Investigative Radiology最新文献

{"title":"Free-Breathing Hybrid Technique for Simultaneous Morphological and Quantitative Abdominal Imaging at 0.55 T.","authors":"Mahesh B Keerthivasan, Mary Bruno, Eddy Solomon, Ryan Brown, Douglas Brantner, Kai Tobias Block, Hersh Chandarana","doi":"10.1097/RLI.0000000000001214","DOIUrl":"10.1097/RLI.0000000000001214","url":null,"abstract":"<p><strong>Objectives: </strong>Quantitative proton density fat fraction (PDFF) and R2* estimation at lower field strengths, such as 0.55 T, is challenging due to lower signal-to-noise ratio, reduced fat water chemical shift, and increased T2* relaxation times. In this study, we propose a 3D hybrid technique for abdominal imaging at 0.55 T that enables the simultaneous acquisition of T2-weighted and T1-weighted images and quantification of fat fraction and R2* parameters.</p><p><strong>Materials and methods: </strong>Numerical simulations were performed to optimize a prototype radial hybrid turbo spin echo gradient echo (TSE-GRE) acquisition scheme for improved PDFF and R2* estimation accuracy. Phantom imaging experiments with and without motion were performed to evaluate the sensitivity of the estimation to external motion. Eleven volunteers were imaged on a prototype 0.55 T system. Data were acquired using the proposed technique under free-breathing conditions, and motion-compensated reconstruction was performed using the respiratory signal from a pilot-tone device. Image contrast and estimation performance were compared with conventional acquisition schemes in vitro and in vivo.</p><p><strong>Results: </strong>Numerical simulations indicated R2* estimation accuracy was more sensitive to the choice of echo time compared with PDFF. Performing motion compensation reduced the mean error in R2* from 24 to 5 s -1 while the mean error in PDFF only reduced from 2.7% to 1.6%. The proposed technique generated T2-weighted images with comparable relative liver-spleen contrast as conventional imaging and there were no significant differences ( P >0.05) in the PDFF and R2* values estimated from the hybrid technique compared with conventional multi-echo GRE. Further, the free-breathing acquisition allowed improved slice coverage while overcoming breath-hold limitations of conventional acquisition schemes.</p><p><strong>Conclusions: </strong>The use of a hybrid TSE-GRE acquisition technique can allow simultaneous morphological and quantitative PDFF and R2* estimation at 0.55 T under free-breathing conditions.</p>","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":"111-120"},"PeriodicalIF":7.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13051262/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144284371","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":"Leveraging Representation Learning for Bi-parametric Prostate MRI to Disambiguate PI-RADS 3 and Improve Biopsy Decision Strategies.","authors":"Lavanya Umapathy, Patricia M Johnson, Tarun Dutt, Angela Tong, Sumit Chopra, Daniel K Sodickson, Hersh Chandarana","doi":"10.1097/RLI.0000000000001218","DOIUrl":"10.1097/RLI.0000000000001218","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Objectives: &lt;/strong&gt;Despite its high negative predictive value (NPV) for clinically significant prostate cancer (csPCa), MRI suffers from a substantial number of false positives, especially for intermediate-risk cases. In this work, we determine whether a deep learning model trained with PI-RADS-guided representation learning can disambiguate the PI-RADS 3 classification, detect csPCa from bi-parametric prostate MR images, and avoid unnecessary benign biopsies.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Materials and methods: &lt;/strong&gt;This study included 28,263 MR examinations and radiology reports from 21,938 men imaged for known or suspected prostate cancer between 2015 and 2023 at our institution (21 imaging locations with 34 readers), with 6352 subsequent biopsies. We trained a deep learning model, a representation learner (RL), to learn how radiologists interpret conventionally acquired T2-weighted and diffusion-weighted MR images, using exams in which the radiologists are confident in their risk assessments (PI-RADS 1 and 2 for the absence of csPCa vs. PI-RADS 4 and 5 for the presence of csPCa, n=21,465). We then trained biopsy-decision models to detect csPCa (Gleason score ≥7) using these learned image representations, and compared them to the performance of radiologists, and of models trained on other clinical variables (age, prostate volume, PSA, and PSA density) for treatment-naïve test cohorts consisting of only PI-RADS 3 (n=253, csPCa=103) and all PI-RADS (n=531, csPCa=300) cases.