Journal of Computer Assisted Tomography最新文献

{"title":"0.55 T Magnetic Resonance Imaging in the Abdomen and Pelvis: Opportunities and Challenges.","authors":"Michael A Ohliger, Cheng Hong, Kang Wang, Yang Yang","doi":"10.1097/RCT.0000000000001895","DOIUrl":"10.1097/RCT.0000000000001895","url":null,"abstract":"<p><p>As applications of MRI in the abdomen and pelvis have increased, access to MRI scanners has become more crucial. 0.55 T MRI scanners can potentially improve access by reducing the costs of MR systems and simplifying their siting requirements. These savings come with important tradeoffs, most notably decreased SNR efficiency. Decreases in SNR can be ameliorated to some degree by shorter T1 (faster repetition time), longer T2* (reduced susceptibility artifacts), and higher gadolinium relaxivity, which are found at lower fields. Reduced frequency separation between fat and water presents a particular challenge in imaging the abdomen and pelvis. In this article, we review how MRI at 0.55 T affects abdominal and pelvic imaging and discuss clinical examples of the liver, kidney, bile ducts, uterus, and ovary. We illustrate how metal artifacts are reduced at 0.55 T and discuss how deep learning image reconstructions, combined with free-breathing techniques, can overcome some of the limitations imposed by reduced SNR. We discuss future challenges and opportunities in this field, leveraging technological advances from other fields to bring MRI to more people who need it.</p>","PeriodicalId":15402,"journal":{"name":"Journal of Computer Assisted Tomography","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148793832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Guest Editor Foreword on Mid and Low-Field MR Imaging Systems.","authors":"Luke Ginocchio, Hersh Chandarana","doi":"10.1097/RCT.0000000000001859","DOIUrl":"10.1097/RCT.0000000000001859","url":null,"abstract":"","PeriodicalId":15402,"journal":{"name":"Journal of Computer Assisted Tomography","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147326032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Whole-Body MRI of Primary Bone Tumors.","authors":"Vivek Kiyawat, Jonathan Gibson, Eelin Tan, A Mark Davies, Rajesh Botchu","doi":"10.1097/RCT.0000000000001922","DOIUrl":"https://doi.org/10.1097/RCT.0000000000001922","url":null,"abstract":"<p><p>Magnetic resonance imaging (MRI) is the established gold standard for the staging of primary bone tumors; however, conventional protocols typically use a site-specific model supplemented by ionizing radiation for systemic screening. Recent advancements in whole-body MRI (WB-MRI) have enabled a \"marrow-first\" diagnostic approach, allowing for the comprehensive assessment of the primary intraosseous lesion and the entire skeleton in a single, radiation-free study. Technical developments, including Dixon fat suppression and diffusion-weighted imaging (DWI), have significantly enhanced the detection of occult skip metastases, which occur in ∼7.5% of high-grade osteosarcomas and 4.5% of Ewing sarcomas. Beyond malignant staging, WB-MRI offers distinct advantages for the longitudinal surveillance of syndromic conditions such as Ollier disease and hereditary multiple exostoses, where it facilitates a shift toward patient-initiated, symptom-led monitoring. Despite these advances, challenges remain, specifically the \"chest gap\" in pulmonary nodule detection and the potential for false positives from hematopoietic marrow mimics. This review discusses the technical principles, clinical applications, and diagnostic pitfalls of WB-MRI in bone tumors, emphasizing its role in optimizing staging accuracy while minimizing cumulative radiation exposure.