Investigative Radiology最新文献

{"title":"Improved Visualization of Heart Valves With 4D-CT Using a Novel Motion Correction Algorithm.","authors":"Daniel Zedler, Tristan T Demmert, André Ritter, Thomas Allmendinger, Bernhard Schmidt, Albert M Kasel, Omer Dzemali, Robert Manka, Victor Mergen, Thomas Flohr, Matthias Eberhard, Hatem Alkadhi","doi":"10.1097/RLI.0000000000001310","DOIUrl":"https://doi.org/10.1097/RLI.0000000000001310","url":null,"abstract":"<p><strong>Objective: </strong>Motion artifacts remain a limitation of cardiac CT when assessing both native and prosthetic heart valves, particularly during phases of rapid motion. This may lead to reduced image quality, potentially impairing the evaluation of valvular movement and pathology. The purpose of this study was to evaluate whether a novel reconstruction-based motion correction algorithm improves image quality and reduces motion artifacts of native and prosthetic heart valves compared with standard reconstructions in photon-counting detector CT (PCD-CT).</p><p><strong>Materials and methods: </strong>In this retrospective single-center study, 57 patients [21 women; median age, 71 (interquartile range, 57 to 78 y)] who underwent clinically indicated 4D cardiac CT for suspected native and prosthetic valvular disease were included. Images were acquired using retrospectively electrocardiography (ECG)-gated spiral dual-source PCD-CT without ECG-pulsing. Images were reconstructed in 10% steps throughout the RR-interval using both standard (TrueStack) and an otherwise identical reconstruction using the novel motion correction algorithm (ZeeFreePlus). Subjective image quality and motion artifacts were independently assessed by 2 blinded, experienced readers using a 4-point visual analog scale for 3 categories: valve frame/annulus, valve leaflets, and valvular pathology. Objective analysis included quantification of the volume of artifacts throughout the cardiac cycle.</p><p><strong>Results: </strong>A total of 68 valves were evaluated, including 57 prosthetic valves (22 transcatheter aortic valve replacements and 19 surgical valves, 11 mitral valves, and 5 tricuspid valve interventions) and 11 native valves. Valvular pathology was present in 29 cases, with the most prevalent being hypoattenuated leaflet thickening in 14/29 (48%). Motion-corrected reconstructions significantly improved image quality and reduced motion artifacts across all cardiac phases and all categories (all, P<0.001). The largest improvements were observed during systole, particularly at 10% of the RR-interval, with significantly greater gains than during diastole (P<0.05). Improvements were consistent across aortic and atrioventricular prosthetic valves and translated into improved visualization of valvular pathology (P<0.001). Objective quantitative analysis corroborated the subjective image quality findings by demonstrating reductions in the volumes of motion-induced artifacts when using the algorithm (P<0.001).</p><p><strong>Conclusions: </strong>A novel motion correction algorithm substantially reduced motion artifacts and improved image quality in both native and prosthetic heart valve imaging with PCD-CT, with the largest improvements in systole. These benefits resulted in enhanced visualization of valvular pathology, potentially reinforcing the growing clinical role of cardiac CT for the assessment of valve disease.</p>","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":""},"PeriodicalIF":7.9,"publicationDate":"2026-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149170645","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":"The Effect of Different Gadolinium Delivery Rates on Objective and Subjective Image Quality in Cardiac Perfusion Magnetic Resonance Imaging.","authors":"Casper Mihl, Joey Cjg Pernot, Bjorn Winkens, Martijn W Smulders, Joachim E Wildberger, Robert J Holtackers, Bibi Martens","doi":"10.1097/RLI.0000000000001317","DOIUrl":"https://doi.org/10.1097/RLI.0000000000001317","url":null,"abstract":"<p><strong>Background: </strong>Stress perfusion cardiac magnetic resonance imaging (MRI) enables accurate detection of myocardial ischemia. While contrast injection parameters, particularly iodine delivery rate, are known to influence image quality in CT, their impact in cardiac MRI remains insufficiently studied. This study aimed to evaluate the effect of different gadolinium-based contrast agent (GBCA) injection rates on objective and subjective image quality in perfusion cardiac MRI in patients with suspected ischemic heart disease.