Investigative Radiology最新文献

{"title":"Novel Near Infrared Dyes Targeting Carbonic Anhydrase IX for Fluorescence Imaging Applications.","authors":"Roberta Napolitano, Alessia Adamo, Luca Biondi, Alessia Cordaro, Margherita Iaboni, Francesco Stummo, Francesca La Cava, Francesca Arena, Daniele Faletto, Federica Chianale, Erika Reitano, Luisa Poggi, Francesco Blasi","doi":"10.1097/RLI.0000000000001204","DOIUrl":"https://doi.org/10.1097/RLI.0000000000001204","url":null,"abstract":"<p><strong>Objectives: </strong>Fluorescence tumor-targeted imaging is a sensitive technique that may assist surgeons to remove residual cancer tissue during resection. Carbonic anhydrase IX (CAIX) is a tumor-associated cell-surface glycoprotein, upregulated in hypoxic environments, and a suitable biomarker to develop targeted dyes for fluorescence-guided surgery. This study describes design, synthesis, in vitro and in vivo assessment of novel CAIX-targeting fluorescent probes based on the well-known drug acetazolamide, addressing the contribution of both targeting moiety and fluorophore structure on imaging efficacy.</p><p><strong>Materials and methods: </strong>All the CAIX-targeting heptamethine cyanines synthesized and described in the present work were characterized in terms of their optical properties in different media. The affinity to human serum albumin was evaluated by UV-VIS spectrophotometry. The affinity to the CA catalytic site was determined on a recombinant bovine CAII enzyme (bCAII), with a fluorescent-based assay. Human colon adenocarcinoma HT-29 cells, highly expressing CAIX, were used for the in vitro characterization, including cell binding, uptake and competition assays, by flow cytometry. Finally, the in vivo tumor targeting efficacy of a selected group of probes was assessed by Optical Imaging in a mouse subcutaneous tumor from HT-29 cells, characterized by both expression of CAIX and a hypoxic tumor microenvironment.</p><p><strong>Results: </strong>First, a family of CAIX-targeting probes was prepared by functionalizing a novel glucamine-bearing heptamethine cyanine (Dye1) with a modified acetazolamide moiety, whose acetyl group was replaced with i) aminooctanoic acid C8, ii) phenylalanine, iii) amino-PEG2-acid and iv) the longer linker 4a, or 2 commercially available benzenesulfonamides. From the in vitro screening of this first group of compounds, the C8-AZA targeting moiety was selected due to its highest affinity. Indeed, Dye1-C8-AZA exhibited the lowest KD values for both bCAII (6.1 ± 1.6 nM) and CAIX-expressing HT-29 cells (58 ± 9 nM), even lower than HypoxyFluor-1 (HF-1), a CAIX-targeted dye already reported in the literature. Then, other heptamethine cyanines (Dye2-Dye5, linear or cyclic, with different substituents on the indolenines and different conjugation position of the targeting vector) were functionalized with C8-AZA and fully characterized both in vitro and in vivo, to evaluate the combinatory effect of vector and fluorophore on the performance of the resulting probes. The different chemical features of the cyanines influenced the optical properties, solubility, binding with albumin, biodistribution, and imaging efficacy of the probes, while leaving unaffected the high affinity to the target. When tested in vivo for the visualization of CAIX-expressing HT-29 tumors, all C8-AZA probes showed high and specific tumor accumulation, often superior to HF-1.</p><p><strong>Conclusions: </strong>Several CAIX-targe","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":""},"PeriodicalIF":7.0,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143990668","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":"Contrast Agent-Specific Parameter Optimization for T1-Weighted Fast Spoiled Gradient Echo Imaging: Use Cases for Gadoterate Meglumine and Gadobutrol at 1.5T and 3.0T.","authors":"Dimosthenis E Gkotsis, Anand Bherwani, Eftychia Z Kapsalaki, Courtney J Bishop, Adam J Schwarz","doi":"10.1097/RLI.0000000000001205","DOIUrl":"https://doi.org/10.1097/RLI.0000000000001205","url":null,"abstract":"<p><strong>Objectives: </strong>The objective of this study is to derive a contrast agent-specific theoretical framework to optimize acquisition parameters for contrast-enhanced magnetic resonance imaging (MRI) based on the physiochemical properties of gadolinium-based contrast agents, focusing on fast spoiled gradient recalled echo sequences. The goal is to enhance the lesion-to-background contrast for improved diagnostic sensitivity in clinical applications.