</p>","PeriodicalId":15402,"journal":{"name":"Journal of Computer Assisted Tomography","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148865009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of an Algorithm to Estimate Fat-Free Mass to Optimize Contrast Injection for Computed Tomography Imaging of the Liver.","authors":"Natalie Heracleous, Hugues Brat, Benoit Dufour, Benoit Rizk, Cyril Thouly, Federica Zanca","doi":"10.1097/RCT.0000000000001877","DOIUrl":"10.1097/RCT.0000000000001877","url":null,"abstract":"<p><strong>Objectives: </strong>Contrast-enhanced computed tomography (CT) is central to liver imaging. Inadequate enhancement can compromise diagnostic accuracy and impact treatment decisions. Fat-free mass (FFM) has emerged as a key predictor of liver enhancement quality, enabling personalized contrast protocols. However, direct FFM measurement is impractical in clinical settings due to equipment costs and time requirements.</p><p><strong>Methods: </strong>We developed a simple machine learning (ML) algorithm to estimate FFM using routinely available patient characteristics, including weight, height, age, and sex. A data set of 689 patients with hepatic CT scans was used to train, validate, and test the algorithm. FFM was benchmarked against measurements from a bioelectrical impedance meter (Biotekna, Italy). Model performance was evaluated through K-fold validation, yielding metrics such as R-squared ( R2 ), mean absolute percentage error (MAPE), and root mean squared error (RMSE). Clinical validation was also performed by measuring the contrast enhancement after the algorithm was implemented using 265 cases.</p><p><strong>Results: </strong>The ML model demonstrated high accuracy in predicting FFM ( R2 =0.915±0.019; MAPE=0.033±0.003). Clinical validation after model implementation in clinical practice showed optimal liver enhancement, corresponding to acceptable image quality, in 89% of cases (235), with a mean enhancement centered at 53 Hounsfield units. The model outperformed existing FFM estimation formulas, demonstrating superior accuracy and generalizability across diverse populations.</p><p><strong>Conclusions: </strong>Our ML-based FFM estimation model facilitates personalized contrast protocols, eliminating the need for expensive equipment and reducing procedural complexity. This approach optimizes liver imaging quality, enhances lesion detection, and supports treatment planning.</p>","PeriodicalId":15402,"journal":{"name":"Journal of Computer Assisted Tomography","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147772833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Noise-Matched Blending Level Selection for 1024-Matrix CT Images Using Hybrid-Iterative Reconstruction: Comparison With 512-Matrix Images.","authors":"Shingo Omata, Yoshifumi Noda, Yukako Iritani, Naoto Ozawa, Nobuyuki Kawai, Tetsuro Kaga, Yukiko Takai, Akio Ito, Masashi Asano, Takeshi Iwata, Toshiharu Miyoshi, Abdelazim E Elhelaly, Hirohiko Imai, Hiroki Kato, Masayuki Matsuo","doi":"10.1097/RCT.0000000000001878","DOIUrl":"10.1097/RCT.0000000000001878","url":null,"abstract":"<p><strong>Objective: </strong>To identify the noise-matched hybrid-iterative reconstruction (IR) blending level for 1024-matrix images with noise equivalent to that of 512-matrix images while preserving comparable image quality.</p><p><strong>Methods: </strong>In the phantom study, we identified the noise-matched hybrid-IR blending level for 1024-matrix images that achieved a noise level equivalent to 512-matrix images reconstructed with adaptive statistical iterative reconstruction-Veo (ASiR-V) 30%. This retrospective study included 63 patients (40 women; median age: 74y) who had undergone single-energy pancreatic protocol computed tomography (CT) from August 2023 to June 2024. For each patient, 3 image sets at the pancreatic phase were reconstructed: 512-matrix with ASiR-V 30% (group 1), 1024-matrix with ASiR-V 30% (group 2), and 1024-matrix with the noise-matched ASiR-V blending level (group 3). Background noise was measured as the SD of CT attenuation in the abdominal subcutaneous fat. Edge-rise slope (ERS) at the pancreas-fat interface was used to quantify edge sharpness. Two radiologists assessed overall image quality using a 5-point scale.</p><p><strong>Results: </strong>The phantom study identified 60% as the noise-matched blending level for group 3. Background noise was significantly lower in the order of groups 3, 1, and 2, respectively ( P < 0.001). ERS value was significantly higher in the order of groups 2, 3, and 1, respectively ( P < 0.001). Overall image quality was significantly superior in the order of groups 3, 1, and 2, respectively ( P < 0.001 for both radiologists).