</p><p><strong>Methods: </strong>Ninety patients scheduled for a stress perfusion cardiac MRI were retrospectively included and allocated to 3 groups based on the GBCA injection rate used (eg, group 1: 6 mL/s, group 2: 4 mL/s, and group 3: 2 mL/s). Blood-pool signal intensity was extracted on a frame-by-frame basis to generate signal-intensity time curves. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated for all relevant regions, including SNRischemia, SNRblood, SNRmyocardium, CNRischemia-blood, CNRmyocardium-blood, and CNRischemia-myocardium. Subjective image quality was scored on a 5-point Likert scale, blindly assessed in consensus by 2 cardiovascular radiologists.</p><p><strong>Results: </strong>Blood-pool peak intensity was the highest in the group with flow rates of 6 mL/s. Peak signal intensity was for the 6, 4, and 2 mL/s group, respectively, 17525±3616, 15213±3416, and 15534±2990 a.u. (P=0.019) and post hoc comparison demonstrated a significant difference between the 6 mL/s and 4 mL/s group (P=0.027). No significant differences in signal intensity of the myocardium, blood pool and the infarcted region were found between groups (P=0.475, 0.399 and 0.519, respectively). Image noise was significantly higher in group 1 compared to group 3 (P value=0.036). SNR of myocardium, blood, and ischemia was not significantly different between groups (P=0.525, 0.595, and 0.453, respectively). CNR for ischemia-blood, myocardium-blood and ischemia-myocardium were the highest in group 3, but not significantly different (P=0.373, 0.896, and 0.346, respectively). Subjective image quality and reader confidence were not significantly different between groups (P values of 0.985 and 0.842). Although contrast quality demonstrated a statistically significant difference across groups (P=0.026), this finding was not considered clinically relevant.</p><p><strong>Conclusion: </strong>Higher GBCA injection rates resulted in higher blood-pool peak enhancement, yet did not translate into significant differences in objective image and subjective image quality. Lower injection rates appear sufficient to achieve adequate myocardial perfusion imaging, suggesting a plateau in image quality in which increasing flow rates do not show added benefit.</p>","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":""},"PeriodicalIF":7.9,"publicationDate":"2026-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149136565","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":"Gadopiclenol for Cardiac MRI: Comparison of Myocardial T1 Relaxation Times and Subjective Image Quality at Different Doses in Patients With Anderson-Fabry Disease.","authors":"Alena T Kollmann, Henner Huflage, Ramin S Dazeh, Thorsten A Bley, Viktor Hartung","doi":"10.1097/RLI.0000000000001314","DOIUrl":"https://doi.org/10.1097/RLI.0000000000001314","url":null,"abstract":"<p><strong>Objectives: </strong>Due to its high relaxivity, the second-generation gadolinium-based contrast agent gadopiclenol has been shown to provide equally high image quality with reduced gadolinium dose. Gadopiclenol has not yet been approved for cardiac magnetic resonance imaging (CMR). The aim of this observational feasibility study was to assess late gadolinium enhancement (LGE) image quality and myocardial T1 shortening after application of gadopiclenol at 2 dose levels in patients with Anderson-Fabry disease (AFD) undergoing 3 T CMR.</p><p><strong>Materials and methods: </strong>In this retrospective single-center study, 133 CMR examinations were screened, and 32 patients met the eligibility criteria of AFD, gadopiclenol administration, documented contrast dose, and complete precontrast and postcontrast T1 mapping. Patients were grouped by dose (0.05 mmol/kg group, ranging from 0.04 to 0.07 mmol/kg vs. 0.1 mmol/kg group, ranging from 0.08 to 0.11 mmol/kg; n=16 each). Three readers independently rated LGE image quality using a 5-point Likert scale. Quantitative analysis included precontrast and postcontrast myocardial T1, ΔT1, and the relaxation rate ΔR1. Segment-level postcontrast effects were analyzed using a mixed-effects model adjusting for acquisition delay.