</p><p><strong>Materials and methods: </strong>Signal equations for fast spoiled gradient recalled echo sequences were derived for nonenhancing and enhancing tissues using gadoterate meglumine and gadobutrol, characterized by distinct longitudinal (r1) and transverse (r2/r*2) relaxivities. Simulations were conducted at 2 field strengths, 1.5T and 3.0T, and various scenarios were considered, including hypothetical lesions with T1 ratios ranging from 1.1 to 1.8. The signal behavior was analyzed across a range of initial conditions, including different spin densities and field-strength dependent variations in tissue relaxation times. The optimal flip angle and repetition time combinations were determined to maximize contrast. In vivo validation was performed on 2 patients undergoing contrast-enhanced MRI of the brain, using the proposed acquisition parameters.</p><p><strong>Results: </strong>The modeling and simulations revealed that the flip angle that maximizes signal intensity for a contrast-enhancing lesion (Ernst angle) differs from the flip angle that maximizes T1-dependent contrast between lesion and healthy tissue in unenhanced MRI (Pelc angle) and also differs from the flip angle that maximizes the same in contrast-enhanced MRI. The theoretical simulations indicated possible contrast gains of 24%-28% using optimized parameters. The in vivo acquisitions demonstrated contrast gains of 19%-44% for a diffuse enhancing lesion and 91% for a weakly enhancing focal lesion, when comparing the optimized acquisition parameters to manufacturer's default settings.</p><p><strong>Conclusions: </strong>Adjusted repetition time and flip angle values, derived using the proposed framework, improved the image contrast between healthy and diseased tissues, enhancing the visualization of abnormalities. This approach can be used to optimize routine clinical MRI protocols and balance scan time with contrast enhancement. This may translate to more precise lesion detection, potentially leading to earlier and more accurate diagnosis or treatment monitoring in clinical practice.</p>","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":""},"PeriodicalIF":7.0,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144009759","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":"Multimodal Imaging Demonstrates Antifibrotic Effects of Targeting αvβ6/αvβ1 Integrins in Biliary Fibrosis.","authors":"Yingying Ning, Iris Y Zhou, Johanna R Schaub, Nicholas J Rotile, Avery Boice, Ilknur Ay, Scott Turner, Peter Caravan","doi":"10.1097/RLI.0000000000001202","DOIUrl":"https://doi.org/10.1097/RLI.0000000000001202","url":null,"abstract":"<p><strong>Objectives: </strong>Development of molecular therapies for liver fibrosis is slowed by a lack of noninvasive methods addressing questions of target expression, target engagement, and treatment response. Integrin αvβ6 is a biomarker of liver fibrosis that is upregulated in livers of patients with primary sclerosing cholangitis. It activates latent TGF-β and plays a critical role in regulating extracellular matrix expression, especially collagen. In this study, our aim was to use combined αvβ6 integrin-targeted positron emission tomography (PET) and collagen-specific magnetic resonance imaging (MRI) to measure target expression/engagement and liver fibrosis reduction with a αvβ6 integrin inhibitor.</p><p><strong>Materials and methods: </strong>We conducted a treatment study in bile duct-ligated (BDL) rats using a small molecule inhibitor to αvβ6/αvβ1. 68Ga-DOTA-R01-MG, an αvβ6-specific PET probe, was used to noninvasively measure αvβ6 expression and target engagement in the liver. CM-101, a type I collagen MRI probe, was used to quantify fibrosis.</p><p><strong>Results: </strong>68Ga-DOTA-R01-MG PET showed 3-fold higher liver uptake in BDL rats compared with sham rats at 17 days after surgery. Pretreatment with high dose αvβ6/αvβ1 inhibitor 1 hour before imaging significantly decreased liver PET uptake in BDL rats (31%, P = 0.012). Two weeks of daily dosing with an αvβ6/αvβ1 inhibitor attenuated αvβ6 expression in BDL rat liver as assessed by αvβ6 PET (0.27 ± 0.07 percent injected dose [%ID]/mL compared with 0.40 ± 0.09 %ID/mL in vehicle-treated group, P = 0.014) and reduced liver fibrosis as assessed by collagen MRI (liver relaxation rate change ΔR1 = 0.14 ± 0.11 vs 0.36 ± 0.06, P = 0.0037). Imaging findings were confirmed by histology (collagen proportionate area 10.7 ± 2.8% vs 22.5 ± 6.1%, P < 0.001).