European Radiology Experimental最新文献

{"title":"Combining DMI and [¹⁸F]FDG-PET can complement the assessment of metabolic dysfunction-associated fatty liver disease.","authors":"Viktoria Ehret, Usevalad Ustsinau, Clemens Fürnsinn, Thomas Scherer, Jana Starčuková, Marcus Hacker, Martin Krššák, Cécile Philippe","doi":"10.1186/s41747-026-00724-z","DOIUrl":"10.1186/s41747-026-00724-z","url":null,"abstract":"<p><p>The unique capability of deuterium metabolic imaging (DMI) to detect downstream metabolic products and trace substrates' transport within tissues using conventional magnetic resonance (MR) scanners can, in theory, be employed with routine positron emission tomography (PET)/MR equipment. Our technical proof-of-concept study proposes a protocol for the simultaneous acquisition of DMI and [¹⁸F]FDG-PET data to enable dual assessment of hepatic glucose metabolism. A protocol that integrates high-dose glucose administration, required for DMI, with [¹⁸F]FDG-PET imaging was applied in a spectroscopy-validated rodent model of metabolic dysfunction-associated fatty liver disease (MAFLD). We acquired and quantified high-quality DMI and PET data of the liver that could provide a distinction between healthy and MAFLD cohorts in the future. RELEVANCE STATEMENT: This proof-of-concept study demonstrates the simultaneous DMI-[¹⁸F]FDG-PET acquisition for assessing hepatic glucose metabolism. With its proven viability in healthy and MAFLD livers, hybrid DMI-PET imaging shows promise as a prospective non-invasive tool to improve metabolic disease characterization and support future research applications. KEY POINTS: Simultaneous DMI and [¹⁸F]FDG-PET acquisition is technically feasible on a standard PET/MR system. Hybrid DMI-PET imaging enables dual assessment of hepatic glucose transport and metabolism, offering the advantage of reduced assessment duration. High-dose glucose administration for DMI is compatible with PET imaging, thereby reducing the subject's burden and enhancing liver metabolic evaluation.</p>","PeriodicalId":36926,"journal":{"name":"European Radiology Experimental","volume":"10 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13153327/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147843857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reconstruction algorithms and arm positioning effects on abdominal CT image quality and radiation dose: a phantom study.","authors":"Han Song Mun, Sanghyeok Lim, Shinhyung Kang","doi":"10.1186/s41747-026-00722-1","DOIUrl":"10.1186/s41747-026-00722-1","url":null,"abstract":"<p><strong>Objective: </strong>To evaluate the effects of arm positioning and reconstruction algorithms on radiation dose and image quality of abdominal CT.</p><p><strong>Materials and methods: </strong>Abdominal CT scans were performed using a customized body phantom at 100 kVp with automatic tube current modulation based on noise indices (NI) of 9, 11, and 13 across seven arm positions: arms up (AU), arms down (AD), arms down with one or two-layered air cushions (ADAC, ADAC2), arms on the belly (AB), and arms on the belly with one or two-layered air cushions (ABAC, ABAC2). Images were reconstructed using filtered back projection (FBP), iterative reconstruction, and deep learning-based reconstruction (DLIR). Radiation dose was recorded. Quantitative image quality metrics included image noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), sharpness, and structural similarity. Qualitative assessment of sharpness, noise, artifacts, and overall image quality was performed using fixed-dose AU-FBP images as the reference standard.</p><p><strong>Results: </strong>Compared with the AU position, radiation dose increased by up to 83% in non-AU configurations, with similar trends across all NI settings. In contrast, air cushion use caused only minor, configuration-dependent dose changes. Qualitatively, non-AU FBP images showed marked degradation, whereas DLIR enabled selected non-AU configurations to approach near-reference diagnostic quality. Air cushion-related benefits were modest overall but more apparent in AB than AD configurations.</p><p><strong>Conclusion: </strong>Arm positioning is the primary determinant of radiation dose and image quality in abdominal CT. When arm elevation is not feasible, DLIR effectively mitigates image quality degradation, while air cushions provide limited, configuration-dependent benefits.