</p><p><strong>Results: </strong>Both dose levels, the 0.05 mmol/kg and the 0.1 mmol/kg gadopiclenol, resulted in diagnostic examinations with high subjective LGE image quality. The 0.1 mmol/kg group showed slightly higher ratings for overall image quality and bloodpool-to-myocardium contrast, although absolute differences were small and most examinations in the 0.05 mmol/kg group were still rated good to excellent. Native myocardial T1 did not differ between groups (1132.39±61.91 ms vs. 1132.84±53.39 ms; P=0.98). Postcontrast T1 shortening was greater at 0.1 mmol/kg. In segment-level analysis, the higher dose showed greater ΔR1 in all segments, which was statistically significant in unaffected segments (Δ=-0.37 1/s; P=0.003), but not in affected segments (Δ=-0.18 1/s; P=0.48).</p><p><strong>Conclusions: </strong>In this retrospective 3 T AFD cohort, gadopiclenol provided high LGE image quality at both dose levels. While 0.1 mmol/kg produced slightly stronger qualitative and quantitative contrast effects, 0.05 mmol/kg remained technically feasible. These preliminary findings support that dose reduction to 0.05 mmol/kg gadopiclenol may be feasible in CMR. However, validation through prospective studies is needed before recommending lower-dose gadopiclenol broadly in routine CMR.</p>","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":""},"PeriodicalIF":7.9,"publicationDate":"2026-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149038593","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":"Gadolinium-based Contrast Agents Trigger Gadolinium Accumulation Within the Hippocampus In Vivo and Mitochondrial Alterations in Organotypic Hippocampal Tissue Cultures Ex Vivo.","authors":"Rebecca Ludwig, Mathias Schannor, Heike Traub, Carmen Infante-Duarte, Lina Anderhalten","doi":"10.1097/RLI.0000000000001315","DOIUrl":"10.1097/RLI.0000000000001315","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Background: &lt;/strong&gt;In multiple sclerosis (MS), mitochondrial dysfunction contributes to disease progression and may impair cognitive function, particularly in vulnerable regions such as the hippocampus. Gadolinium-based contrast agents (GBCAs) are widely used for imaging-based diagnosis of MS; however, evidence indicates that gadolinium (Gd) can be released from low-stability agents and retained in the brain. Whether retained Gd affects neuronal mitochondria, particularly under inflammatory conditions, remains unclear. We investigated hippocampal Gd retention following in vivo GBCA exposure and assessed associated mitochondrial effects in hippocampal slice cultures.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;Mice with experimental autoimmune encephalomyelitis (EAE) and healthy controls received repeated injections of linear gadopentetate-dimeglumine (gadopentetate) or macrocyclic gadobutrol (cumulative dose: 20 mmol/kg body weight). Hippocampal Gd distribution and retention kinetics were analyzed 1, 10, and 40 days post-final injection (p.f.i.) using laser ablation inductively coupled plasma-time-of-flight mass spectrometry (LA-ICP-ToF-MS). Ex vivo, organotypic hippocampal slice cultures from B6.Cg-Tg(Thy1-CFP/COX8A)S2Lich/J mice expressing fluorescently labeled neuronal mitochondria were exposed to TNF-alpha (paradigm of inflammation)±gadopentetate or gadobutrol for 48 hours (0.1, 1, 10, 50 mM). Mitochondrial dynamics were quantified using semi-automated and manual analyses of confocal microscopy images, and Gd slice content was determined by ICP-MS.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;In vivo, neuroinflammation increased hippocampal Gd accumulation following administration of both GBCAs in EAE mice. However, long-term retention up to 40 days p.f.i. was observed exclusively for gadopentetate, particularly in EAE mice. Ex vivo, prolonged exposure to both GBCAs at low-to-intermediate concentrations (0.1 to 10 mM) reduced mitochondrial length and area, particularly under inflammatory conditions, and altered mitochondrial motility relative to untreated controls. At these concentrations, intratissue Gd levels, quantified by ICP-MS under representative conditions, were within a biologically relevant, sub-cytotoxic range. Marked motility impairment and mitochondrial rounding occurred only at the highest gadopentetate concentration (50 mM). Interestingly, although inflammation did not alter Gd concentrations within the ex vivo slices, mitochondrial alterations were more pronounced under inflammatory conditions.