): 16 with idiopathic normal pressure hydrocephalus (iNPH), 10 with arachnoid cysts, 11 with idiopathic intracranial hypertension, and 19 reference participants. The ALPS index was lower in the iNPH group than in the reference group (ALPS index, 1.26 and 1.68, respectively; P < .001). Across groups, the ALPS index and degree of CSF tracer enrichment at 24 hours in deep WM were negatively associated (β = -48; P < .001). However, mean tracer enrichment in the ALPS regions of interest was low (10%), in some participants close to 0, whereas enrichment in the cortex ranged from 68% to 81%. Across groups, there was no evidence of associations between the ALPS index and measures of CSF tracer dynamics at 48 hours in any region (|β| ≤ 8; P ≥ .55). Conclusion CSF tracer enhancement in the ALPS regions of interest was sparse across groups, and the association between the ALPS index and gMRI markers of glymphatic function was limited. © The Author(s) 2026. Published by the Radiological Society of North America under a CC BY 4.0 license. Supplemental material is available for this article.

Background Data on the detection of enhancement-related malignant features and applicable scenarios for low-dose ultrahigh-resolution photon-counting CT (PCCT) in lung cancer are lacking. Purpose To compare the benefits of PCCT versus energy-integrating detector (EID) CT at contrast-enhanced chest CT for different populations with lung cancer. Materials and Methods This prospective study enrolled 459 consecutive participants with lesions who underwent either low-dose contrast media PCCT (1 mL/kg at 2 mL/sec) or standard-dose EID CT (1.2 mL/kg at 3 mL/sec) from June to December 2024. The EID CT group was selected using propensity score matching. Images were reconstructed into five section thicknesses (PCCT: 5 mm, 1 mm, 0.4 mm; EID CT: 5 mm, 1 mm). Adverse reactions and contrast-induced acute kidney injury were recorded. Lesion image quality, malignant radiologic features, diagnostic confidence, and subgroup (body mass index [calculated as weight in kilograms divided by height in meters squared], tumor size) were analyzed using a five-point Likert scale. Statistical data were compared using one-way analysis of variance and post hoc comparisons. Results Among 200 participants after propensity score matching (mean age, 61.66 years ± 9.60 [SD]), PCCT reduced radiation and iodine exposure by 66.34% (effective dose, 1.36 mSv vs 4.04 mSv) and 26.57% (iodine load, 20.62 mg vs 28.08 mg; P < .001), respectively, lowering adverse reactions and contrast-induced acute kidney injury (2% [two of 100 participants] vs 9% [nine of 100], P = .03; 1% [one of 100] vs 7% [seven of 100], P = .03). PCCT at 0.4 mm showed higher detection and diagnostic confidence for enhancement-related malignant features (PCCT vs EID CT, 291-340 findings vs 194-255 findings [Likert 5 {IQR, 4-5} vs Likert 3 {IQR, 3-4}]; P < .001) and yielded higher overall image quality (Likert 5 [IQR, 5-5]; P < .05) in normal weight participants and structures within enhanced lesions of less than or equal to 3 cm (Likert 4 [IQR, 3-4] vs Likert 3 [IQR, 3-3]; P < .001). Conclusion PCCT reduced radiation exposure, adverse reactions, and contrast-induced acute kidney injury compared with EID CT. With a 0.4-mm section thickness, PCCT improved overall image quality, detection of enhancement-related malignant features, and diagnostic confidence, making it suitable for various body mass index and small lesions (T1 stage). © The Author(s) 2026. Published by the Radiological Society of North America under a CC BY 4.0 license. Supplemental material is available for this article.

Large language models (LLMs) have transformative potential in radiology, including textual summaries, diagnostic decision support, proofreading, and image analysis. However, the rapid increase in studies investigating these models, along with the lack of standardized LLM-specific reporting practices, affects reproducibility, reliability, and clinical applicability. To address this, reporting guidelines for LLM studies in radiology were developed using a two-step process. First, a systematic review of LLM studies in radiology was conducted across PubMed, IEEE Xplore, and the ACM Digital Library, covering publications between May 2023 and March 2024. Of 511 screened studies, 57 were included to identify relevant aspects for the guidelines. Then, in a Delphi process, 20 international experts developed the final list of items for inclusion. Items consented as relevant were summarized into a structured checklist containing 32 items across six key categories: general information and data input; prompting and fine-tuning; performance metrics; ethics and data transparency; implementation, risks, and limitations; and further/optional aspects. The final FLAIR (Framework for LLM Assessment in Radiology) checklist aims to standardize reporting of LLM studies in radiology, fostering transparency, reproducibility, comparability, and clinical applicability to enhance clinical translation and patient care. © The Author(s) 2026. Published by the Radiological Society of North America under a CC BY 4.0 license. Supplemental material is available for this article.