</p><p><strong>Relevance statement: </strong>When arms cannot be raised during abdominal CT, avoiding arms-on-belly and using air cushions may help maintain image quality without substantially increasing radiation dose, while deep learning image reconstruction further enhances diagnostic performance under restricted positioning conditions.</p><p><strong>Key points: </strong>Arm positioning is a major determinant of radiation dose and image quality in abdominal CT. Arms-on-belly positioning produces poorer image quality despite increased radiation dose. DLIR improves image quality across arm positions but does not eliminate positioning-related degradation.</p>","PeriodicalId":36926,"journal":{"name":"European Radiology Experimental","volume":"10 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13153281/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147843949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lumen imaging in calcified coronary arteries using high-resolution Gd-enhanced color K-edge imaging with spectral photon-counting CT: a phantom study.","authors":"Magdalena M Dobrolinska, Niels van der Werf, Marcel Greuter, Antoine Robert, Marjorie Villien, Hugo Lacombe, Dominika Suchá, Angele Houmeau, Philippe Coulon, Sara Boccalini, Philippe Douek, Salim Si-Mohamed","doi":"10.1186/s41747-026-00720-3","DOIUrl":"10.1186/s41747-026-00720-3","url":null,"abstract":"<p><strong>Objective: </strong>Conventional coronary computed tomography angiography (CCTA) lumen assessment is hampered by the similar attenuation of iodine and calcium. We assessed the lumen for Gd-enhanced CCTA on high-resolution color Gd K-edge imaging using a clinical spectral photon-counting computed tomography (SPCCT) prototype in an anthropomorphic phantom.</p><p><strong>Materials and methods: </strong>A hollow cylindrical coronary artery phantom (10-mm outer diameter, 5-mm inner diameter) containing five cylindrical calcifications of different densities (75, 100, 200, 400, and 800 mg/cm³ hydroxyapatite, deemed very low, low, medium, high, and very high, respectively) and equal size was scanned on a clinical SPCCT prototype using a clinical CCTA protocol. The artery model was filled with Gd mixed with saline to achieve 400 HU at 70 keV. The luminal area was compared with the physical area (i.e., 19.6 mm²), and spectral results were compared to conventional acquisition.</p><p><strong>Results: </strong>In the absence of calcification, physical lumen size was overestimated by 7% and 16% on color Gd K-edge and conventional images, respectively. In the presence of calcification, only color Gd K-edge images enabled the measurement of the lumen, i.e., 22.25 ± 0.43 mm², 22.85 ± 1.77 mm², 14.63 ± 1.17 mm², and 15.37 ± 0.78 for very low to very high calcium density, respectively. Largest underestimation (-26%) and overestimation (16%) were shown for the high- and low-density calcification in comparison to physical size, respectively.</p><p><strong>Conclusion: </strong>Color Gd K-edge imaging with Gd-enhanced CCTA outperformed conventional imaging in assessing the coronary lumen in both noncalcified and calcified vessels, whilst accuracy depends on the presence and density of calcifications.</p><p><strong>Relevance statement: </strong>In a phantom study, high-resolution color Gd K-edge imaging targeting Gd enabled accurate visualization of the coronary lumen in both calcified and noncalcified arteries, outperforming conventional CT angiography. In the presence of calcifications, only color Gd K-edge imaging provided objective lumen assessment, with accuracy influenced by calcium extent and density.</p><p><strong>Key points: </strong>Color Gd K-edge Gd-enhanced CCTA using SPCCT is feasible in a coronary artery phantom. Color Gd K-edge imaging improves lumen assessment in calcified vessels. Color Gd K-edge imaging potentially enhances diagnostic precision and treatment planning for patients with coronary artery disease.