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusion: &lt;/strong&gt;In the hippocampus, long-term Gd retention in vivo appears to be restricted to linear GBCAs, whereas ex vivo, exposure to both linear and macrocyclic GBCAs at biologically relevant concentrations alters neuronal mitochondrial morphology and dynamics. Inflammation further amplifies these effects, highlighting the importance of considering GBCA-associated mitochondrial damage when evaluating their potential neurotox","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":""},"PeriodicalIF":7.9,"publicationDate":"2026-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149012231","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":"Influence of X-ray Tube Voltage on Computed Tomography Values and Contrast-Noise Ratios in Virtual Monoenergetic Images in routine clinical Photon Counting Detector Computed Tomography: Does kV Still Matter?","authors":"Cécile R L P N Jeukens, Florentina M E Pinckaers, Bibi Martens, Sören Jasper, Joachim E Wildberger, Thomas Flohr","doi":"10.1097/RLI.0000000000001312","DOIUrl":"https://doi.org/10.1097/RLI.0000000000001312","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Purpose: &lt;/strong&gt;Conventional energy integrating detector (EID) CT provides polyenergetic images where CT values depend on the tube voltage (kV), hampering quantitative analysis across different CT scans. To mitigate this problem, spectral CT such as photon-counting detector (PCD) CT offers virtual monoenergetic images (VMI) where CT values depend only on the keV level but, ideally, not on the tube voltage. The purpose of this study was to investigate the kV dependence of VMI CT values in PCD-CT across a wide range of tissue types, keV levels, and kV settings for various phantom sizes, and to determine which kV settings yield the optimal contrast-to-noise ratio (CNR) for a given VMI energy and phantom size. The phantom study was complemented with an exploratory patient study.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Materials and methods: &lt;/strong&gt;A spectral abdomen phantom (QSA-543; QRM) with 2 optional fat rings was scanned on a PCD-CT (NAEOTOM Alpha; Siemens Healthineers). The phantom contained rods with 2/5/10/15 mg/mL iodine (QRM); muscle/fat/liver equivalent tissue; and 400 mg/mL calcium (Gammex Sun Nuclear). A standard abdomen protocol was used at tube voltages of 70/90/120/140 kV. Polyenergetic images and VMIs (range: 40 to 100 keV in 5 keV increments) were reconstructed. For each VMI energy (keV), the percentage deviation ΔCT(%) of the mean CT value across the different kV settings was determined for each rod using region-of-interest (ROI) analysis. A ΔCT of 10% was considered the clinically acceptable upper limit. For each kV setting, the iodine CNR was calculated and normalized to the radiation dose (CTDIvol) to obtain CNRD. Higher CNRD indicated higher radiation dose efficiency. Edge spread functions (EFS) and noise power spectra (NPS) were evaluated for various kV settings. In the retrospective patient study, a standard cerebral CT angiography (CTA) protocol was applied at either 140 kV (n = 42) or 90 kV (n = 25), with VMI reconstructed at 55 keV. Both the ΔCT(%) and the CNRD relative to the ventricles were determined for various cerebral arteries. The 2 groups were compared using unpaired t tests.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;For all iodine and calcium rods and all phantom sizes, CT values remained stable within the predefined 10% tolerance across all kV settings in the VMI energy range of 40 to 70 keV, with ΔCT ≤8.4%. At 100 keV, ΔCT increased for low iodine concentration, reaching up to 36%, corresponding to a deviation of 19 HU from the mean CT value of 54 HU for 5 mg/mL iodine. Adipose tissue and liver exhibited ΔCT ≤10% at 45 to 70 keV. At 40 keV, deviations were larger but remained small in absolute terms (11.0 HU for liver and 19.6 HU for adipose tissue in the large phantom). For the small phantom and 40-60 keV, CNRD was 10% to 13% higher for 70/90 kV compared with 120/140 kV. EFS and NPS were consistent across kV settings. This advantage was lost at higher keV and larger phantoms. In patient VMIs at 55 keV, CNRD was 17% to 29% higher at","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":""},"PeriodicalIF":7.9,"publicationDate":"2026-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148968731","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":"The Challenge