Investigative Radiology最新文献

{"title":"Artificial Intelligence-Enhanced Identification of Incidental Findings in Prostate MRI.","authors":"Dominika Skwierawska, Shirin Heidarikahkesh, Dimitrios Bounias, Rafał Jóźwiak, Ihor Horishnyi, Dhrutiv Bhavsar, Tobit Führes, Lorenz A Kapsner, Andrzej Liebert, Hannes Schreiter, Dominique Hadler, Maximilian Bachl, Krzysztof Tupikowski, Michael Uder, Frederik B Laun, Sebastian Bickelhaupt","doi":"10.1097/RLI.0000000000001294","DOIUrl":"https://doi.org/10.1097/RLI.0000000000001294","url":null,"abstract":"<p><strong>Objectives: </strong>The use of prostate magnetic resonance imaging (MRI) is increasing, and coverage often captures substantial portions of the pelvis, visualizing findings outside the prostate gland. The objective of this study was to evaluate the feasibility of automated detection and segmentation of high-prevalence incidental findings in prostate MRI.</p><p><strong>Materials and methods: </strong>This IRB-approved, retrospective study included n=465 prostate MRI examinations (1.5 and 3.0 T), comprising n=315 internal cases from our institution and n=150 external cases from 3 independent data sets. Manual segmentations were performed for perirectal lymph nodes, sigmoid diverticulosis, urinary bladder diverticula, bladder wall thickenings, inguinal hernias, periarticular bone changes of the hip, prominent synovial compartments of the hip, and hydroceles testis on axial T2-weighted (T2w) images for n=265 internal cases (n=520 ROIs). An nnU-Net model was trained on n=213 of these cases. The remaining n=52 independent cases (quantitative test set) were used for the quantitative evaluation of model performance using Dice score, intersection over union (IoU), Hausdorff distance (HD), mean surface distance (MSD), confusion matrices, sensitivity, specificity, and accuracy. Furthermore, n=200 additional examinations (reader test set), comprising n=50 internal, n=150 from 3 independent external data sets, were evaluated by 2 radiologists in an AI-assisted evaluation. Readers assessed the presence of incidental findings (step 1) and the correctness of the nnU-Net-predicted findings (step 2), based on the AI-predicted segmentations.</p><p><strong>Results: </strong>Segmentation performance varied between the incidental findings. Evaluation of the independent quantitative test set revealed that the highest mean Dice scores were achieved for sigmoid diverticulosis (0.80±0.14), hydroceles testis (0.76±0.20), and periarticular bone changes of the hip (0.70±0.07). Radiologists' evaluation of AI predictions on an independent reader test set comprising 1 internal and 3 external data sets demonstrated high agreement in AI-assisted evaluation for most incidental findings. Accuracies per data set (PROSTATEx/Ai4ar/internal/Prostate-3T) were 0.94/0.62/0.96/0.94 for perirectal lymph nodes, 0.82/0.80/0.80/0.84 for sigmoid diverticulosis, 0.86/0.86/0.98/0.98 for urinary bladder diverticula, 0.96/0.82/0.88/0.72 for bladder wall thickenings, 0.94/0.82/0.78/0.86 for inguinal hernias, 0.90/0.80/0.82/0.84 for periarticular bone changes of the hip, 0.90/0.82/0.84/0.96 for prominent synovial compartments of the hip, 0.98/0.80/0.96/0.96 for hydroceles testis. Inter-reader agreement for the AI-assisted evaluation of the presence of incidental findings on T2w images was high, with Cohen κ values ranging from 0.74 to 0.92 for most findings.</p><p><strong>Conclusions: </strong>The nnU-Net-based AI model was able to capture and segment frequent incidental findings in prost","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":""},"PeriodicalIF":8.0,"publicationDate":"2026-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147941575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Relaxivity Performance of Gadopiclenol Versus Gadobenate Dimeglumine In Vitro, and Liver and Brain Imaging: A Randomized Crossover Study.","authors":"Julius F Heidenreich, Daiki Tamada, James Rice, Felix Schön, Garrett C Fullerton, Aaron S Field, Ali Pirasteh, Scott B