</p><p><strong>Conclusions: </strong>Increasing the matrix size leads to greater image noise with conventional reconstruction; however, applying a noise-matched hybrid-IR blending level allowed 1024-matrix images to maintain image quality while improving edge sharpness.</p>","PeriodicalId":15402,"journal":{"name":"Journal of Computer Assisted Tomography","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147868130","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Commentary: Foreword From the Editor-in-Chief for Guest Section on Low Field Strength MRI.","authors":"Eric P Tamm","doi":"10.1097/RCT.0000000000001875","DOIUrl":"10.1097/RCT.0000000000001875","url":null,"abstract":"","PeriodicalId":15402,"journal":{"name":"Journal of Computer Assisted Tomography","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147838468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Spiderweb Sign: A Pulmonary CT Finding After Intranodal Lymphangiography.","authors":"Doyle Lang, Sadeer J Alzubaidi, Sayf Al-Katib","doi":"10.1097/RCT.0000000000001920","DOIUrl":"https://doi.org/10.1097/RCT.0000000000001920","url":null,"abstract":"<p><p>This case series describes an imaging finding seen in patients following lymphangiography-lace-like hyperdensities outlining the pulmonic lymphatic pathways-termed the spiderweb sign. In a retrospective review of patients who underwent lymphangiograms at a large tertiary care hospital from January 2022 to December 2025, 11 patients had CT thorax images within 1 week of the procedure, and 4 of these patients demonstrated the spiderweb sign. Specifically, the spiderweb sign manifests as hyperdense linear opacities outlining the interlobular septa, peribronchovascular interstitium, and visceral pleura. We present the 4 representative cases illustrating the imaging findings. For the cohort, procedural parameters were collected to assess associations with the presence or absence of the imaging finding, but no definitive association was found. While the exact mechanism remains unclear, these findings parallel patterns seen in prior studies and appear clinically benign. An additional literature review of pulmonary findings following lymphangiography was conducted to contextualize the spiderweb sign. Awareness of these postprocedural imaging findings as expected findings rather than developing pathology is essential to prevent misinterpretation. Larger multicenter studies are needed to clarify procedural factors and the underlying pathophysiology.</p>","PeriodicalId":15402,"journal":{"name":"Journal of Computer Assisted Tomography","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148865040","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of 18 F-FDG PET/CT Imaging Features of Nodal Diffuse Large B-Cell Lymphoma and Follicular Lymphoma.","authors":"Hao Yu, Chaowei Li, Fei Jin, Wenwen Jiang, Yudong Sui, Lei Zeng, Yanli Wang, Na Fang","doi":"10.1097/RCT.0000000000001872","DOIUrl":"10.1097/RCT.0000000000001872","url":null,"abstract":"<p><strong>Objective: </strong>In this study, we aimed to investigate the value of 18 F-fluorodeoxyglucose positron emission tomography/computed tomography ( 18 F-FDG PET/CT) in the differential diagnosis of nodal diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL) and to detect early FL transformation.</p><p><strong>Methods: </strong>We retrospectively enrolled 141 and 56 patients with pathologically confirmed DLBCL and FL, respectively, who underwent 18 F-FDG PET/CT before treatment. The most metabolically active lymph nodes in each patient were selected to compare the imaging characteristics (including shape, size, density, adjacent tissue structures, and metabolism) between DLBCL and FL. Logistic regression was performed to identify the independent risk factors for DLBCL, and receiver operating characteristic (ROC) curve analysis was used to assess the diagnostic value of the different parameters.