</p>","PeriodicalId":36926,"journal":{"name":"European Radiology Experimental","volume":"10 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13149801/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147843999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"9.4-T MRI monitoring of early MASH progression and therapeutic response in a prefibrotic mouse model.","authors":"Yuanyuan Li, Yun Wu, Gengxin Wang, Yanmin Zheng, Haiyang Tong, Hongyi Yang, Jin Yu, Pan Shi, Yong Zheng, Li Zhou, Xin Li, Pei Lv, Changlin Tian","doi":"10.1186/s41747-026-00719-w","DOIUrl":"10.1186/s41747-026-00719-w","url":null,"abstract":"<p><strong>Objective: </strong>Early intervention in metabolic dysfunction-associated steatohepatitis (MASH) is critical to halt disease progression. However, noninvasive tools for monitoring early-stage MASH and therapeutic efficacy in preclinical models remain limited, impeding preclinical drug development. This study establishes an integrated approach using multiparametric magnetic resonance imaging (MRI) at 9.4 T to dynamically track disease development and drug response in a prefibrotic MASH mouse model.</p><p><strong>Materials and methods: </strong>Mice were fed a high-fat and high-cholesterol diet (HFHCD) for 16 weeks to induce early MASH without fibrosis and treated with the anti-MASH drug semaglutide for 8 weeks after modeling. Longitudinal MRI assessments-including proton density fat fraction (PDFF), ¹H magnetic resonance spectroscopy (MRS), T₂ mapping, and diffusion-weighted imaging (DWI)-were performed every 4 weeks and correlated with histopathology.</p><p><strong>Results: </strong>Histology confirmed early MASH after 16 weeks, without fibrosis. All MRI parameters strongly correlated with histopathological scores. HFHCD feeding led to significant changes: PDFF, MRS-derived liver fat content (LFC), and T₂ values increased by 6.8-, 5.2-, and 2.5-fold, respectively, while apparent diffusion coefficient (ADC) decreased by 30% (p < 0.001). T₂ and ADC also correlated with MRS-quantified saturated fatty acids. Semaglutide treatment effectively reversed these changes: PDFF decreased by 73%, LFC by 62%, T₂ by 46% (p < 0.001), and ADC increased 1.4-fold (p = 0.017) compared to the vehicle group.</p><p><strong>Conclusion: </strong>This work demonstrates multiparametric MRI as a powerful noninvasive platform for monitoring early MASH dynamics and treatment response. By enabling longitudinal assessment in a prefibrotic model, this approach accelerates translational research in MASH diagnosis and drug development.</p><p><strong>Relevance statement: </strong>The established multiparametric MRI evaluation system provides a valuable noninvasive monitoring platform for preclinical early-stage MASH research, demonstrating significant potential to accelerate the translational progress in MASH diagnosis and drug development.</p><p><strong>Key points: </strong>A novel prefibrotic MASH model was established to assess early-stage MASH progression. Multiparametric MRI at 9.4 T enables noninvasive, longitudinal monitoring of early MASH. Semaglutide-induced improvement in steatosis and inflammation can be monitored by multiparametric MRI.</p>","PeriodicalId":36926,"journal":{"name":"European Radiology Experimental","volume":"10 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13149678/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147844005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Monitoring carotid arterial stiffness using non-contrast-enhanced 4D MR angiography.","authors":"Isabel Montón Quesada, Thomas Baumgartner, Augustin C Ogier, Jean-Baptiste Ledoux, Robin Ferincz, Jérôme Yerly, Matthias Stuber, Christopher W Roy, Lorenz Hirt, Ruud B van Heeswijk","doi":"10.1186/s41747-026-00716-z","DOIUrl":"10.1186/s41747-026-00716-z","url":null,"abstract":"<p><strong>Objective: </strong>The anatomy of carotid arteries is evaluated with magnetic resonance angiography (MRA), while its stiffness-related parameters are evaluated using ultrasound. An isotropic three-dimensional (3D) MRA technique enabling the measurement of diameter changes could provide a dynamic assessment of the entire carotid tree, extending the existing clinical carotid MR toolset. The goal of this feasibility study was to comprehensively characterize stiffness-related parameters with dynamic 3D MRA and evaluate its repeatability compared to ultrasound.</p><p><strong>Materials and methods: </strong>A non-contrast-enhanced free-running 3D radial MRA sequence was used in 18 healthy volunteers (9 males, 9 females, aged 49 ± 20 years, mean ± standard deviation), scanned twice with both MRA and ultrasound. Diameter changes throughout the cardiac cycle were measured in MRA and ultrasound images to compute stiffness-related parameters: systolic-diastolic relative diameter change (RDC), stiffness index, arterial compliance (AC), local pulse wave velocity and pressure-strain Young's elastic modulus (E), computed for the left (LC) and right (RC) common carotid arteries. Repeatability was evaluated for systolic and diastolic diameter measurements using the intraclass correlation coefficient (ICC). Sub-analyses were performed on a junior and senior subgroup of the volunteers.