CT parameters

  • 文章类型: Journal Article
    评估后韧带复合体(PLC)的完整性,作为表征不稳定胸腰椎骨折(TLF)的关键要素,具有挑战性,但对治疗的选择至关重要。
    如何使用计算机断层扫描(CT)的组合参数创建可重复的评分来预测不明显的PLC损伤。CT参数与PLC状态的关系。
    急性创伤性TLF患者神经系统完整的回顾性分析,在72小时内接受CT和磁共振成像(MRI),在2016年1月至2022年之间的单个机构的急诊科。四名研究人员对MRI的CT和PLC完整性独立评估了11个参数。评估了CT参数的中间可靠性,并使用多变量逻辑回归系数创建两个风险评分来预测CT上的PLC损伤。
    包括154名患者,其中62例患有PLC损伤。所有CT测量都具有出色或良好的评分者间可靠性。椎板或椎弓根水平骨折(HLPF)的患者,棘突骨折(SPF)和棘突间距离扩大(IDW)与PLC损伤呈正相关(分别为p<0.001,p<0.001和p=0.045)。风险评分2(RS2),其中只包括有统计学意义的变量,共有75.9%的正确分类(p<0.001),评估MRI中检测到的PLC损伤的敏感性为71.0%,特异性为78.3%。
    在CT测量方案中预先建立的标准化程序是有效的。与早期发现一样,这三次CT测量显示与PLC损伤呈正相关,从而加强了以往研究的结论。与上述CT检查结果的可靠性相比,分数不太精确。
    UNASSIGNED: Assessing the integrity of the posterior ligament complex (PLC), as a key element in the characterization of an unstable Thoracolumbar fracture (TLF), is challenging, but crucial in the choice of treatment.
    UNASSIGNED: How to create a reproducible score using combined parameters of Computed Tomography (CT) to predict nonobvious PLC injury. How CT parameters relate with PLC status.
    UNASSIGNED: Retrospective analysis of neurologically intact patients with an acute traumatic TLF, who underwent CT and Magnetic Resonance Imaging (MRI) within 72 h, in the Emergency Department of a single institution between January 2016 and 2022. Four investigators rated independently 11 parameters on CT and PLC integrity on MRI. The interrater reliability of the CT parameters was evaluated, and two risk scores were created to predict PLC injury on CT using the coefficients of the multivariate logistic regression.
    UNASSIGNED: 154 patients were included, of which 62 with PLC injury. All CT measurements had excellent or good interrater reliability. Patients with Horizontal Fracture of the lamina or pedicle (HLPF), Spinous process fracture (SPF) and Interspinous Distance Widening (IDW) were positively associated with PLC injury (p < 0.001, p < 0.001 and p = 0.045, respectively). Risk Score 2 (RS2), which included only statistically significant variables, had a total of 75.9% of correct classifications (p < 0.001), with a sensitivity of 71.0% and specificity of 78.3% to estimate PLC injury detected in the MRI.
    UNASSIGNED: Standardized procedures pre-established in the CT measurement protocol were effective. Identically to early findings, those three CT measurements showed a positive relation to PLC injury, thus enhancing the conclusions of previous studies. Comparing to the reliability of the CT findings above mentioned, the score was less precise.
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  • 文章类型: Journal Article
    影像组学认为,放射摄影图像的量化特征反映了潜在的病理生理学。肺癌(LC)是一种常见的癌症,导致死亡。计算机断层扫描(CT)图像的切片厚度(ST)是影响肿瘤学影像组学特征(RF)可概括性的关键因素。缺乏ST如何影响LC中RF的变异性的研究。本研究有助于确定受ST变化影响的特定RF类别,并为在LC领域使用RF的研究人员和临床医生提供有价值的见解。因此,本研究的目的是评估ST对肺肿瘤CT-RF可重复性的影响。
    这是一项前瞻性研究,包括32例确诊为肺肿瘤的组织病理学诊断。使用128切口CT(PhilipsHealthCare)进行对比增强CT(CECT)胸部检查。图像采集采用5-mm和2mmST进行回顾性重建。从两个ST的CECT胸部图像中提取RF。我们进行了配对t检验以评估两种厚度之间的RF差异。进行Lin's一致性相关系数(CCC)以确定两种厚度之间的RF再现性。
    在107RF中,当比较两个ST时,66(61.6%)表现出统计学显著差异(p<0.05),而41(38.3%)RF在两个ST测量之间没有表现出显著差异(p>0.05)。29个特征(CCC≥0.90)显示出优异到中等的再现性,78个特征(CCC≤0.90)显示重现性差。在7个射频类别中,基于形状的特征(57.1%)显示出最大的再现性,而基于NGTDM的特征显示出可忽略的再现性.