of Rendering Abnormalities Accurately Using Deep Learning-Based Reconstruction in Accelerated Brain MRI: A Disproportionate Loss of Clinically Relevant Image Information at Higher Rates of Acceleration.","authors":"Shengjia Chen, Patricia M Johnson, Yvonne W Lui","doi":"10.1097/RLI.0000000000001308","DOIUrl":"https://doi.org/10.1097/RLI.0000000000001308","url":null,"abstract":"<p><strong>Objectives: </strong>Deep learning (DL)-based reconstruction methods can substantially accelerate MRI acquisition while preserving image quality relative to traditional techniques. However, concerns remain regarding their ability to accurately reconstruct abnormalities at higher acceleration factors. This study quantitatively assesses the impact of higher-order acceleration on image quality in DL-reconstructed brain MRI in normal and abnormal cases, emphasizing the utmost need to render abnormal findings accurately.</p><p><strong>Materials and methods: </strong>Raw k-space image data from 5847 brain MRI examinations (fastMRI) were used. A radiologist-annotated subset of 1001 examinations (fastMRI+) served as the test set; the remainder were split into training (n=3715) and validation (n=1131) sets. Images were retrospectively undersampled (acceleration factors 2 to 12) and reconstructed using an end-to-end variational network. Image quality metrics, including normalized mean squared error (NMSE), structural similarity index measure (SSIM), and peak signal-to-noise ratio (PSNR), were computed within bounding-box annotations containing abnormalities and in size-matched normal control regions, and at the slice-level. The region-by-acceleration interaction was tested using linear mixed-effects models with a subject-level random intercept.</p><p><strong>Results: </strong>All metrics demonstrated progressive degradation with increasing acceleration across slice-level and bounding-box-level analyses. At lower acceleration rates, bounding boxes with and without abnormalities showed comparable image quality. However, above 4-fold acceleration, NMSE within abnormal regions exhibited a notably sharper increase with rising acceleration compared to normal regions, while abnormal regions demonstrated a significantly faster decline in PSNR and SSIM. This nonsymmetric information loss was particularly evident for NMSE at higher acceleration rates. The region-by-acceleration interaction was statistically significant for all 3 metrics at both levels (all adjusted P<0.001), with the effect largest and most consistent for NMSE.</p><p><strong>Conclusions: </strong>Our findings demonstrate a disproportionate, pathology-localized degradation of reconstruction quality as acceleration increases. This emphasizes the importance of rigorous clinical assessment of image quality in DL-MRI reconstruction, particularly at higher undersampling rates, highlighting the need for reconstruction strategies tailored to maintaining diagnostically critical features.</p>","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":""},"PeriodicalIF":7.9,"publicationDate":"2026-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148963350","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 Distortion Correction for Brain Diffusion-weighted Imaging: A Prospective Comparison With Single-shot and Readout-segmented Echo-planar Imaging.","authors":"Mohammed Khalaf, Sebastian Altmann, Andrea Kronfeld, Roman Paul, Vanessa Ines Schöffling, Marc A Brockmann, Thorsten Feiweier, Shihan Qiu, Ahmed E Othman, Haidara Almansour","doi":"10.1097/RLI.0000000000001311","DOIUrl":"https://doi.org/10.1097/RLI.0000000000001311","url":null,"abstract":"<p><strong>Background: </strong>Single-shot echo-planar imaging DWI (ss-EPI DWI) is susceptible to geometric distortions near air-tissue interfaces, limiting diagnostic accuracy. Multishot readout-segmented DWI (RESOLVE DWI) mitigates these artifacts but requires longer acquisition times. This study evaluated whether ss-EPI DWI with a deep learning-enabled correction of static field inhomogeneities (DL DWI) can achieve effective distortion correction while preserving diagnostic reliability and reducing scan time.</p><p><strong>Objectives: </strong>To compare image quality, geometric distortion, lesion detectability, and diagnostic confidence of ss-EPI DWI with DL-enabled correction of static field inhomogeneities (DL DWI) against conventional ss-EPI DWI (without correction) and RESOLVE DWI.