Background In pediatric biliary cirrhosis secondary to biliary atresia (BA), hepatic lobules are disrupted to form pseudolobules. How the hepatic circulation is reorganized remains a poorly characterized issue. Purpose To reproduce the three-dimensional (3D) structural and remodeling alterations of BA-induced pseudolobules via phase-contrast CT (PCCT) and reveal their circulatory self-rescue mechanism. Materials and Methods In this retrospective study, residual donor normal liver tissue samples and BA-affected liver samples collected between November 2013 and April 2024 were imaged with PCCT. Combined with 3D visualization technology, the spatial anatomic morphologic characteristics of the veins, arteries, and sinusoidal system within the hepatic lobules were reproduced based on liver histopathologic examination. Key indexes such as the number of inlet and outlet venules, sinusoidal volume fraction, and anisotropy, were determined to characterize the structural remodeling of the circulatory pathway, from portal and arterial inflow through the sinusoidal exchange network to hepatic venous outflow, in patients with BA. All indicators were analyzed with generalized estimating equations, and the multiple test correction was performed by conducting Holm-Bonferroni correction, with P < .05 indicating statistical significance. Results Normal livers from three donors (median age, 36 months; IQR, 12-132 months; two male donors) and 25 patients with BA (median age, 7.00 months; IQR, 5.8-10 months; 17 male patients) were analyzed. The mean number of inlet venules decreased from 253.07 ± 70.99 (SD) in normal lobules to 138.80 ± 28.12 in pseudolobules (P < .001). The mean number of inlet arterioles increased from 3.93 ± 1.39 in normal lobules to 5.65 ± 2.43 in pseudolobules (P < .001). The number of outlet venules in pseudolobules decreased by 35% compared with that in normal lobules (mean, 105.02 ± 42.47 vs 161.96 ± 42.47; P < .001). In the sinusoidal system, the volume fraction in pseudolobules increased by 51% compared with that in normal lobules (mean, 40.42 ± 6.28 vs 26.72 ± 6.32; P < .001), especially in the inlet area, where this value nearly doubled (mean, 44.47 ± 4.73 vs 23.44 ± 5.95; P < .001). Mean anisotropy decreased from 0.53 ± 0.02 in normal lobules to 0.51 ± 0.03 in pseudolobules (P < .001). Conclusion The lobular circulation remodeling mechanism in BA-induced pseudolobules, from the inlet channel to the exchange network and outlet channel, was comprehensively revealed via PCCT. © RSNA, 2026 Supplemental material is available for this article.

Background Restenosis is a major cause of stroke recurrence after bare-metal stent (BMS) placement in patients with symptomatic intracranial atherosclerotic disease (ICAD). Observational studies have shown that drug-coated balloon (DCB) angioplasty can reduce restenosis rates. Purpose To compare the efficacy and safety of DCB angioplasty with that of BMS placement in individuals with symptomatic ICAD with high-grade stenosis. Materials and Methods Eligible patients with symptomatic ICAD at 14 Chinese tertiary hospitals were prospectively and randomly assigned (1:1 ratio) to the DCB and BMS groups. The primary outcome was 6-month restenosis assessed with digital subtraction angiography. Secondary and safety outcomes included 6-month symptomatic restenosis, 30-day to 1-year recurrent ischemic event, and 30-day stroke or death. Between-group differences in outcomes were tested using generalized linear and Cox regression models. Results Between July 2021 and March 2023, 209 participants (median age, 59 years [IQR, 52-66 years]; 157 men), 103 and 106 in the DCB and BMS groups, respectively, were included in the intention-to-treat analysis. A total of 164 participants completed the 6-month digital subtraction angiography follow-up, and 203 participants completed the 1-year clinical follow-up. The 6-month angiographic restenosis rate was lower in the DCB group than in the BMS group (11% vs 29%; risk ratio, 0.38 [95% CI: 0.19, 0.78]; P = .006). The DCB group also had a lower 6-month symptomatic restenosis rate (1% vs 10%; risk ratio, 0.13 [95% CI: 0.02, 0.96]; P = .02) and lower 30-day to 1-year recurrent ischemic event rate (4% vs 13%; hazard ratio, 0.31 [95% CI: 0.10, 0.94]; P = .04). The 30-day stroke or death rate was similar in the DCB and BMS groups (6% vs 5%; hazard ratio, 1.24 [95% CI: 0.38, 4.05]; P = .73). Conclusion In individuals with symptomatic ICAD with high-grade stenosis, DCB angioplasty reduced the 6-month risks of angiographic restenosis and symptomatic restenosis and 30-day to 1-year recurrent ischemic event rate compared with BMS placement. Chinese Clinical Trial Registry no. ChiCTR2100046829 © RSNA, 2026 Supplemental material is available for this article. See also the editorial by Wojak in this issue.