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;On the 2 test cohorts (PI-RADS-3-only, all-PI-RADS), RL-based biopsy-decision models consistently yielded higher AUCs in detecting csPCa (AUC=0.73 [0.66, 0.79], 0.88 [0.85, 0.91]) compared with radiologists (equivocal, AUC=0.79 [0.75, 0.83]) and the clinical model (AUCs=0.69 [0.62, 0.75], 0.78 [0.74, 0.82]). In the PIRADS-3-only cohort, all of whom would be biopsied using our institution's standard of care, the RL decision model avoided 41% (62/150) of benign biopsies compared with the clinical model (26%, P &lt;0.001), and improved biopsy yield by 10% compared with the PI-RADS ≥3 decision strategy (0.50 vs. 0.40). Furthermore, on the all-PI-RADS cohort, RL decision model avoided 27% of additional benign biopsies (138/231) compared to radiologists (33%, P &lt;0.001) with comparable sensitivity (93% vs. 92%), higher NPV (0.87 vs. 0.77), and biopsy yield (0.75 vs. 0.64). The combination of clinical and RL decision models further avoided benign biopsies (46% in PI-RADS-3-only and 62% in all-PI-RADS) while improving NPV (0.82, 0.88) and biopsy yields (0.52, 0.76) across the 2 test cohorts.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusions: &lt;/strong&gt;Our PI-RADS-guided deep learning RL model learns summary representations from bi-parametric prostate MR images that can provide additional information to disambiguate intermediate-risk PI-RADS 3 assessments. The resulting RL-based biopsy decision models also outperformed radiologists in avoiding benign biopsies while maintaining com","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":"127-135"},"PeriodicalIF":8.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12336996/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144527976","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":"Abnormal Pancreaticobiliary Junction in Children: Frequency on Magnetic Resonance Cholangiopancreatography and Associated Pancreaticobiliary Diseases.","authors":"Khuld A Saeedi, Govind B Chavhan, Tanja Gonska, Vicky L Ng, Blayne A Sayed, Caroline Rutten","doi":"10.1097/RLI.0000000000001217","DOIUrl":"10.1097/RLI.0000000000001217","url":null,"abstract":"<p><strong>Background and aims: </strong>There is scarcity of data on the prevalence of abnormal pancreaticobiliary junction (APBJ) in children. This study aimed to determine the frequency and clinical significance of APBJ including pancreas divisum (PD) and common channel (CC) using magnetic resonance cholangiopancreatography (MRCP).</p><p><strong>Materials and methods: </strong>Single-center, retrospective study of MRCPs in children aged 0 to 18 years from 2012 to 2022. Two independent readers assessed PBJ visibility, abnormalities (PD, CC, other), and CC length. Findings were correlated with presenting diagnoses of choledochal cyst, biliary lithiasis, and pancreatitis.</p><p><strong>Results: </strong>A total of 631 MRCPs were included (46.8% females; mean age: 12 ± 5 y). The PBJ was visible in 85.7% of cases. APBJ was observed in 114/631 (18.1%) children, with PD in 47 (7.4%) cases and CC in 61 (9.7%) cases, with an average length of 9 mm (range, 3 to 22 mm). There was a significant inverse association between PD and biliary lithiasis ( P = 0.02). There was no association between PD and pancreatitis. CC was significantly associated with choledochal cyst ( P < 0.0001), pancreatitis ( P = 0.004) and biliary lithiasis ( P < 0.0001), with 21/61 (34.4%) of CC demonstrating stones within (median age: 3.8 y). The CC length was also significantly associated with complications ( P = 0.014), with complication-free cases having a median length of 7 mm (range, 4 to 8) compared with 11 mm (range, 3 to 25) in complicated cases.</p><p><strong>Conclusion: </strong>APBJ is a frequent finding on pediatric MRCP. CC is significantly associated with choledochal cyst, pancreatitis and lithiasis, and may show stones within them, particularly in small children. PD is inversely associated with biliary lithiasis. Careful PBJ assessment is important in children.</p>","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":"121-126"},"PeriodicalIF":8.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144302063","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":"Tolerability and Long-Term Safety of Gadolinium-Based Contrast-Enhanced Interstitial Pedal MR Lymphangiography in Patients With Lymphedema.","authors":"Andreas Henkel, Sergej Geiger, Julia Wagenpfeil, Daniel L Kuetting, Julian A Luetkens, Claus C Pieper","doi":"10.1097/RLI.0000000000001213","DOIUrl":"10.1097/RLI.0000000000001213","url":null,"abstract":"<p><strong>Objectives: </strong>Contrast-enhanced MR lymphangiography (CE-MRL) with pedal interstitial injection of a gadolinium-based contrast agent is increasingly employed in patients with lymphedema (off-label use). However, data on short-term tolerability and possible long-term adverse effects are limited. This study aimed to report clinical experiences regarding the tolerability and long-term safety of CE-MRL.