</p><p><strong>Results: </strong>When evaluating MRA versus ultrasound differences, a relative MRA overestimation of the RDC in the senior cohort (p < 0.001) led to higher AC (p = 0.010) and E (p = 0.042). All stiffness-related parameters were significantly different between the age cohorts. MRA showed high repeatability for the LC (ICC = 0.95) and RC (ICC = 0.93) compared to ultrasound (ICC = 0.78, ICC = 0.51, respectively).</p><p><strong>Conclusion: </strong>Carotid stiffness can be repeatably quantified with non-contrast-enhanced 4D MRA, providing information traditionally obtained with ultrasound.</p><p><strong>Relevance statement: </strong>Dynamic free-running non-contrast-enhanced MRA allows the noninvasive quantification of carotid dynamic properties and anatomy, demonstrating its potential for the assessment of 3D vascular age, showing superior repeatability compared to the clinical standard ultrasound.</p><p><strong>Key points: </strong>Carotid stiffness is assessed with ultrasound and anatomy with MR imaging; combining both assessments in an examination would be valuable. Carotid stiffness can be repeatably quantified with free-running non-contrast-enhanced MRA and yields metrics comparable to ultrasound in healthy volunteers. Dynamic 3D MRA may enable the measurement of stiffness parameters throughout the carotid tree.</p>","PeriodicalId":36926,"journal":{"name":"European Radiology Experimental","volume":"10 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13149800/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147844029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Establishing selection criteria for male New Zealand white rabbits in interventional radiology research using organ volumes and vessel diameters.","authors":"Selma Saclier, Yubei He, Justus Klockner, Lasse Noack, Justus Ramtke, Julius Chapiro, Richard Ruppel, Friederike Hesse, Salma A S Abosabie, Juliane Katharina Unger, Robin Schmidt, Bernhard Gebauer, Lynn Jeanette Savic","doi":"10.1186/s41747-026-00708-z","DOIUrl":"10.1186/s41747-026-00708-z","url":null,"abstract":"<p><strong>Objective: </strong>New Zealand White (NZW) rabbits are widely used in interventional radiology research due to their suitability for human-sized treatment and imaging equipment, offering high translational potential. This study aims to define selection criteria for rabbits by correlating body weight (BW) and age with abdominal organ and vessel dimensions measured on cross-sectional imaging.</p><p><strong>Materials and methods: </strong>Computed tomography and magnetic resonance imaging scans of 80 male NZW rabbits were analyzed using 3D Slicer to measure abdominal organ volumes and vessel diameters. Additionally, an in-house nnU-Net was built for liver volumetry and validated against manual segmentations. Imaging-based measurements were confirmed by gross anatomy in five animals. Statistics included normality testing and Pearson correlation.</p><p><strong>Results: </strong>BW ranged from 2.0 to 4.5 kg (median [IQR]: 3.5 [2.9-3.8]) and age from 10.0 to 24.9 weeks (17.7 [15.0-21.4]); age correlated strongly with BW (p < 0.001). Organ volumes (liver, both kidneys) correlated with BW and age (all p < 0.001), respectively. Additionally, several vessel diameters (left common and internal iliac arteries, inferior vena cava, right common carotid artery) significantly correlated with BW and age, while the celiac trunk (p = 0.010), common hepatic (p = 0.011), and right renal artery (p = 0.031) correlated with BW only. The liver segmentation model achieved a Dice Similarity Coefficient of 0.91.</p><p><strong>Conclusion: </strong>BW and age in NZW rabbits correlate with both organ volumes and large vessels relevant to interventional procedures, supporting the use of biometric data as selection criteria to improve standardization, reduce complications, and enhance preclinical research quality.</p><p><strong>Relevance statement: </strong>Weight- and age-based selection of NZW rabbits improves anatomical suitability for image-guided interventions, enhancing technical success and reproducibility. It may reduce complications and dropouts, avoiding false attribution of adverse events to the technique rather than biometric unsuitability.