</p><p><strong>Results: </strong>Compared with DLBCL, FL was more likely to affect the para-iliac (62.5% vs. 32.6%, P <0.05) and inguinal (50.0% vs. 28.4%, P <0.05) regions. Significant differences ( P <0.05) were observed between DLBCL and FL in lesion fusion, necrosis, surrounding fat stranding, adjacent organ involvement, nonround shape, SUV max , SUV peak , SUV mean , SUL max , SUL peak , SUL mean , lesion SUV max /liver SUV max (L/L), lesion SUV max /mediastinum SUV max (L/M), and total lesion glycolysis (TLG). Multivariate logistic regression analysis identified SUV max >12.35, necrosis, and surrounding fat stranding as independent risk factors of DLBCL. The diagnostic model achieved an area under the curve (AUC) of 0.882, with a sensitivity of 69.5% and specificity of 94.6% for diagnosing DLBCL.</p><p><strong>Conclusions: </strong>¹⁸F-FDG PET/CT may provide greater diagnostic value in distinguishing nodal DLBCL from FL and probably aid in the early detection of FL transformation and thereby guide timely clinical intervention, which could improve the prognosis.</p>","PeriodicalId":15402,"journal":{"name":"Journal of Computer Assisted Tomography","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13574342/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147772781","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Commentary: Extending Opportunistic Aortic Calcium Scoring Beyond Noncontrast CT.","authors":"Prashant Nagpal, Vinit Baliyan","doi":"10.1097/RCT.0000000000001913","DOIUrl":"10.1097/RCT.0000000000001913","url":null,"abstract":"","PeriodicalId":15402,"journal":{"name":"Journal of Computer Assisted Tomography","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148430539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Association of Imaging-Defined Deep Invasion and Tumor Volume With Clinical Cervical Lymph Node Metastasis in Hypopharyngeal Carcinoma.","authors":"Hinano Anaba, Yohei Morishita, Ryo Ishii, Takuma Usuzaki, Tomo Kinoshita, Yoshitaka Toyama, Akira Ohkoshi, Yukio Katori, Kei Takase","doi":"10.1097/RCT.0000000000001919","DOIUrl":"https://doi.org/10.1097/RCT.0000000000001919","url":null,"abstract":"<p><strong>Objective: </strong>Deep tumor invasion is a recognized pathologic risk factor for cervical lymph node metastasis in patients with hypopharyngeal carcinoma, but the relationship between imaging findings of the primary tumor and clinical lymph node metastasis has not been fully defined. In this study, we assessed whether imaging-defined deep invasion and tumor volume are associated with clinical lymph node metastasis.</p><p><strong>Methods: </strong>This retrospective study included 142 consecutive patients with newly diagnosed hypopharyngeal squamous cell carcinoma who underwent contrast-enhanced CT and MRI before treatment. Deep anterior wall (paraglottic space) invasion was graded according to tumor contact with the superior laryngeal neurovascular bundle. Deep posterior wall invasion was evaluated on MRI. Tumor diameter and volume were measured, and associations with lymph node status were assessed. Multivariable logistic regression was used to identify independent factors of clinical lymph node metastasis.</p><p><strong>Results: </strong>Clinical cervical lymph node metastasis was present in 78/142 patients (54.9%). The median tumor volume was greater in node-positive than in node-negative tumors (3.92 vs. 0.22 cm3, P<0.001). Deep anterior wall invasion was detected in 82 patients, and was more common in node-positive cases (73.1% vs. 39.1%, P<0.001). In multivariable analysis, deep anterior wall invasion (OR=2.42; 95% CI: 1.02-5.78; P=0.04) and tumor volume (OR=1.32 per cm3; 95% CI: 1.08-1.73; P=0.025) were independently associated with clinical cervical lymph node metastasis.</p><p><strong>Conclusion: </strong>Deep anterior wall invasion and larger tumor volume were associated with clinical cervical lymph node metastasis in hypopharyngeal carcinoma.</p>","PeriodicalId":15402,"journal":{"name":"Journal of Computer Assisted Tomography","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148840499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}