    ST对肺肿瘤的大部分CT-RF有显著影响。基于形状的特征(57.1%)。与其他射频类别相比,一阶(44.4%)特征显示出最高的再现性。
    UNASSIGNED: Radiomics posits that quantified characteristics from radiographic images reflect underlying pathophysiology. Lung cancer (LC) is one of the prevalent forms of cancer, causing mortality. Slice thickness (ST) of computed tomography (CT) images is a crucial factor influencing the generalizability of radiomic features (RF) in oncology. There is scarcity of research that how ST affects variability of RF in LC. The present study helps in identifying the specific RF categories affected by variations in ST and provides valuable insights for researchers and clinicians working with RF in the field of LC.Hence, aim of the study is to evaluate influence of ST on reproducibility of CT-RF for lung tumors.
    UNASSIGNED: This is a prospective study, 32 patients with confirmed histopathological diagnosis of lung tumors were included. Contrast Enhanced CT (CECT) thorax was performed using a 128- Incisive CT (Philips Health Care). The image acquisition was performed with 5-mm and 2 mm STwas reconstructed retrospectively. RF were extracted from the CECT thorax images of both ST. We conducted a paired t-test to evaluate the disparity in RF between the two thicknesses. Lin\'s Concordance Correlation Coefficient (CCC) was performed to identify the reproducibility of RF between the two thicknesses.
    UNASSIGNED: Out of 107 RF, 66 (61.6%) exhibited a statistically significant distinction (p<0.05) when comparing two ST and while 41 (38.3%) RF did not show significant distinction (p>0.05) between the two ST measurements. 29 features (CCC ≥ 0.90) showed excellent to moderate reproducibility, and 78 features (CCC ≤ 0.90) showed poor reproducibility. Among the 7 RF categories, the shape-based features (57.1%) showed the maximum reproducibility whereas NGTDM-based features showed negligible reproducibility.
    UNASSIGNED: The ST had a notable impact on the majority of CT-RF of lung tumors. Shape based features (57.1%). First order (44.4%) features showed highest reproducibility compared to other RF categories.
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  • 文章类型: Journal Article
    背景:慢性阻塞性肺疾病(COPD)是一种以急性加重和肺功能降低为特征的呼吸系统疾病。这项研究调查了血清标志物(免疫球蛋白M(IgM)和免疫球蛋白A(IgA))之间的联系,胸部计算机断层扫描(CT)扫描结果,和这些发作期间的肺功能指标,旨在提高我们的认识并确定新的诊断指标。
    方法:河北北方学院附属第一医院,我们选择了89例过去两年内急性加重的COPD患者作为急性加重组(AG).同时,96例COPD患者,最初在同一家医院接受治疗,目前认为稳定,被选入稳定组(SG)。两组均行血清IgM和IgA检测,胸部CT检查,和肺功能评估。
    结果:在AG组中,血清IgM水平略低于稳定组(SG),尽管差异无统计学意义(p=0.097)。相反,AG中的血清IgA水平显着低于SG(p<0.001)。AG还显示肺体积明显减少,吸气性肺密度,与SG相比,肺功能指标和肺气肿指数(EI)和空气捕集指数(ATI)的值高得多(均p<0.001)。Pearson相关分析显示,肺容积,平均吸气肺密度,IgA水平与1秒用力呼气量(FEV1)有很强的正相关性,FEV1/强制肺活量(FVC),和弥漫性一氧化碳(DLCO)(各自的r值为0.824、0.841和0.829;所有p<0.001)。相比之下,EI和ATI与FEV1、FEV1/FVC呈显著负相关,和DLCO(r值范围为-0.837至-0.885;所有p<0.001)。
    结论:血清IgA结合胸部CT参数的评估为诊断和评估COPD急性加重提供了有价值的见解。提出了一个简单的临床效用。
    Chronic Obstructive Pulmonary Disease (COPD) is a respiratory condition characterized by acute exacerbations and reduced lung function. This study investigates the link between serum markers (Immunoglobulin M (IgM) and Immunoglobulin A (IgA)), thoracic computed tomography (CT) scan findings, and pulmonary function indexes during these episodes, aiming to improve our understanding and identify new diagnostic indicators.