</p><p><strong>Key points: </strong>Lack of standardized selection criteria in the VX2 rabbit model increases procedural risks and impairs reproducibility in interventional radiology research. Biometric data correlate with organ and vessel dimensions, enabling estimations of anatomical suitability for image-guided procedures in interventional radiological research. This study establishes anatomical reference data providing a quantitative basis to standardize and refine future VX2 rabbit research.</p>","PeriodicalId":36926,"journal":{"name":"European Radiology Experimental","volume":"10 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13125672/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147784029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Artificial intelligence for detecting acute heart failure on chest CT: prospective clinical proof-of-concept validation.","authors":"Kristina Cecilia Miger, Silas Nyboe Ørting, Anne Sophie Overgaard Olesen, Johannes Grand, Mikael Ploug Boesen, Michael Brun Andersen, Jens Petersen, Jens Jakob Thune, Marleen de Bruijne, Olav W Nielsen","doi":"10.1186/s41747-026-00718-x","DOIUrl":"https://doi.org/10.1186/s41747-026-00718-x","url":null,"abstract":"<p><strong>Objective: </strong>Acute heart failure (AHF) is a common but underrecognized cause of dyspnea. Chest computed tomography (CT) can accurately assess pulmonary congestion, but radiologist reporting capacity may limit clinical utility. We hypothesized that an artificial intelligence (AI) model could automatically detect imaging signs of AHF and aimed to prospectively validate an AI model in an independent emergency department cohort, benchmarking its performance against radiologists and cardiologists.</p><p><strong>Materials and methods: </strong>We prospectively validated a supervised machine-learning model in a single-center study of dyspneic patients undergoing low-dose, non-contrast chest CT and echocardiography. The primary analysis assessed diagnostic performance for CT-detected pulmonary congestion compatible with AHF, using radiologist-reported AHF as the reference and the area under the curve at receiver operating characteristic analysis (AUROC). Secondary analyses compared the AI model with blinded research radiologists and expert cardiologists.</p><p><strong>Results: </strong>Of 234 patients (56% males), aged 74 ± 10 years (mean ± standard deviation), 61 (26%) had radiologist-reported AHF. The AI model achieved high diagnostic performance (AUROC 0.95 [95% confidence interval 0.93-0.98]), with 89% sensitivity [78-95] and 89% specificity [83-93]. At prespecified thresholds, rule-out maximized sensitivity (97% [89-100]) at the expense of specificity (74% [67-81]), whereas rule-in yielded high specificity (96% [92-98]) but lower sensitivity (66% [52-77]). In secondary analyses, the AI model achieved a median AUROC of 0.94 (range 0.91-0.96).</p><p><strong>Conclusion: </strong>The AI model demonstrated high diagnostic performance for detecting AHF on chest CT in dyspneic patients. Integration into emergency workflows may support more consistent diagnosis, independent of clinician experience or time constraints.</p><p><strong>Relevance statement: </strong>AI-based analysis of chest CT may enable earlier and more consistent detection of AHF, supporting timely triage and management, especially when specialist radiological expertise is limited or delayed.</p><p><strong>Key points: </strong>An AI model prospectively detected AHF on chest CT in dyspneic emergency department patients. In a prospective single-center cohort, AI achieved high diagnostic performance (AUROC 0.91-0.96), comparable to that of radiologists and cardiologists. AI-based chest CT interpretation may improve diagnostic consistency in the absence of standardized CT criteria for AHF.</p>","PeriodicalId":36926,"journal":{"name":"European Radiology Experimental","volume":"10 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13121664/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147783957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Feasibility of bone-like MRI for acetabular morphology assessment in developmental dysplasia of the hip.","authors":"Tetsuichi Hondera, Yasushi Yoshikawa, Daiho Kasahara, Shota Katsumata, Yoshiaki Hirai, Hisaya Sato","doi":"10.1186/s41747-026-00725-y","DOIUrl":"https://doi.org/10.1186/s41747-026-00725-y","url":null,"abstract":"<p><strong>Objectives: </strong>To evaluate the clinical utility of \"multi-echo recombined gradient echo\" (MERGE)-based bone-like MRI for delineating acetabular osseous morphology in developmental dysplasia of the hip (DDH), and to determine whether this technique provides quantitative measurements with agreement to CT.