</p><p><strong>Conclusions: </strong>A single imaging protocol combining molecular MRI and PET can be used to effectively monitor integrin inhibitor treatment by measuring target expression/engagement and treatment outcomes. Multimodality molecular imaging may be valuable in accelerating drug development in molecular therapies for liver fibrosis.</p>","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":""},"PeriodicalIF":7.0,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143964942","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 Phase Information of 3D Isotropic Ultrashort Echo Time Pulmonary MRI for the Detection of Thoracic Lymphadenopathy: Toward an All-in-One Scan Solution.","authors":"Sebastian Ziegelmayer, Anh Tu Van, Kilian Weiss, Alexander W Marka, Tristan Lemke, Florian Scheuerer, Thomas Huber, Andreas Sauter, Ryan Robison, Joshua Gawlitza, Marcus R Makowski, Dimitrios C Karampinos, Markus Graf","doi":"10.1097/RLI.0000000000001135","DOIUrl":"10.1097/RLI.0000000000001135","url":null,"abstract":"<p><strong>Background: </strong>Ultrashort echo time (UTE) allows imaging of tissues with short relaxation times, but it comes with the expense of long scan times. Magnitude images of UTE magnetic resonance imaging (MRI) are widely used in pulmonary imaging due to excellent parenchymal signal, but have insufficient contrast for other anatomical regions of the thorax. Our work investigates the value of UTE phase images (UTE-Ps)-generated simultaneously from the acquired UTE signal used for the magnitude images-for the detection of thoracic lymph nodes based on water-fat contrast. It employs an advanced imaging sequence and reconstruction allowing isotropic 3D UTE MRI in clinically acceptable scan times.</p><p><strong>Methods: </strong>In our prospective study, 42 patients with 136 lymph nodes had undergone venous computed tomography and pulmonary MRI scans with UTE within a 14-day interval. 3D isotropic UTE images were acquired using FLORET (fermat looped, orthogonally encoded trajectories). Background-corrected phase images (UTE-P) and magnitude images were reconstructed simultaneously from the UTE-Signal. Three radiologists performed a blinded reading in which all lymph nodes with a short-axis diameter (SAD) of at least 0.5 cm were detected. Detection rates and performance metrics of UTE-P for all lymph node regions and for pathologic (SAD ≥10 mm) and nonpathologic lymph nodes (SAD <10 mm) were calculated using computed tomography as a reference. The interreader agreement defined as the presence or absence of lymph nodes based on patient and region was calculated using Fleiss kappa (κ).</p><p><strong>Findings: </strong>In the phase images, pathologic lymph nodes in the mediastinal and hilar region were detected with a high diagnostic confidence due to the achieved water-fat contrast (average sensitivity, specificity, positive predictive value, and negative predictive value of 95.83% [confidence interval (CI), 92.76%-98.91%], 100%, 100%, and 99.32% [CI, 98.08%-100%]). Stepwise inclusion of all lymph node regions and nonpathologic lymph nodes was associated with a moderate decrease resulting in an average sensitivity, specificity, positive predictive value, and negative predictive value of 77.9% (CI, 70.9%-84.7%), 99.4% (CI, 98.7%-99.9%), 97.0% (CI, 93.4%-99.7%), and 94.7% (CI, 92.8%-96.4%) for the inclusion of all lymph nodes sizes and regions. Interreader agreement was almost perfect (κ = 0.92).</p><p><strong>Conclusions: </strong>Pathological lymph nodes in the mediastinal and hilar region can be detected in phase-images with high diagnostic confidence, thanks to the ability of the phase images to depict water-fat contrast in combination with high spatial 3D resolution, extending the clinical applicability of UTE into the simultaneous assessment of lung parenchyma and lymph nodes.