</p><p><strong>Materials and methods: </strong>In this prospective single-center study (April 2025 to August 2025), 100 patients undergoing clinically indicated brain MRI were enrolled following written informed consent. All patients underwent DL ss-EPI DWI with DL correction (1 min 29 s) and RESOLVE DWI (3 min 17 s); ss-EPI DWI was reconstructed by disabling DL correction for all patients. Qualitative and quantitative analyses were performed. Three board-certified radiologists rated image quality, lesion detectability, distortion, and diagnostic confidence on a 5-point Likert Scale. Two quantitative measures of distortion were applied: geometric conformity with anatomic 3D T1-weighted data through coregistration methods and gray-value distributions within volumes of interest in susceptibility-affected regions (temporal lobe, cerebellum, and brainstem).</p><p><strong>Results: </strong>DL DWI significantly outperformed ss-EPI DWI across all qualitative parameters, including diagnostic confidence (median, 4.0 vs. 3.0; P < 0.001), overall image quality (median, 4.0 vs. 3.0; P < 0.001), and geometric distortion (median, 4.0 vs. 3.0; P < 0.001). RESOLVE DWI achieved the highest ratings overall (median, 5.0). Lesion detectability was comparable between DL DWI and RESOLVE DWI (median, 4.0 for both; P > 0.08), while both significantly outperformed ss-EPI DWI (P < 0.001). Quantitative analysis confirmed superior geometric accuracy of DL DWI over ss-EPI DWI, with lower coregistration cost-function values and normalization of gray-value distributions in susceptibility-affected regions.</p><p><strong>Conclusion: </strong>DL DWI improved image quality and geometric accuracy compared with uncorrected ss-EPI DWI. Subjective lesion-detectability ratings were similar between DL DWI and RESOLVE DWI, while DL DWI required less than half the acquisition time. These findings support DL-based distortion correction as a promising, time-efficient approach for brain diffusion-weighted imaging that warrants confirmation in a predefined noninferiority design.</p>","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":""},"PeriodicalIF":7.9,"publicationDate":"2026-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148911856","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":"Accelerated Body Composition Analysis in Whole-body MRI Using CycleGAN-based T2-HASTE Synthesis From Fast Whole-body Localizers.","authors":"Christian Bojahr, Anton Sheahan Quinsten, Judith Kohnke, Yutong Wen, Meijie Li, Sina Warmer, Jannis Straus, Cynthia Sabrina Schmidt, Olivia Barbara Pollok, Mathias Holtkamp, Luca Salhöfer, Max Eberts, Lale Umutlu, Michael Forsting, Johannes Haubold, Felix Nensa, Katarzyna Borys, René Hosch","doi":"10.1097/RLI.0000000000001307","DOIUrl":"https://doi.org/10.1097/RLI.0000000000001307","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Objectives: &lt;/strong&gt;To evaluate whether CycleGAN-based synthesis of T2-HASTE images from routinely acquired fast whole-body localizer (FWBL) can support accelerated body composition analysis (BCA) by preserving sufficient information for an established T2-HASTE-based BCA pipeline to generate measurements comparable to those derived from reference T2-HASTE images.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Materials and methods: &lt;/strong&gt;This retrospective single-center proof-of-concept study included 468 patients (53% female, mean age 51±18 y) who underwent WB-MRI with FWBL and T2-HASTE between March 2012 and December 2025, 431 (92%) of whom were examined from 2023 onward. A CycleGAN model was trained to generate synthetic T2-HASTE images from registered FWBL and T2-HASTE images. Fully automated MRI-based BCA was conducted on synthetic and reference T2-HASTE images using a fixed pretrained BCA model, focusing on 5 key segmentation compartments: subcutaneous adipose tissue (SAT), muscle, abdominal cavity, thoracic cavity, and bone, with subsequent region-specific volumetric analyses of SAT, muscle, and bone in the thoracic, abdominal, and whole-body regions. Derived BCA markers included the Sarcopenia Index (muscle-to-bone ratio) and the muscle-to-SAT ratio. Agreement was assessed using Bland-Altman analysis, including mean bias expressed in absolute units and as a percentage of the mean reference volume, median absolute percentage error, Pearson correlation, and weighted Cohen kappa for tertile-based stratification. Segmentation overlap was evaluated using Sørensen-Dice similarity coefficients. In addition, a qualitative reader evaluation was performed by 4 radiologists across 30 cases.