Reeder","doi":"10.1097/RLI.0000000000001295","DOIUrl":"https://doi.org/10.1097/RLI.0000000000001295","url":null,"abstract":"<p><strong>Objectives: </strong>High-relaxivity macrocyclic gadolinium-based contrast agents (GBCAs) have been introduced to reduce the administered gadolinium dose while maintaining high diagnostic performance. Gadopiclenol exhibits higher intrinsic relaxivity than conventional extracellular agents, but comprehensive evaluation of longitudinal and transverse relaxivity across biologically relevant media and in vivo applications remains limited. The purpose was to compare r1, r2, and r2* relaxivity of gadopiclenol and gadobenate dimeglumine, and to assess dose-dependent in vivo effects in dynamic liver MRI and dynamic susceptibility contrast (DSC) MRI of brain perfusion using a randomized intraindividual crossover design.</p><p><strong>Methods: </strong>Relaxivity was measured in saline, plasma, and whole blood at 1.5T and 3.0T across clinically relevant concentrations. In vivo, participants underwent 3 MRI examinations in a randomized crossover design using 0.05mmol/kg gadopiclenol, 0.1mmol/kg gadopiclenol, and 0.1mmol/kg gadobenate dimeglumine, each separated by ≥28 days. Liver imaging assessed signal enhancement, relative contrast and between-visit residual GBCA effects. DSC perfusion evaluated arterial input function (AIF) metrics and gray-to-white matter relative cerebral blood volume (GM/WM rCBV) ratios.</p><p><strong>Results: </strong>Phantom experiments demonstrated field-dependent and medium-dependent linear relaxivity for all agents and media (R²>0.98), with consistently higher r1, r2, and r2* for gadopiclenol. Liver imaging was performed in 10 participants with focal nodular hyperplasia (7 women; age 20 to 81 y); DSC perfusion imaging was acquired in 10 healthy participants (1 woman, 9 men; age 35 to 77 y). Overall, 60 MRI examinations were performed. Enhancement in the abdomen was comparable between 0.05mmol/kg gadopiclenol and 0.1mmol/kg gadobenate, while 0.1mmol/kg gadopiclenol produced significantly higher liver parenchymal and vascular enhancement. In DSC perfusion imaging, AIF peak and AUC were significantly reduced with 0.05mmol/kg gadopiclenol, whereas 0.1mmol/kg gadopiclenol closely matched gadobenate dimeglumine. Agreement of GM/WM rCBV ratios was high across all protocols despite attenuated first-pass effects.</p><p><strong>Discussion: </strong>0.05mmol/kg gadopiclenol maintains T1-weighted abdominal imaging performance, supporting dose reduction, while higher dosing enhances signal and susceptibility effects. Optimal gadopiclenol dosing appears application-dependent, particularly for DSC perfusion MRI.</p>","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":""},"PeriodicalIF":8.0,"publicationDate":"2026-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147941601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deep Learning-based Automated Coronary Plaque Quantification: First Demonstration With Ultra-high Resolution Photon-counting Detector CT at Different Temporal Resolutions.","authors":"Konstantin Klambauer, Silvan Daniel Burger, Tristan Thorben Demmert, Victor Mergen, Lukas Jakob Moser, Mehmet Akif Gulsun, Max Schöbinger, Chris Schwemmer, Michael Wels, Thomas Allmendinger, Matthias Eberhard, Hatem Alkadhi, Bernhard Schmidt","doi":"10.1097/RLI.0000000000001233","DOIUrl":"10.1097/RLI.0000000000001233","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Objectives: &lt;/strong&gt;The aim of this study was to evaluate the feasibility and reproducibility of a novel deep learning (DL)-based coronary plaque quantification tool with automatic case preparation in patients undergoing ultra-high resolution (UHR) photon-counting detector CT coronary angiography (CCTA), and to assess the influence of temporal resolution on plaque quantification.