</p>","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":"334-339"},"PeriodicalIF":7.0,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142836663","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":"Metastasis Detection Using True and Artificial T1-Weighted Postcontrast Images in Brain MRI.","authors":"Robert Haase, Thomas Pinetz, Erich Kobler, Zeynep Bendella, Daniel Paech, Ralf Clauberg, Martha Foltyn-Dumitru, Verena Wagner, Kai Schlamp, Gudula Heussel, Claus Peter Heussel, Martin Vahlensieck, Julian A Luetkens, Heinz-Peter Schlemmer, Louisa Specht-Riemenschneider, Alexander Radbruch, Alexander Effland, Katerina Deike","doi":"10.1097/RLI.0000000000001137","DOIUrl":"10.1097/RLI.0000000000001137","url":null,"abstract":"<p><strong>Objectives: </strong>Small lesions are the limiting factor for reducing gadolinium-based contrast agents in brain magnetic resonance imaging (MRI). The purpose of this study was to compare the sensitivity and precision in metastasis detection on true contrast-enhanced T1-weighted (T1w) images and artificial images synthesized by a deep learning method using low-dose images.</p><p><strong>Materials and methods: </strong>In this prospective, multicenter study (5 centers, 12 scanners), 917 participants underwent brain MRI between October 2021 and March 2023 including T1w low-dose (0.033 mmol/kg) and full-dose (0.1 mmol/kg) images. Forty participants with metastases or unremarkable brain findings were evaluated in a reading (mean age ± SD, 54.3 ± 15.1 years; 24 men). True and artificial T1w images were assessed for metastases in random order with 4 weeks between readings by 2 neuroradiologists. A reference reader reviewed all data to confirm metastases. Performances were compared using mid- P McNemar tests for sensitivity and Wilcoxon signed rank tests for false-positive findings.</p><p><strong>Results: </strong>The reference reader identified 97 metastases. The sensitivity of reader 1 did not differ significantly between sequences (sensitivity [precision]: true, 66.0% [98.5%]; artificial, 61.9% [98.4%]; P = 0.38). With a lower precision than reader 1, reader 2 found significantly more metastases using true images (sensitivity [precision]: true, 78.4% [87.4%]; artificial, 60.8% [80.8%]; P < 0.001). There was no significant difference in sensitivity for metastases ≥5 mm. The number of false-positive findings did not differ significantly between sequences.</p><p><strong>Conclusions: </strong>One reader showed a significantly higher overall sensitivity using true images. The similar detection performance for metastases ≥5 mm is promising for applying low-dose imaging in less challenging diagnostic tasks than metastasis detection.</p>","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":"340-348"},"PeriodicalIF":7.0,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142836665","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 and In Vivo Human Performance of Brand Name Versus Generic Ferumoxytol.","authors":"Rianne A van der Heijden, Daiki Tamada, Lu Mao, James Rice, Scott B Reeder","doi":"10.1097/RLI.0000000000001130","DOIUrl":"10.1097/RLI.0000000000001130","url":null,"abstract":"<p><strong>Objectives: </strong>Ferumoxytol is a superparamagnetic iron-oxide product that is increasingly used off-label for contrast-enhanced magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA). With the recent regulatory approval of generic ferumoxytol, there may be an opportunity to reduce cost, so long as generic ferumoxytol has similar imaging performance to brand name ferumoxytol. This study aims to compare the relaxation-concentration dependence and MRI performance of brand name ferumoxytol with generic ferumoxytol through phantom and in vivo experiments. The secondary purpose was to determine the optimal flip angle and optimal weight-based dosing.</p><p><strong>Materials and methods: </strong>Phantom experiments were performed using both brand name (AMAG Pharmaceuticals) and generic (Sandoz Pharmaceuticals) ferumoxytol products. Each ferumoxytol product was diluted in saline, and separately in adult bovine whole blood, at 5 iron concentrations ranging from 0.3 to 2.1 mM. Vials were placed in an MR-compatible water bath at 37°C and imaged at both 1.5 T and 3.0 T. Longitudinal and transverse relaxation rate constants (R1, R2, R2*) were measured for each ferumoxytol concentration, and relaxation-concentration curves were estimated. An in vivo dose accumulation study with flip angle optimization was also implemented using a cross-over design, in healthy volunteers. Cumulative doses of 1, 3, 5, and 7 mg/kg diluted ferumoxytol were administered prior to MRA of the chest on a 3.0 T clinical MRI