</p><p><strong>Materials and methods: </strong>A total of 168 patients (36 male; mean age 49.1±16.4 y) with clinically diagnosed lymphedema underwent clinically indicated CE-MRL. A total of 8 mL of diluted MR contrast agent (6 mL 1.0 mmol/mL Gadobutrol, 2 mL saline solution) was prepared. After intradermal administration of 0.2 mL local anesthetic, 1 mL of this contrast agent solution was injected intradermally into each interdigital space. To assess tolerability, patients were asked after the examination about their experience regarding remaining motionless during the examination, confinement in the MRI scanner, interdigital contrast injection, and the overall experience [5-point Likert scale (1: very easy/well tolerable, 5: very difficult/intolerable)]. Adverse events were systematically recorded during a clinical follow-up visit (≥3 mo after CE-MRL) through direct patient inquiry and inspection of the injection sites.</p><p><strong>Results: </strong>CE-MRL was technically successful in all cases. Mean clinical follow-up was 36±19 months (range: 3 to 81 mo). The ease of remaining motionless was rated as very easy or mostly easy in 98.2% of cases, the tolerability of confinement in the MRI scanner as well as tolerable or mostly tolerable in 97.6%, the contrast injection in 85.1%, and the overall experience in 97.6%. In addition, 95.8% of patients would recommend CE-MRL under similar conditions. Five patients reported transient irritation of the skin (n=3, 1.8%) and/or light interdigital pain (n=3, 1.8%) for 1 or 2 days at the injection site. No other adverse events were observed.</p><p><strong>Conclusion: </strong>CE-MRL is well tolerated and safe. Intradermal interdigital contrast injection was the most uncomfortable part of the examination, but was still well tolerated by most patients without any long-term adverse events.</p>","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":"103-110"},"PeriodicalIF":8.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144258111","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 Computed Tomography for the Detection and Characterization of Communications Between the True and the False Lumen in Aortic Dissections.","authors":"Antoine Janin-Manificat, Monica Sigovan, Eduardo Davila, Charles de Bourguignon, Salim Si-Mohamed, Loic Boussel, Benoit Cosset, Yoad Yagil, Antoine Millon, Philippe Douek, Sara Boccalini","doi":"10.1097/RLI.0000000000001221","DOIUrl":"10.1097/RLI.0000000000001221","url":null,"abstract":"<p><strong>Objectives: </strong>To compare the performance of conventional CT (conv-CT) and spectral CT (spectral-CT) for the detection and characterization of communications between the true (TL) and false lumen (FL) in aortic dissections, using 4D flow MRI as the reference.</p><p><strong>Materials and methods: </strong>Eighteen patients with type A and type B aortic dissection who underwent 4D flow MRI, conv-CT and spectral-CT were retrospectively analyzed. For each patient, the examinations closest in time, without any intervention in-between, were retrieved and subjectively analyzed by 2 observers, independently for conv-CT and in consensus for MRI and spectral-CT. Communications between the two lumina were identified as: focal alterations in velocities corresponding to jet flows on 4D flow; both intimal tears and/or focal changes of contrast concentration corresponding to jet flows on conv-CT and spectral-CT. The number and location of communications were noted. The direction of the flow was assessed whenever the jet flow was visible. The performance of conventional and spectral-CT was calculated.</p><p><strong>Results: </strong>Of the 176 communications detected with 4D flow, spectral-CT allowed visualization of 122(69%) compared with 58 (33%) for observer-1 and 38 (22%) for observer-2 for conv-CT, yielding an accuracy twice as high (63% vs 29% to 30%).Only jet flows, without visible intimal tears, were detected in 0 and 77 (63%) cases for conv-CT and spectral-CT, respectively.The flow was unidirectional FL-TL in 2 cases for MRI and spectral-CT and 1 case for conv-CT, bidirectional in 5 and 3 cases for MRI and spectral-CT, respectively. In all other cases, the direction was TL-FL.</p><p><strong>Conclusion: </strong>Spectral-CT outperformed conv-CT for the detection of communications between TL and FL in aortic dissections. Spectral-CT allowed for direct visualization of flow jets, and their direction, through intimal tears.