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Materials and methods: &lt;/strong&gt;In this retrospective single-center study, 45 patients undergoing clinically indicated UHR CCTA were included. In each scan, 2 image data sets were reconstructed: one in the dual-source mode with 66 ms temporal resolution and one simulating a single-source mode with 125 ms temporal resolution. A novel, DL-based algorithm for fully automated coronary segmentation and intensity-based plaque quantification was applied to both data sets in each patient. Plaque volume quantification was performed at the vessel-level for the entire left anterior descending artery (LAD), left circumflex artery (CX), and right coronary artery (RCA), as well as at the lesion-level for the largest coronary plaque in each vessel. Diameter stenosis grade was quantified for the coronary lesion with the greatest longitudinal extent in each vessel. To assess reproducibility, the algorithm was rerun 3 times in 10 randomly selected patients, and all outputs were visually reviewed and confirmed by an expert reader. Paired Wilcoxon signed-rank tests with Benjamini-Hochberg correction were used for statistical comparisons.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;One hundred nineteen out of 135 (88.1%) coronary arteries showed atherosclerotic plaques and were included in the analysis. In the reproducibility analysis, repeated runs of the algorithm yielded identical results across all plaque and lumen measurements ( P &gt; 0.999). All outputs were confirmed to be anatomically correct, visually consistent, and did not require manual correction. At the vessel level, total plaque volumes were higher in the 125 ms reconstructions compared with the 66 ms reconstructions in 28 of 45 patients (62%), with both calcified and noncalcified plaque volumes being higher in 32 (71%) and 28 (62%) patients, respectively. Total plaque volumes in the LAD, CX, and RCA were significantly higher in the 125 ms reconstructions (681.3 vs. 647.8  mm 3 , P  &lt; 0.05). At the lesion level, total plaque volumes were higher in the 125 ms reconstructions in 44 of 45 patients (98%; 447.3 vs. 414.9  mm 3 , P  &lt; 0.001), with both calcified and noncalcified plaque volumes being higher in 42 of 45 patients (93%). The median diameter stenosis grades for all vessels were significantly higher in the 125 ms reconstructions (35.4% vs. 28.1%, P  &lt; 0.01).&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusions: &lt;/strong&gt;This study evaluated a novel DL-based tool with automatic case preparation for quantitative coronary plaque in UHR CCTA data sets. The algorithm was technically robust and reproducible, delivering anatomically consistent","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":"341-349"},"PeriodicalIF":7.9,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13045810/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144954411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Balancing Speed and Sensitivity: Echo-Planar Accelerated MRI for ARIA-H Screening in Anti-Aβ Therapeutics.","authors":"Akifumi Hagiwara","doi":"10.1097/RLI.0000000000001232","DOIUrl":"10.1097/RLI.0000000000001232","url":null,"abstract":"<p><p>The recent advent of anti-amyloid-β monoclonal antibodies has introduced new demands for MRI-based screening of amyloid-related imaging abnormalities, particularly the hemorrhage subtype (ARIA-H). In this editorial, we discuss the study by Loftus and colleagues, which evaluates the diagnostic performance of echo-planar accelerated gradient-recalled echo (GRE) and susceptibility-weighted imaging (SWI) sequences for ARIA-H screening. Their results demonstrate that significant scan time reductions-up to 86%-can be achieved without substantial loss in diagnostic accuracy, particularly for accelerated GRE. These findings align with recently issued MRI guidelines and offer practical solutions for improving workflow efficiency in Alzheimer's care. However, challenges remain in terms of inter-rater variability and image quality, especially with accelerated SWI. We also highlight the emerging role of artificial intelligence-assisted analysis and the importance of reproducibility and data sharing in advancing clinical implementation. Balancing speed and sensitivity remains a central theme in optimizing imaging strategies for antiamyloid therapeutic protocols.