system. For each incremental dose, the flip angle was varied from 40° to 10° in -10° increments over 5 breath-holds followed by a repeated 40° flip angle acquisition. Regions of interest were drawn in the aortic arch, paraspinous muscles, and a noisy area outside of the patient, free from obvious artifact. Signal-to-noise ratio (SNR) was calculated as the quotient of the average signal in the aortic arch and the standard deviation of the noise, corrected for a Rician noise distribution. Contrast-to-noise ratio was calculated as the difference in SNR between the aorta and paraspinous muscles. Absolute SNR and contrast-to-noise ratio values were compared between products for different flip angles and doses.</p><p><strong>Results: </strong>There were no statistically significant or clinically relevant differences in relaxation-concentration curves between AMAG and Sandoz products in phantom experiments. Six healthy volunteers (38.8 ± 11.5 years, 3 female, 3 male) were successfully recruited and completed both imaging visits. No clinically relevant differences in image quality were observed between ferumoxytol products. The optimal flip angle range and dose for both products was 20°-30° and 5 mg/kg, respectively.</p><p><strong>Conclusions: </strong>Brand name and generic ferumoxytol products can be used interchangeably for MRA.</p>","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":"319-327"},"PeriodicalIF":7.0,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142500558","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":"Photon-Counting CT Iodine Maps for Diagnosing Chronic Pulmonary Thromboembolism: A Pilot Study.","authors":"Bjarne Kerber, Thomas Flohr, Silvia Ulrich, Mona Lichtblau, Thomas Frauenfelder, Sabine Franckenberg","doi":"10.1097/RLI.0000000000001134","DOIUrl":"10.1097/RLI.0000000000001134","url":null,"abstract":"<p><strong>Objectives: </strong>The aim of this study was to evaluate the feasibility and efficacy of chronic pulmonary thromboembolism assessment using photon-counting detector computed tomography (PCD-CT) iodine maps of the lung parenchyma.</p><p><strong>Materials and methods: </strong>This institutional review board-approved retrospective study included 83 subjects (49.4% male, aged 62.4 ± 13.4 years; 50.6% female, aged 59.9 ± 17.1 years) who underwent clinically indicated PCD-CT scan to rule out chronic thromboembolic pulmonary hypertension (CTEPH). Two blinded readers used iodine maps and corresponding sharp-kernel CT reconstructions in the lung window to evaluate perfusion defects and identify patients with chronic pulmonary thromboembolism (CTEPH, CTEPH overlap with other causes of pulmonary hypertension [PH], chronic thromboembolic disease [CTED]). No other clinical or imaging information was given. Discordance was resolved in a subsequent consensus read. The clinical diagnosis was reviewed in an interdisciplinary clinical setting. The accuracy, sensitivity, and specificity of radiologic evaluation and clinical diagnosis were calculated.</p><p><strong>Results: </strong>Of the 83 subjects included, 32 were diagnosed with CTEPH, CTEPH overlap, or CTED, 35 were diagnosed with PH caused by other pathologic mechanisms, 10 had no PH, and 6 had suffered previous acute pulmonary embolism, which resolved. The interreader agreement was good (Cohen κ = 0.74). The consensus reached high accuracy (0.88), sensitivity (0.94), and specificity (0.84), as well as good agreement with interdisciplinary clinical diagnosis (Cohen κ = 0.75). No cases with confirmed CTEPH as the primary cause of PH or CTED were missed. Patients with pulmonary arterial hypertension were most frequently rated false-positive. The mean effective dose (±standard deviation) was 1.3 (±0.76) mSv.</p><p><strong>Conclusions: </strong>Accurate, sensitive, and specific diagnosis of pulmonary chronic thromboembolism at low radiation dose is possible using iodine maps reconstructed from PCD-CT scans.</p>","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":"328-333"},"PeriodicalIF":7.0,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142604398","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":"Impact of a Prototype 29:1 Ratio Grid on Image Quality and Radiation Dose in Abdominal Angiography: Evaluation in a Pig Model.","authors":"Thomas Werncke, Lena S Becker, Sabine K Maschke, Inga Brüsch, Regina Rumpel, Frank K Wacker, Bernhard C Meyer","doi":"10.1097/RLI.0000000000001136","DOIUrl":"10.1097/RLI.0000000000001136","url":null,"abstract":"<p><strong>Objectives: </strong>The aim of this study was to evaluate the impact of a prototype grid with a 29:1 ratio (r29) and a 15:1 (r15) grid on the image quality (IQ) and radiation dose in abdominal angiography.