</p>","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":"136-144"},"PeriodicalIF":7.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12736396/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145080262","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":"Dual-Source Dual-Energy Imaging Using Photon-Counting Detector CT for Bone Edema Detection: Leveraging Tin Prefiltration for Improved Spectral Performance.","authors":"Kishore Rajendran, Andrea Ferrero, Elisabeth R Shanblatt, Cynthia H McCollough, Francis I Baffour","doi":"10.1097/RLI.0000000000001201","DOIUrl":"10.1097/RLI.0000000000001201","url":null,"abstract":"<p><strong>Objectives: </strong>The aims of the study were to evaluate the spectral performance of an investigational dual-source (DS) scan mode using a tin (Sn) filter on the B-subsystem of a clinical photon-counting detector (PCD) CT system and to demonstrate improved material decomposition performance using clinical examples of bone imaging tasks.</p><p><strong>Materials and methods: </strong>Calcium inserts (Ca 100, 200 and 300 mg/cc) were placed in water phantoms (30-, 40-, and 50-cm lateral diameter) and scanned on clinical PCD-CT (NAEOTOM Alpha, Siemens) using DS spectral scan mode (QuantumPeak). Two tube potential configurations (70/Sn150 kV and 90/Sn150 kV) were used to scan the phantoms (11 mGy to 41 mGy volume CT dose index). The phantoms were also scanned using the single-source (SS) PCD-CT scan mode at 120 kV and 140 kV tube potential, and on a DS energy-integrating detector (EID) CT (SOMATOM Force, Siemens) for quantitative comparison. CT images (from SS-PCD-CT, DS-PCD-CT, and DS-EID-CT) were reconstructed using a quantitative kernel (Qr40) at a 2-mm section thickness using iterative reconstruction strength 1. Spectral separation was quantified using the dual-energy ratio (DER) of Ca inserts and using mean absolute percent error (MAPE) of Ca mass density obtained from Ca/water material decomposition. To demonstrate clinical feasibility, 4 patients were scanned using DS-PCD-CT under an institutional review board-approved study. Bone edema maps were reconstructed from DS-PCD-CT and compared with the corresponding clinical imaging exam of the same patients (MRI or DS-EID-CT).</p><p><strong>Results: </strong>DS-PCD-CT at 70/Sn150 kV for Ca 100 mg/cc showed the highest mean DER (2.49 and 2.56 at 30 and 40 cm, respectively) among all scan configurations. For the 50-cm phantom at Ca 100 mg/cc, DS-PCD-CT at 90/Sn150 kV showed highest mean DER (1.88), followed by DS-EID-CT at 90/Sn 150 kV (1.87) and SS-PCD-CT at 140 kV (1.78). The MAPE values for DS-PCD-CT were consistently lower across all phantom sizes (MAPE max. of 1.44%) compared to SS-PCD-CT (MAPE max. 3.97%) and DS-EID-CT (MAPE max. 3.68%). Qualitatively, patient images illustrated bone edema depiction on DS-PCD-CT comparable to clinical MR images, and more precise edema depiction compared to DS-EID-CT images at the site of fractures and intramedullary lesions, and with fewer artifacts.</p><p><strong>Conclusions: </strong>DS-PCD-CT showed superior spectral performance for calcium imaging tasks compared to SS-PCD-CT and DS-EID-CT.</p>","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":"68-74"},"PeriodicalIF":8.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144010127","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 α v β 6 /α v β 1 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":"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 α v β 6 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 α v β 6 integrin-targeted positron emission tomography (PET) and collagen-specific magnetic resonance imaging (MRI) to measure target expression/engagement and liver fibrosis reduction with a α v β 6 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 α v β 6 /α v β 1 . 68 Ga-DOTA-R01-MG, an α v β 6 -specific PET probe, was used to noninvasively measure α v β 6 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>68 Ga-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 α v β 6 /α v β 1 inhibitor 1 hour before imaging significantly decreased liver PET uptake in BDL rats (31%, P  = 0.012). Two weeks of daily dosing with an α v β 6 /α v β 1 inhibitor attenuated α v β 6 expression in BDL rat liver as assessed by α v β 6 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 ΔR 1  = 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":"59-67"},"PeriodicalIF":7.9,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12354051/pdf/","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":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Photon-Counting Chest CT at Radiography-Comparable Dose Levels: Impact on