</p>","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":"307-308"},"PeriodicalIF":7.9,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144873152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Near-metal MRI Using PETRA With Extended Phase Encoding and Compressed Sensing.","authors":"Ali Caglar Özen, Tobias Stepanek, Shuai Liu, Serhat Ilbey, Tim Hilgenfeld, Thomas Stein, Martin Pichotka, Maximilian Frederik Russe, Stefan Sommer, Reto Sutter, Michael Bock","doi":"10.1097/RLI.0000000000001293","DOIUrl":"https://doi.org/10.1097/RLI.0000000000001293","url":null,"abstract":"<p><strong>Objectives: </strong>To apply compressed sensing (CS) PETRA sequence to MRI near metallic implants, and to investigate the use of an extended phase encoding in csPETRA without significantly increasing the total acquisition time.</p><p><strong>Materials and methods: </strong>Using a 3D realistic model of an orthopedic implant, csPETRA with regular and extended phase encoding was simulated. csPETRA protocols with phase-encoded samples covering from 3.2% to 6.5% of k-space were prepared with a total acquisition time of up to 7±1 minutes and compared to a TSE sequence with VAT and SEMAC in grid phantoms with 3 different total knee arthroplasty implants. In vivo measurements on a patient with a wrist implant and a patient with a knee prosthesis were performed. Quantitative analysis based on the artifact size and qualitative comparison of the tested sequences are presented.</p><p><strong>Results: </strong>In the csPETRA images, geometric distortions were reduced by 40% compared to those in the SEMAC-VAT images. A ratio of 6.5% for the central single-point imaging (SPI) coverage yielded a 20% improvement in artifact size compared to 3.2% coverage, and a 16-fold acceleration reduced the total scan time to 8 minutes.</p><p><strong>Conclusions: </strong>csPETRA with a higher SPI/radial ratio achieves a 20% reduction in artifact size relative to the minimum SPI/radial ratio, that is, conventional PETRA, without a time penalty. In addition, it reduces SAR by a factor of 2.5 compared to SE-based techniques. csPETRA should currently be regarded as a complementary research tool rather than a standalone clinical sequence, with potential niche applications such as high-resolution (0.5 mm isotropic) field mapping and implant assessment, or imaging patients with strict SAR or acoustic-noise constraints, while its clinical value requires further validation together with the development and evaluation of suitable soft-tissue contrast mechanisms.</p>","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":""},"PeriodicalIF":8.0,"publicationDate":"2026-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147771411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spectral Photon-Counting Detector CT for Comprehensive Evaluation of Carotid Plaque and Stenosis.","authors":"Juul Bierens, Jelske Kuijpers, Florentina M E Pinckaers, Luca Saba, Luc J M Smits, Robert J van Oostenbrugge, Thomas Flohr, M Eline Kooi, Alida A Postma","doi":"10.1097/RLI.0000000000001291","DOIUrl":"https://doi.org/10.1097/RLI.0000000000001291","url":null,"abstract":"<p><strong>Background: </strong>Conventional energy-integrating detector (EID) CT is limited in differentiating soft-plaque components due to overlapping attenuation values and is frequently affected by calcification-related blooming artifacts that obscure the vessel lumen and may overestimate stenosis. Photon-counting detector CT (PCD-CT) can provide enhanced spatial resolution and spectral discrimination compared with conventional EID-CT, potentially improving carotid plaque characterization and mitigating artifact-related limitations. This study systematically evaluated image quality, plaque component attenuation, and stenosis visualization across spectral PCD-CT reconstructions.</p><p><strong>Methods: </strong>We retrospectively included patients who underwent PCD-CT for carotid stenosis assessment. Four monoenergetic (ME 40, 55, 70, and 85 keV), PureLumen (PL), and virtual noncontrast (VNC) reconstructions were analyzed. Signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), edge sharpness, plaque area, degree of NASCET stenosis, and attenuation of plaque components (intraplaque hemorrhage, lipid-rich necrotic core, fibrotic tissue, calcification) were compared using repeated-measures ANOVA with Bonferroni correction.