</p><p><strong>Materials and methods: </strong>Six typical abdominal angiographic image scenarios were created in 4 pigs. Polymethylmethacrylate and aluminum plates were used to add 10 cm of patient equivalent thickness to simulate different body types. Fluoroscopic images were acquired with a source-to-image receptor distance of 120 cm. Tantalum- and iron-specific acquisition protocols at different IQ levels were acquired. IQ of radiation dose equivalent image pairs, created with the r29 and r15 grids, respectively, was quantitatively evaluated using contrast-to-noise ratio (CNR) measurements. Differences in radiation dose were estimated using the dose-weighted CNR. Two blinded readers compared IQ of these images using a Likert scale. In a second step, the readers selected pairs of the r29 and r15 images with subjectively equivalent IQ. Radiation doses were then compared.</p><p><strong>Results: </strong>Compared with the r15 grid, the r29 grid images achieved similar CNR at an average of 26% (±12%) lower radiation dose at a mean patient equivalent thickness of 26 cm and 36 cm. Both readers noted a significant increase in IQ ( P < 0.001) for dose equivalent images, whereas the interobserver agreement was 0.59. For the selected IQ equivalent images, a radiation dose reduction of 38% (±17%; P < 0.001, interobserver agreement 0.92) was noted when using the r29 grid.</p><p><strong>Conclusions: </strong>The use of an r29 grid at a large source-to-image receptor distance can significantly improve the IQ compared with the r15 grid at the same radiation dose in abdominal angiography or can reduce radiation dose while preserving IQ.</p>","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":"349-355"},"PeriodicalIF":7.0,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142768859","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":"Low-Field MRI for Dental Imaging in Pediatric Patients With Supernumerary and Ectopic Teeth: A Comparative Study of 0.55 T and Ultra-Low-Dose CT.","authors":"Ines Willershausen, Stefania Evangeliou, Hans-Peter Fautz, Patrick Amarteifio, Matthias Stefan May, Armin Stroebel, Martin Zeilinger, Michael Uder, Lina Goelz, Markus Kopp","doi":"10.1097/RLI.0000000000001129","DOIUrl":"10.1097/RLI.0000000000001129","url":null,"abstract":"<p><strong>Objectives: </strong>This study sought to elucidate the diagnostic performance of 0.55 T magnetic resonance imaging (MRI) for pediatric dental imaging, specifically in terms of the image quality (IQ) for detecting ectopic and/or supernumerary teeth, compared with routine ultra-low-dose computed tomography (ULD-CT) of the jaw.</p><p><strong>Materials and methods: </strong>A total of 16 pediatric patients (mean age: 12.4 ± 2.6 years, range: 9-17 years) with ectopic and/or supernumerary teeth screened from January 2023 to January 2024 were enrolled in this prospective, single-center study. All patients underwent ULD-CT as the clinical reference standard and 0.55 T MRI as the study scan on the same day. A 0.6-mm isotropic 3-dimensional T1w FLASH sequence was developed with a dedicated field of view of the upper and lower jaws. ULD-CT was performed using a new single-source computed tomography (CT) scanner equipped with a tin filter (Sn100, slice thickness: 1 mm, quality reference mAs: 24). The IQ for the tooth axis, the tooth length, the tooth root, root resorptions, cysts, the periodontal ligament space, and the mandibular canal was evaluated twice by 3 senior readers using a 5-point Likert scale (LS) (LS score of 1: insufficient, 3: reduced IQ but sufficient for clinical use, and 5: perfect) and compared between both methods. Subsequently, the results were dichotomized into nonvalid (LS score of ≤2) and valid (LS score of ≥3) for clinical use.