Opportunistic Visual and Semiautomated Coronary Calcium Quantification.","authors":"Jonas Kroschke, Bjarne Kerber, Matthias Eberhard, Falko Ensle, Thomas Frauenfelder, Lisa Jungblut","doi":"10.1097/RLI.0000000000001199","DOIUrl":"10.1097/RLI.0000000000001199","url":null,"abstract":"<p><strong>Objectives: </strong>The introduction of photon-counting detector computed tomography (PCCT) has allowed for significant dose reductions compared to energy-integrating-detector CT, making it particularly relevant for applications such as lung cancer screening. Coronary artery calcification is an important incidental finding in lung cancer screening, warranting attention in this context. This study aims to assess the impact of dose reduction to levels comparable to that of a chest radiography on opportunistic evaluation of coronary artery calcification on PCCTs of the chest.</p><p><strong>Materials and methods: </strong>Sixty-eight out of 115 patients with age >45 years and body mass index ≤30 kg/m 2 undergoing noncontrast low- and chest-radiography-comparable-dose PCCT in the same session were included. Scans were performed at 100 kVp with image quality settings 12 (low-dose) and 2 (radiography-comparable-dose). Visual calcium scoring was conducted by 2 readers using 2 scoring approaches (CAD-RADS 2.0 and Shemesh). Semiautomated quantitative analysis was performed using commercially available software. Image quality was evaluated using 5-point Likert scales.</p><p><strong>Results: </strong>Sixty-eight patients (65.9 ± 8.6 years; 49 men) were subjected to evaluation. CTDI was lower for radiography-dose scans (0.11 mGy vs 0.68 mGy; P  < 0.001). Image quality was found to be inferior for radiography-dose scans (4.01 vs 2.03; P  < 0.001). In both visual scoring approaches, coronary calcification was scored significantly lower in radiography-dose scans ( P  < 0.001 for both) with almost perfect reader agreement (CAD-RADS score Cohen's kappa =0.82; Shemesh score Cohen's kappa =0.81), most importantly reclassification from mild to absent occurred for CAD-RADS score in 31%/21% of cases and for Shemesh score in 23%/15% of cases (reader 1/reader 2). Semiautomated assessment showed no significant differences between low and radiography dose ( P  = 0.121). Strong correlation between scores (Pearson's r = 0.98, P  < 0.001) with good agreement (Cohen's kappa =0.61) was found.</p><p><strong>Conclusions: </strong>Coronary artery calcifications are underestimated on radiography-dose PCCT visually, whereas semiautomatic analysis provides more robust results. Visual underestimation of coronary artery calcification in low-dose imaging is further amplified with the additional dose reduction to radiography-comparable dose levels, indicating that while estimation of high cardiovascular risk is feasible, exclusion of such risk is not possible.</p>","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":"41-48"},"PeriodicalIF":7.9,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12662135/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144015682","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":"Fixed Versus Patient-Specific Trigger Delay in High-Pitch Computed Tomography Angiography of the Aorta Prior to Transcatheter Aortic Valve Implantation: Assessment of Image Quality and Homogeneity of Vessel Enhancement.","authors":"Sidre Sahin-Uzuner, Foroud Aghapour Zangeneh, Goncalo De Almeida, Oezlem Krzystek, Maria Paslak, Jakob Heimer, Ralf Gutjahr, Thomas Sartoretti, Tilo Niemann, André Euler","doi":"10.1097/RLI.0000000000001176","DOIUrl":"10.1097/RLI.0000000000001176","url":null,"abstract":"<p><strong>Objective: </strong>The aim of the study is to compare the image quality and homogeneity of vessel enhancement in high-pitch CT-angiography of the aorta (CTA) prior to transcatheter aortic valve implantation between bolus tracking with a fixed trigger delay and bolus tracking with a patient-specific trigger delay.</p><p><strong>Materials and methods: </strong>In this retrospective study, consecutive patients who received a CTA of the aorta prior to transcatheter aortic valve implantation between January 2023 and June 2024 were included. Patients were imaged using either bolus tracking and a fixed trigger delay (Group A; 15 seconds) or bolus tracking and a patient-specific trigger delay (Group B; FAST Bolus; Siemens Healthineers AG). The same contrast injection and scan protocol were used in both groups. Vessel enhancement was measured at multiple craniocaudal locations. Subjective image quality was assessed by 2 readers using 5-point Likert scales. Likert scores were analyzed using Wilcoxon rank-sum tests. Enhancement was assessed with a mixed-effects model.