</p><p><strong>Results: </strong>Our study included 27 patients (16 men, age: 74.5±9.1 y) with 50 plaques. CNR, SNR, and noise decreased with increasing ME levels ( P <0.001). PL yielded CNR and sharpness comparable to ME55, whereas VNC exhibited a near-zero lumen signal. Stenosis remained consistent across ME reconstructions (44% to 45%, P =1.00), but significantly reduced for PL (38%, P <0.001). Lower-energy reconstructions (ME40/ME55) improved the separation of attenuation values between the lumen and the various plaque components.</p><p><strong>Conclusion: </strong>Low-energy PCD-CT reconstructions enhance CNR and sharpness while maintaining consistent plaque and stenosis measurements. The PL algorithm may improve the assessment of calcified plaques, where conventional reconstructions may overestimate stenosis. PCD-CT shows promise for advanced plaque composition evaluation, but further validation against MRI and histology is warranted.</p>","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":""},"PeriodicalIF":8.0,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147690202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Leveraging the Potential of Ultra-High Resolution Photon Counting Detector CT Angiography of the Cerebral Vasculature by Using Low kVp and Sharp Kernels.","authors":"Florentina M E Pinckaers, Bart A J M Wagemans, Ilse Huijberts, Thomas G Flohr, Joachim E Wildberger, Alida A Postma","doi":"10.1097/RLI.0000000000001285","DOIUrl":"https://doi.org/10.1097/RLI.0000000000001285","url":null,"abstract":"<p><strong>Objectives: </strong>To assess quality improvements in ultra-high resolution (UHR) photon counting detector (PCD) CT angiography (CTA) of the cerebral vasculature using image acquisition at lower kVp and image reconstruction with sharper kernels.</p><p><strong>Materials and methods: </strong>All cerebral CTA imaging on PCD-CT performed over a period of 25 months was evaluated retrospectively. Records were excluded in case of protocol deviations, severe motion artifacts, or cerebral circulatory arrest. Using UHR resolution data acquisition (120×0.2 mm collimation) and reconstruction of polyenergetic (T3D) images at 0.2 mm, 3 subsequent protocols were evaluated: (1) 140 kVp/medium-sharp kernel (Hv40); (2) 90 kVp/Hv40; and (3) 90 kVp/very sharp kernel (Hv72). Virtual monoenergetic 0.4 mm reconstructions were derived at 55 keV using a medium-sharp kernel (Hv40) in protocols 1 and 2 and a sharp kernel (Hv60) in protocol 3. Vessel attenuation, signal-to-noise ratios (SNRs), and contrast-to-noise ratios (CNRs) were derived at 4 locations in the anterior circulation. Vessel sharpness was quantified using the edge rise distance and edge rise slope. Subjective assessments of image noise, vessel attenuation, and vessel sharpness were performed by 2 readers on a 5-point Likert scale.</p><p><strong>Results: </strong>Out of 154 screened patient records, 141 were included. Vessel attenuation, SNR, and CNR improved with image acquisition at 90 kVp compared with 140 kVp for both 0.2 mm T3D images and, to a lesser extent, for 0.4 mm virtual monoenergetic images (VMI) in the protocols using a medium-sharp reconstruction kernel. In the 0.2 mm T3D images, SNR and CNR decreased when applying very sharp kernels at 90 kVp due to an increase in noise. However, SNR and CNR remained stable in small-caliber vessels, whereas both parameters decreased with medium-sharp kernels. Vessel sharpness was markedly improved in the 90 kVp/very sharp kernel protocol. Subjective assessment of image quality also favored the 90 kVp/very sharp kernel protocol. In the 0.4 mm VMI, similar improvements in quantitative and qualitative image quality were observed with image acquisition at 90 kVp (compared with 140 kVp) and image reconstruction using a sharp kernel (compared with a medium-sharp kernel).