Objectives:To evaluate if a high-resolution photon-counting-detector computed tomography (PCD-CT) system with a 1024 × 1024 matrix reconstruction can improve the visualization of fine structures in the lungs compared to conventional high-resolution CT (HRCT).Materials and Methods: Twenty-two adult patients referred for clinical chest HRCT (mean CTDI vol 13.58 mGy) underwent additional dose-matched PCD CT (mean CTDI vol 13.37mGy ) after written informed consent. CT images were reconstructed at a slice thickness of 1.5 mm and an image increment of 1mm with our routine HRCT reconstruction kernels (B46 and Bv49) at 512 and 1024 matrix sizes for conventional energy-integrating-detector (EID) CT scans. For PCD CT, routine B46 kernel and an additional sharp kernel (Q65, unavailable for EID) images were reconstructed at 1024 matrix size. Two thoracic radiologists compared images from EID and PCD-CT noting the highest level bronchus clearly identified in each lobe of the right lung, and rating bronchial wall conspicuity of 3rd and 4th order bronchi. Lung nodules were also compared to the B46/EID/512 images using a 5-point Likert-scale. Statistical analysis was performed using a Wilcoxon signed rank test with a p <0.05 considered significant.Results: Compared to B46/EID/512, readers detected higher order bronchi using B46/PCD/1024 and Q65/PCD/1024 images for every lung lobe (p<0.0015), but in only the right middle lobe for B46/EID/1024 (p=0.007). Readers were able to better identify bronchial walls of the 3rd and 4th order bronchi better using the Q65/PCD/1024 images (mean Likert-scores of 1.1 and 1.5), which was significantly higher compared to B46/EID/1024 or B46/PCD/1024 images (mean difference 0.8; p<0.0001). The Q65/PCD/1024 images had a mean nodule score of 1 ± 1.3 for Reader 1, and −0.1 (0.9) for Reader 2, with one reader having improved nodule evaluation scores for both PCD kernels (p<0.001), and the other reader not identifying any increased advantage over B46/EID/ 1024 (p = 1.0). Conclusion:High resolution lung PCD CT with 1024 image matrix reconstruction increased radiologists' ability to visualize higher order bronchi and bronchial walls without compromising
Quantitative analysis of thin-section CT of the chest has a growing role in the clinical evaluation and management of diffuse lung diseases. This heterogeneous group includes diseases with markedly different prognoses and treatment options. Quantitative tools can assist in both accurate diagnosis and longitudinal management by improving characterization and quantification of disease and increasing the reproducibility of disease severity assessment. Furthermore, a quantitative index of disease severity may serve as a useful tool or surrogate endpoint in evaluating treatment efficacy. The authors explore the role of quantitative imaging tools in the evaluation and management of diffuse lung diseases. Lung parenchymal features can be classified with threshold, histogram, morphologic, and texture-analysis-based methods. Quantitative CT analysis has been applied in obstructive, infiltrative, and restrictive pulmonary diseases including emphysema, cystic fibrosis, asthma, idiopathic pulmonary fibrosis, hypersensitivity pneumonitis, connective tissue-related interstitial lung disease, and combined pulmonary fibrosis and emphysema. Some challenges limiting the development and practical application of current quantitative analysis tools include the quality of training data, lack of standard criteria to validate the accuracy of the results, and lack of real-world assessments of the impact on outcomes. Artifacts such as patient motion or metallic beam hardening, variation in inspiratory effort, differences in image acquisition and reconstruction techniques, or inaccurate preprocessing steps such as segmentation of anatomic structures may lead to inaccurate classification. Despite these challenges, as new techniques emerge, quantitative analysis is developing into a viable tool to supplement the traditional visual assessment of diffuse lung diseases and to provide decision support regarding diagnosis, prognosis, and longitudinal evaluation of disease. ©
Two isomeric binuclear ligands PBTPA and MBTPA and their copper(II) complexes were prepared and examined for hydrolysis of a model phosphodiester substrate: bis(p-nitrophenyl)phosphate. A bell-shaped pH vs rate profile, which is in agreement with one mechanism proposed for bimetallonucleases/phosphatases, was observed for the binuclear complex of copper(II) and PBTPA. At pH 8.4, a maximum rate of 1.14 x 10(-6) s(-1)--more than 10(4)-fold over uncatalyzed reactions--was achieved. However, the analogous complex of MBTPA did not show significant rate enhancement. The binuclear complex of copper(II) and PBTPA also showed 10-fold acceleration over mononuclear complex of copper(II) and tris(2-pyridylmethyl)amine (TPA) catalyzed reaction. A phage phiX174 DNA assay showed that the complex of copper(II) and PBTPA promoted supercoiled phage phiX174 DNA relaxation under both aerobic and anaerobic conditions, in contrast to the hydrolytic inactivity of the mononuclear complex of copper(II) and TPA.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.