</p><p><strong>Results: </strong>Sixty-five patients (28 females) were assessed in each group. Patient demographics (both 74 ± 12 years; P  = 0.58, body mass index: 26.0 vs 26.2 kg/m 2 ; P  = 0.79) and radiation dose (CTDI vol : 3.4 vs 3.5 mGy; P  = 0.55) did not differ significantly between the two groups. Mean CT attenuation was 489 HU versus 469 HU in the ascending aorta and 428 HU versus 464 HU in the common femoral artery for fixed and patient-specific delays, respectively. Enhancement in the femoral arteries was significantly lower in the fixed delay group ( P  < 0.05), while there was no significant difference at other vessel locations. Diagnostic image quality and enhancement at the femoral artery were rated significantly better for the patient-specific trigger delay by one reader (both P  < 0.05).</p><p><strong>Conclusions: </strong>Bolus tracking with a patient-specific trigger delay improved the craniocaudal homogeneity of vessel enhancement and subjective image quality at the distal access site as compared to bolus tracking with a fixed trigger delay in high-pitch CTA prior to TAVI.</p>","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":"26-31"},"PeriodicalIF":8.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12662131/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143669842","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":"Myocardial Late Enhancement With Photon-Counting Detector CT in Spontaneous Coronary Artery Dissection: Prospective Comparison With Cardiac MRI.","authors":"Konstantin Klambauer, Ernst Klotz, Lukas J Moser, Tobias Kälin, Andrea Biondo, Victor Schweiger, Victor Mergen, Costanza Lisi, Michael Würdinger, Rabea Schlenker, Davide Di Vece, Alexander Gotschy, Martin Reiner, Jelena-R Ghadri, Verena C Wilzeck, Matthias Eberhard, Christian Templin, Robert Manka, Hatem Alkadhi","doi":"10.1097/RLI.0000000000001203","DOIUrl":"10.1097/RLI.0000000000001203","url":null,"abstract":"<p><strong>Objectives: </strong>Spontaneous coronary artery dissection (SCAD) is a rare cause of acute coronary syndrome and myocardial infarction. Accurate diagnosis is crucial for appropriate management. This study aimed to compare late enhancement (LE) imaging using photon-counting detector (PCD)-CT with cardiac MRI in patients with SCAD in the acute phase and during follow-up and to introduce a novel approach for visualizing myocardial extracellular volume (ECV) distribution in the myocardium.</p><p><strong>Materials and methods: </strong>This single-center prospective study enrolled patients with SCAD diagnosed with invasive coronary angiography. LE iodine imaging with spectral dual-source PCD-CT and cardiac MRI was performed early after symptom onset and at short-term follow-up. CT included coronary angiography and LE imaging (5 minutes after contrast). LE CT was assessed using the combination of conventional LE images, overlay images, polar maps, and with newly developed atlas maps. Atlas maps represent 2-dimensional maps with prefiltering applied to enable a simpler and more intuitive reading of ECV distribution across the myocardium. Cardiac MRI served as the reference standard for identifying pathologic myocardial segments based on late gadolinium enhancement (LGE) and edema on T2-weighted and T2-mapping images. Agreement between modalities was evaluated using Cohen's κ.</p><p><strong>Results: </strong>Seventeen patients (median age, 44 years [interquartile range, 36-52]; 11 women) underwent 24 LE CT and cardiac MRI scans. Sixteen patients (median age, 44 years; 10 women) underwent acute phase imaging (median 6 days after symptom onset), and 8 patients (median age, 45 years; 6 women) underwent follow-up imaging (median 120 days after symptom onset). Atlas maps were helpful in detecting segments with pathological ECV and to adjudicate corresponding myocardial segments. Agreement between LE CT with LGE cardiac MRI was strong in the acute phase (κ = 0.832), improving to almost perfect when comparing LE-CT with both LGE and edema in cardiac MRI (κ = 0.944). At follow-up imaging, agreement further improved as edema resolved (κ = 0.956).</p><p><strong>Conclusions: </strong>LE imaging with PCD-CT demonstrated strong agreement with cardiac MRI for detecting myocardial injury in SCAD, which further improved at follow-up when edema resolved. Newly introduced atlas maps proved useful for a simple and intuitive visualization of myocardial injury.</p>","PeriodicalId":14486,"journal":{"name":"Investigative Radiology","volume":" ","pages":"32-40"},"PeriodicalIF":7.9,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12662126/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144063810","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}