</p><p><strong>Conclusions: </strong>Image quality of UHR PCD-CTA of the cerebral vasculature is improved with image acquisition at 90 kVp and image reconstruction with (very) sharp kernels.</p>","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":""},"PeriodicalIF":8.0,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147690154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"White and Gray Matter Multiple Sclerosis Spinal Cord Lesion Characteristics and Individualized Tissue Damage Assessment Using 7 T T1 Mapping.","authors":"Nilser Laines-Medina, Samira Mchinda, Benoit Testud, Arnaud Le Troter, Lauriane Pini, Bertrand Audoin, Jean Pelletier, Sarah Demortière, Julien Cohen-Adad, Virginie Callot","doi":"10.1097/RLI.0000000000001288","DOIUrl":"https://doi.org/10.1097/RLI.0000000000001288","url":null,"abstract":"<p><strong>Objectives: </strong>The aim of this exploratory study was to demonstrate how 7 T MP2RAGE T1 mapping can be used to evaluate spinal cord (SC) tissue damage and lesion characteristics in multiple sclerosis (MS) at both subregional and individual levels.</p><p><strong>Materials and methods: </strong>Fifteen patients with relapsing-remitting MS (pwRRMS; mean disease duration = 32 ± 24.9 mo) and 15 age-matched healthy controls (HC) underwent 7 T cervical 3D MP2RAGE imaging with submillimetric spatial resolution. Automatic SC and lesion segmentations were obtained and manually corrected when necessary. Images were registered to the AMU7T template space to extract T1 values from specific regions of interest (ROIs), including white matter (WM) tracts: corticospinal (CST), lateral sensory (LST), posterior sensory (PST), ventral motor (VMT), and gray matter (GM) subregions: ventral, intermediate, and dorsal. Individual Z-score maps were computed and used to derive a global index of tissue impairment (patient-specific Z-score barplot) for lesion and normal appearing tissues (NAT). Finally, MS lesions were further characterized by their relative lesion load (RLL%), frequency maps, and topography across ROIs.</p><p><strong>Results: </strong>Lesions were predominantly located in the posterior half of the cord, with GM showing the highest RLL. However, no lesions were observed exclusively in GM.An increasing gradient in T1 values was observed, with T1_HC <T1_NAT <T1_lesion (P < 0.01). Mixed GM-WM lesions exhibited higher T1 values and larger volumes than WM-only lesions. Elevated T1 values were also detected in NATs of SC lesion-free patients relative to HC, suggesting diffuse microstructural injury beyond visible lesions.The Z-score barplots provided individualized visualization of tissue damage, revealing more than 10% of abnormal SC voxels in 8/15 pwRRMS.</p><p><strong>Conclusion: </strong>This exploratory study demonstrates the potential and sensitivity of 7 T MP2RAGE T1 mapping for characterizing both focal and diffuse WM/GM SC tissue damage in MS. When combined with Z-score metrics, it provides a quantitative and individualized framework for assessing tissue integrity, grading the extent of microstructural impairment, and potentially monitoring neuroprotective treatment effects over time.</p>","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":""},"PeriodicalIF":8.0,"publicationDate":"2026-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147673386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Different Glymphatic-Lymphatic Coupling in the Nasal Mucosa and Parasagittal Dura.","authors":"Horst Urbach, Murat Kavus, Niklas Lützen, Charlotte Zander, Theo Demerath, Alexander Rau, Katharina Wolf, Jürgen Beck, Ikram Eda Duman","doi":"10.1097/RLI.0000000000001220","DOIUrl":"10.1097/RLI.0000000000001220","url":null,"abstract":"<p><strong>Background: </strong>Glymphatic-lymphatic coupling is difficult to visualize in humans.</p><p><strong>Purpose: </strong>To evaluate the transport from the basal subarachnoid space to lymphatic vessels in the nasal mucosa and in the parasagittal dura, respectively.