</p><p><strong>Materials and methods: </strong>This retrospective study included 32 patients with DDH (2 men, 30 women; aged 33 ± 13 years, mean ± standard deviation) who underwent both hip MRI and CT between August 2020 and September 2023. One clinically affected hip per patient was analyzed. The MRI protocol included T1-weighted imaging, short tau inversion-recovery (STIR), and a MERGE sequence with a negative look-up table to enhance bone-like contrast. Joint space width (JSW) and center-edge (CE) angles were measured on all modalities.</p><p><strong>Results: </strong>Mean JSW was 4.2 ± 1.4 mm (T1-weighted), 3.0 ± 1.3 mm (STIR), 3.3 ± 0.9 mm (MERGE), and 3.4 ± 1.1 mm (CT), without a significant difference between MERGE and CT (p = 0.776). Mean CE angles were 29.7 ± 9.5°, 30.9 ± 9.9°, 31.4 ± 10.1°, and 31.4 ± 10.1°, respectively, without significant difference between MERGE and CT (p = 0.908).</p><p><strong>Conclusion: </strong>As an exploratory feasibility study, our findings suggest that MERGE-based bone-like MRI may allow reliable visualization of acetabular morphology and provide quantitative measurements with good agreement to CT. The ability to simultaneously evaluate osseous and soft-tissue structures supports its potential as a radiation-free and comprehensive imaging method for DDH, warranting further validation in larger cohorts.</p><p><strong>Relevance statement: </strong>MERGE-based bone-like MRI enables simultaneous visualization of the hip bone and soft tissues without radiation exposure. This method provides a clinically feasible, MRI-based alternative to CT for evaluating acetabular morphology in DDH.</p><p><strong>Key points: </strong>MERGE-based MR bone-like imaging visualized acetabular morphology and provided CE angle and joint space measurements comparable to CT. MERGE showed the closest agreement with CT for CE angle and joint space, outperforming T1WI and STIR in accuracy. This technique offers radiation-free, comprehensive hip evaluation, serving as a potential MRI-based alternative to CT in DDH assessment.</p>","PeriodicalId":36926,"journal":{"name":"European Radiology Experimental","volume":"10 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13121639/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147783960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Photon-counting CT for dynamic lung perfusion: validation of a low-dose protocol in a porcine lung transplantation model.","authors":"Anna M Hunkemöller, Thomas Werncke, Julian Dittrich, Cornelia Schaefer-Prokop, Franz Söbbeler, Murat Avsar, Jawad Salman, Arjang Ruhparwar, Rainer Blasczyk, Sevval Besli, Constanca Figueiredo, Alicia Enzig-Strohm, Frank K Wacker, Hoen-Oh Shin","doi":"10.1186/s41747-026-00723-0","DOIUrl":"https://doi.org/10.1186/s41747-026-00723-0","url":null,"abstract":"<p><strong>Objective: </strong>Photon-counting CT (PCCT) combines improved dose efficiency with spectral imaging, enabling dynamic functional imaging at chest CT dose levels. Dual energy CT typically uses perfused blood volume (PBV) as a static perfusion surrogate. This study compared low-dose dynamic PCCT compared with reference-dose PCCT and static PBV imaging.</p><p><strong>Materials and methods: </strong>Six minipigs with left lung transplants underwent dynamic perfusion imaging using PCCT at reference and low-dose settings, along with a static PBV scan. Perfusion metrics-Blood Flow Deconvolution (BFD), Mean Transit Time Deconvolution (MTTD), Flow Extraction Product (FEP), and Time to Start Deconvolution (TTSD)-were normalized and analyzed across six lung regions using Kruskal-Wallis tests and Bland-Altman analysis.</p><p><strong>Results: </strong>Low-dose and reference-dose dynamic PCCT showed strong agreement across perfusion parameters (BVP bias: 0.03; BVD bias: 0.04), with no significant differences in BVP (p = 0.995) or BVD (p = 0.374). Kinetic metrics were stable across dose levels (all p > 0.2). While low-dose imaging showed slightly greater perfusion heterogeneity, BVP remained robust. Static PBV differed significantly from dynamic BVP (reference dose: p < 0.001; low-dose: p = 0.04). Left-right perfusion differences were detected in two animals by all methods. Estimated doses were 2.37 mSv (reference-dose) and 1.36 mSv (low-dose), comparable to chest CT (1.49 mSv) and below conventional CT perfusion (3-10 mSv).