</p><p><strong>Results: </strong>A total of 49 ectopic and/or supernumerary teeth in 16 pediatric patients were investigated using ULD-CT (CTDI: 0.43 ± 0.09 mGy) and 0.55 T MRI. The mean MRI acquisition time was 9:45 minutes. Motion artifacts were nonsignificantly different between 0.55 T MRI and ULD-CT ( P = 0.126). The IQ for the tooth axis, the tooth root, root resorptions, and cysts was similar between the methods. The IQ for the periodontal ligament space and tooth length favored ULD-CT by 14% (confidence interval [CI]: 4.3%-24%) and 7.5% (CI: 1.8%-13%), respectively, whereas that for the mandibular canal favored 0.55 T MRI by -35% (CI: -54%-16%). Sufficient IQ was found especially for cystic lesions (CT: 100% sufficient, MRI: 95% sufficient), the tooth root (CT: 100%, MRI: 98%), root resorptions (CT: 94%; MRI: 85%), the tooth axis (CT: 100%; MRI: 98%), and the tooth length (CT: 99%; MRI: 91%).</p><p><strong>Conclusions: </strong>The findings indicate that 0.55 T MRI is a feasible, radiation-free technique for delineating ectopic and/or supernumerary teeth in pediatric patients. Nevertheless, to date, 0.55 T MRI has not yet been able to provide an optimal IQ for all anatomical tooth and jaw structures. In cases of advanced clinical indications that require optimal spatial resolution, high-resolution CT or cone-beam CT may still be necessary.</p>","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":"299-310"},"PeriodicalIF":7.0,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142500557","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":"Significance of Image Reconstruction Parameters for Future Lung Cancer Risk Prediction Using Low-Dose Chest Computed Tomography and the Open-Access Sybil Algorithm.","authors":"Judit Simon, Peter Mikhael, Alexander Graur, Allison E B Chang, Steven J Skates, Raymond U Osarogiagbon, Lecia V Sequist, Florian J Fintelmann","doi":"10.1097/RLI.0000000000001131","DOIUrl":"10.1097/RLI.0000000000001131","url":null,"abstract":"<p><strong>Purpose: </strong>Sybil is a validated publicly available deep learning-based algorithm that can accurately predict lung cancer risk from a single low-dose computed tomography (LDCT) scan. We aimed to study the effect of image reconstruction parameters and CT scanner manufacturer on Sybil's performance.</p><p><strong>Materials and methods: </strong>Using LDCTs of a subset of the National Lung Screening Trial participants, which we previously used for internal validation of the Sybil algorithm (test set), we ran the Sybil algorithm on LDCT series pairs matched on kilovoltage peak, milliampere-seconds, reconstruction interval, reconstruction diameter, and either reconstruction filter or axial slice thickness. We also evaluated the cumulative effect of these parameters by combining the best- and the worst-performing parameters. A subanalysis compared Sybil's performance by CT manufacturer. We considered any LDCT positive if future lung cancer was subsequently confirmed by biopsy or surgical resection. The areas under the curve (AUCs) for each series pair were compared using DeLong's test.</p><p><strong>Results: </strong>There was no difference in Sybil's performance between 1049 pairs of standard versus bone reconstruction filter (AUC at 1 year 0.84 [95% confidence interval (CI): 0.70-0.99] vs 0.86 [95% CI: 0.75-0.98], P = 0.87) and 1961 pairs of standard versus lung reconstruction filter (AUC at 1 year 0.98 [95% CI: 0.97-0.99] vs 0.98 [95% CI: 0.96-0.99], P = 0.81). Similarly, there was no difference in 1288 pairs comparing 2-mm versus 5-mm axial slice thickness (AUC at 1 year 0.98 [95% CI: 0.94-1.00] vs 0.99 [95% CI: 0.97-0.99], P = 0.68). The best-case scenario combining a lung reconstruction filter with 2-mm slice thickness compared with the worst-case scenario combining a bone reconstruction filter with 2.5-mm slice thickness uncovered a significantly different performance at years 2-4 ( P = 0.03). Subanalysis showed no significant difference in performance between Siemens and Toshiba scanners.</p><p><strong>Conclusions: </strong>Sybil's predictive performance for future lung cancer risk is robust across different reconstruction filters and axial slice thicknesses, demonstrating its versatility in various imaging settings. Combining favorable reconstruction parameters can significantly enhance predictive ability at years 2-4. The absence of significant differences between Siemens and Toshiba scanners further supports Sybil's versatility.</p>","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":"311-318"},"PeriodicalIF":7.0,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142500559","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}