</p><p><strong>Methods: </strong>A highly resolved 3D compressed sensing black blood sequence with almost isotropic resolution (0.5 ×0.5 ×0.6 mm 3 ) was acquired in 26 patients before and 2 to 4, 6 to 8, 24 to 48, and 72 to 96 hours after intrathecal injection of 0.5 mL gadobutrol. T1 signal intensities were measured in CSF spaces (perisylvian, above cribriform plate, midsylvian, and parasagittal), in the olfactory bulbs, fila olfactoria, and nasal mucosa, as well as in the cortex, white matter, and parasagittal dura.</p><p><strong>Results: </strong>In the perisylvian CSF, in the CSF above the cribriform plate, in the olfactory bulbs, fila olfactoria, nasal mucosa, and in the cortex, percentage T1 signal intensities showed a rapid increase, peaking at 2 to 4 hours and 6 to 8 hours, respectively. The midsylvian and parasagittal CSF exhibited a slower increase with peak enhancement at 24 to 48 hours. Similarly, in the white matter of the temporal lobe, T1 signal intensities increased gradually, reaching their peak at 24 to 48 hours, followed by a decline after 72 to 96 hours. In the parasagittal dura, T1 signal intensities continued to rise even beyond 72 to 96 hours.</p><p><strong>Conclusions: </strong>Intrathecally injected gadolinium reaches the lymphatic vessels in the nasal mucosa earlier than those in the parasagittal dura. Transport to the nasal mucosa takes place directly via the subarachnoid space. For the transport to the parasagittal dura, findings are compatible with a trans-parenchymal transport route.</p>","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":"234-240"},"PeriodicalIF":7.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144527975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diagnostic Value of Contrast-Enhanced Ultrasound in Renal Masses Remaining Indeterminate After Contrast-Enhanced CT and Contrast-Enhanced MRI.","authors":"Aurélie O'Keane, François Audenet, Virginie Verkarre, Jean-Michel Correas, Olivier Hélénon, Sylvain Bodard","doi":"10.1097/RLI.0000000000001223","DOIUrl":"10.1097/RLI.0000000000001223","url":null,"abstract":"<p><strong>Objectives: </strong>Some renal masses remain indeterminate after both contrast-enhanced CT (CE-CT) and contrast-enhanced MRI (CE-MRI), with uncertainty concerning their cystic or solid composition, raising an issue in patient management. The aim of this article was to assess the diagnostic performance of contrast-enhanced ultrasound (CEUS) in the characterization of indeterminate renal masses in this specific context.</p><p><strong>Materials and methods: </strong>Starting from CEUS examinations investigating renal masses, we retrospectively identified patients with renal masses that remained indeterminate after both unenhanced and enhanced CT and MRI. CEUS examinations were performed in a single center between February 2009 and September 2019. Cross-sectional imaging and nonenhanced US images were individually reviewed to confirm each lesion's indeterminate nature. CEUS was performed to differentiate solid and cystic lesions. CEUS findings were correlated to pathologic analysis or follow-up (minimum 3 y) to assess diagnostic performance. Inter-reader agreement was also analyzed.</p><p><strong>Results: </strong>Sixty-four patients [mean age: 60.5±12.1 (SD), 49 men; 15 women] with 73 indeterminate renal masses (median: 24 mm, range: 10 to 122 mm) were identified. CEUS enabled further characterization of 71 out of the 73 indeterminate lesions (97.3%). To establish the solid nature of a renal mass, CEUS had a sensitivity of 81.3% (95% CI: 54.5%-95.9%), a specificity of 98.2% (95% CI: 90.3%-99.9%), a positive predictive value of 92.9% (95% CI: 64.8%-98.9%), a negative predictive value of 94.7% (95% CI: 86.6%-98.0%), and an accuracy of 94.4% (95% CI: 86.2%-98.4%), with excellent inter-reader agreement.</p><p><strong>Conclusion: </strong>CEUS can accurately distinguish solid from cystic lesions in renal masses indeterminate after CE-CT and CE-MRI.</p>","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":"225-233"},"PeriodicalIF":7.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144799073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}