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;Mean percentage bias across the thoracic, abdominal, and whole-body regions was -0.05%, 3.51%, and 2.91% for muscle, -0.19%, -1.21%, and 0.71% for SAT, and -7.10%, -8.86%, and -6.30% for bone, respectively. Median absolute percentage error remained low for muscle (2.96% to 3.52%) and SAT (2.03% to 3.71%), whereas bone showed the highest relative error (5.93% to 8.26%). Tertile-based stratification agreement was high, particularly for the muscle-to-SAT ratio, with unchanged tertile assignment in 89.4% of thoracic, 93.6% of abdominal, and 95.7% of whole-body analyses (κ=0.92, 0.95, and 0.97, respectively). For the Sarcopenia Index, unchanged tertile assignment was 68.1%, 80.9%, and 87.2%, respectively (κ=0.76, 0.86, and 0.90). Segmentation overlap was high across the main compartments, with mean Sørensen-Dice coefficients of 0.90 for SAT, 0.87 for muscle, 0.94 for the abdominal cavity, and 0.91 for the thoracic cavity, whereas bone showed lower overlap (0.76). Qualitative evaluation showed positive ratings for both synthetic image utility and segmentation plausibility, with the synthetic T2 representation rated as providing added value over FWBL for coarse body composition assessment on a 5-point Likert scale, where 1 indicated strong disagreement, an","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":""},"PeriodicalIF":7.9,"publicationDate":"2026-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148900272","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":"Quantitative Multifrequency Ultrasound Imaging Using Narrowband Pulsing for Tissue Characterization.","authors":"Joshua Hanson, Chaodong Wu, Kenneth Hoyt","doi":"10.1097/RLI.0000000000001269","DOIUrl":"10.1097/RLI.0000000000001269","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Objective: &lt;/strong&gt;Multifrequency ultrasound (MFUS) is a novel quantitative imaging technique that captures backscattered data after transmission of a sequence of frequency-shifted narrowband ultrasound (US) pulses. The goal of this study was to implement a MFUS acquisition sequence and then validate quantitative measurements using an animal model of metabolic dysfunction-associated steatotic liver disease (MASLD).&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Materials and methods: &lt;/strong&gt;US imaging was performed using a programmable research scanner (Vantage NXT 256, Verasonics Inc) equipped with a L11-5v linear array. Radiofrequency (RF) data were acquired from 24 different frequency-shifted narrowband transmit pulses using plane wave imaging with spatial angular compounding. The MFUS gradient was defined as the linear slope between logarithmic B-scan intensity and transmit frequency. The US attenuation coefficient and relative scatterer size (RSS) were derived from the MFUS gradient parameter. A bilayer tissue-mimicking phantom with regions of known US attenuation values of -0.70 and -0.95 dB/cm/MHz, respectively, was used for in vitro MFUS imaging and attenuation coefficient estimation. Custom homogeneous phantoms containing 38 to 89 µm-sized US scatterers were also used to compare RSS estimates. A heterogeneous phantom containing a circular target and background material embedded with 64 and 38 µm-sized scatterers, respectively, was used to measure the contrast-to-noise ratio (CNR) between the two regions for B-scan and MFUS-derived RSS estimates. Preclinical US imaging was performed on mice fed standard chow or a methionine and choline-deficient (MCD) diet to induce liver steatosis ( n =5 animals per group). Mice underwent in vivo MFUS imaging, and then attenuation coefficient and RSS estimates were derived for each mouse liver.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;In vitro attenuation estimates were found to be -0.71 ± 0.04 and -0.93 ± 0.03 dB/cm/MHz for a phantom with true attenuation values of -0.70 and -0.95 dB/cm/MHz, respectively. A difference was found in RSS values from homogenous phantoms embedded with different-sized US scatterers and CNR measurements from the heterogeneous inclusion phantom ( P &lt; 0.001). Average CNR values increased from 0.11 to 0.30 when using B-scan and MFUS imaging, respectively. Relative to control animals, in vivo liver imaging studies revealed increased attenuation coefficient and decreased RSS values in mice fed the MCD diet ( P &lt; 0.001). After US imaging, all animals were humanely euthanized and livers excised for histologic analysis.