</p><p><strong>Conclusion: </strong>Dynamic PCCT enables quantitative lung perfusion imaging at radiation doses comparable to standard chest CT. Low-dose dynamic PCCT shows strong agreement with reference-dose acquisitions, while dynamic parameters reveal functional differences not captured by static PBV imaging.</p><p><strong>Relevance statement: </strong>Dynamic low-dose photon-counting computed tomography enables lung perfusion quantification at radiation doses comparable to standard chest CT, facilitating dose-efficient functional imaging in pulmonary disease.</p><p><strong>Key points: </strong>Low-dose PCCT (~ 1.36 mSv) is feasible, comparable to single chest CT (1.49 mSv). Strong agreement was seen between low- and reference-dose PCCT (BVP bias 0.03; BVD bias 0.04). Kinetic perfusion metrics remained stable across dose levels (all p > 0.2).</p>","PeriodicalId":36926,"journal":{"name":"European Radiology Experimental","volume":"10 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13121657/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147784021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cluster habitat-based diffusion MRI radiomics for differentiation of glioblastoma from solitary brain metastasis.","authors":"Wenzheng Luo, Yuanhao Cheng, Changhe Pang, Shenghui Xie, Zhiyue Hao, Yanhao Liu, Mingxue Hu, Xiaoyue Ma, Shanshan Zhao, Mengzhu Wang, Yang Song, Chengxiu Zhang, Yong Zhang, Yang Gao, Guohua Zhao","doi":"10.1186/s41747-026-00717-y","DOIUrl":"https://doi.org/10.1186/s41747-026-00717-y","url":null,"abstract":"<p><strong>Objective: </strong>Given the distinct intratumoral heterogeneity of glioblastoma (GB) and solitary brain metastasis (SBM), habitat-based radiomics derived from neurite orientation dispersion and density imaging (NODDI) may offer enhanced diagnostic value. This study aimed to evaluate NODDI habitat analysis in distinguishing GB from SBM.</p><p><strong>Materials and methods: </strong>This retrospective, two-center study included 279 patients (196 GB, 83 SBM) who underwent 3-T magnetic resonance imaging (MRI), including T1-, T2-, and diffusion-weighted as well as contrast-enhanced T1-weighted sequences. K-means clustering was performed on NODDI images within the region of interest. Following feature extraction, five models were developed: habitat subregion, habitat, radiomics, clinical, and combined. Performance was evaluated using the area under the receiver operating characteristic curve (AUROC), calibration curves, and decision curve analysis.</p><p><strong>Results: </strong>The region of interest was divided into three habitat subregions, with the Habitat-H2 subregion demonstrating strong discriminatory ability (validation AUROC = 0.900; testing AUROC = 0.828). Compared to the radiomics and clinical models, the habitat model containing the three subregions showed a higher discriminatory ability (validation AUROC = 0.929; testing AUROC = 0.851). The combined model, integrating habitat features and clinical variables (age) into a nomogram, achieved the highest predictive performance (validation AUROC = 0.931; testing AUROC = 0.912) and provided superior clinical value.</p><p><strong>Conclusion: </strong>NODDI-based habitat MRI radiomics shows potential for differentiating GB from SBM, while integrating clinical variables is essential for optimal diagnostic performance.</p><p><strong>Relevance statement: </strong>NODDI-based habitat radiomics aids differentiation between glioblastoma and solitary brain metastasis.</p><p><strong>Key points: </strong>Habitat analysis based on NODDI facilitates the differentiation between GB and SBM on MRI. The benefits of habitat analysis are maximized in the three clustered subregions. Habitat radiomics captures intratumoral heterogeneity that whole-tumor radiomics may miss.</p>","PeriodicalId":36926,"journal":{"name":"European Radiology Experimental","volume":"10 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13121666/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147784031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}