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusion: &lt;/strong&gt;MFUS imaging of phantom materials revealed a sensitivity to changes in attenuation coefficient and US scatterer size conditions. Preliminary preclinical results validated the performance of MFUS-derived parameters for liver tissue characterization. Changes in attenuation coefficient and RSS values were consistent with previous studies. Overall, MFUS is an innova","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":"636-644"},"PeriodicalIF":7.9,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12917945/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145951978","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":"Spectral Black-Blood Photon-Counting CT for High-Resolution Carotid Vessel Wall Imaging: A Feasibility Study.","authors":"Adrienn Tóth, Muhammad Taha Hagar, Moritz C Halfmann, Sardi Hyska, Eric Bass, Pooyan Sahbaee, Markus Jürgens, Milan Vecsey-Nagy, Tilman Emrich, Pal Maurovich-Horvat, Akos Varga-Szemes, Maria Vittoria Spampinato","doi":"10.1097/RLI.0000000000001309","DOIUrl":"https://doi.org/10.1097/RLI.0000000000001309","url":null,"abstract":"<p><strong>Objectives: </strong>To evaluate the feasibility of a novel single-phase spectral black-blood CT (BBCT) technique for high-resolution carotid vessel wall imaging and explore its potential impact on plaque feature visualization.</p><p><strong>Methods: </strong>In this IRB-approved retrospective study, clinically indicated head and neck photon-counting detector (PCD)-CT angiography (CTA) examinations were used to generate high-resolution BBCT reconstructions from a single angiographic-phase data set using spectral iodine suppression. Nine iodine ratio (IR) settings were evaluated to determine the balance between intraluminal suppression and vessel wall preservation. Objective image quality was assessed using attenuation and contrast-to-noise ratio (CNR). Three readers independently assessed overall image quality, lumen visualization, wall-lumen delineation, plaque conspicuity, and high-risk plaque features, including intraplaque hemorrhage (IPH), lipid-rich necrotic core (LRNC), and thin fibrous cap, and compared BBCT with conventional CTA reconstructions (0.4 mm, Qr48 kernel). Inter-reader agreement was assessed using Gwet's agreement coefficient (AC).</p><p><strong>Results: </strong>A total of 40 patients (mean age: 64.1±11.3 y; 57.5% women) were included. Lumen attenuation progressively decreased with lower IR values (range: 51.0 to -176.6 HU), whereas vessel wall attenuation remained relatively preserved (range: 11.4 to 55.8 HU, P=0.004). Lumen-to-wall CNR decreased from 13.6±6.1 to 2.1±1.7, whereas wall-to-fat CNR increased from 7.2±3.8 to 15.3±6.8, with IR 2.0 representing the best balance between lumen suppression and wall conspicuity. Compared with conventional CTA, BBCT improved wall-lumen delineation across readers (median score: 2 to 3 vs. 4; all P<0.001) and plaque conspicuity in evaluable plaques (median score: 3 vs. 4; all P≤0.03), whereas overall image quality was preserved (all P≥0.45). Agreement improved for IPH (AC: 0.63 vs. 0.45), LRNC (0.62 vs. 0.50), and thin fibrous cap assessment (0.70 vs. 0.33). However, the number of cases classified as positive for IPH varied across readers and was lower on BBCT (1 to 9 cases) than on CTA (11 to 14 cases), suggesting possible subtraction-related sensitivity loss.</p><p><strong>Conclusions: </strong>Spectral BBCT was feasible for high-resolution carotid vessel wall imaging, with preserved overall image quality, improved wall-lumen delineation, and higher plaque conspicuity compared with conventional CTA. Improved agreement for selected plaque features supports its potential as a complementary vessel wall reconstruction; however, possible subtraction-related sensitivity loss suggests BBCT should be interpreted in conjunction with conventional CTA rather than as a standalone reconstruction.</p>","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":""},"PeriodicalIF":7.9,"publicationDate":"2026-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148793207","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}