    From the First Affiliated Hospital of Hebei North University, we selected 89 COPD patients experiencing acute exacerbation within the past two years for our Acute Exacerbation Group (AG). Meanwhile, 96 COPD patients, initially treated at the same hospital and currently deemed stable, were chosen for the Stable Group (SG). Both groups underwent serum IgM and IgA tests, thoracic CT examinations, and pulmonary function assessments.
    In the AG Group, the serum IgM levels were marginally lower than in the Stable Group (SG), though the difference wasn\'t statistically significant (p = 0.097). Conversely, serum IgA levels in the AG were significantly lower than in the SG (p < 0.001). The AG also showed markedly reduced lung volume, inspiratory lung density, and pulmonary function indexes compared to the SG while having considerably higher values for emphysema index (EI) and air trapping index (ATI) (all p < 0.001). Pearson correlation analysis revealed that lung volume, average inspiratory lung density, and IgA levels had strong positive correlations with one-second forced expiratory volume (FEV1), FEV1/forced vital capacity (FVC), and diffuse carbon monoxide (DLCO) (with respective r-values of 0.824, 0.841, and 0.829; all p < 0.001). In contrast, EI and ATI exhibited significantly negative correlations with FEV1, FEV1/FVC, and DLCO (with r-values ranging from -0.837 to -0.885; all p < 0.001).
    The assessment of serum IgA combined with thoracic CT parameters offers valuable insights for diagnosing and evaluating acute exacerbations of COPD, presenting a straightforward clinical utility.
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  • 文章类型: Systematic Review
    AGFAD(ArbeitsgemeinschaftfürForensischeAlterdiagnostik,法医年龄诊断研究小组)发表了有关锁骨内侧骨phy(MCE)的计算机断层扫描(CT)的技术方面以及读取和解释法医年龄估计(FAE)的CT图像的过程的一些建议。有,然而,没有关于CT扫描方案的公开推荐,也没有MCECT的剂量参考值.此分析的目的是评估FAE从业人员对AGFAD建议的依从性,并分析报告的剂量相关CT扫描参数,以帮助建立基于证据的FAE剂量参考值。在PubMed和GoogleScholar中使用特定的MeSH术语进行了系统的文献检索,以识别1997年至2022年有关MCECT的FAE的原始研究文章。共纳入48项研究。在使用Schmeling主要阶段方面,FAE从业者对AGFAD建议的依从性很高(93%),骨窗(79%),≤1mmCT切片(67%),轴向/冠状CT图像(65%),和Kellinghaus子阶段(59%)。CT技术和CT剂量相关扫描参数的报告是不均匀的,并且在当前文献中通常是不完整的。考虑到AGFAD在建立生活受试者的FAE实践标准方面取得的成功,AGFAD也有可能在FAE中建立辐射防护标准。
    The AGFAD (Arbeitsgemeinschaft für Forensische Alterdiagnostik, Study Group on Forensic Age Diagnostics) has published several recommendations regarding both technical aspects of computed tomography (CT) of the medial clavicular epiphysis (MCE) and the process of reading and interpreting the CT images for forensic age estimations (FAE). There are, however, no published recommendations regarding CT scan protocols and no dose reference values for CT of the MCE. The objective of this analysis was to assess adherence to AGFAD recommendations among practitioners of FAE and analyse reported dose-relevant CT scan parameters with the objective of helping to establish evidence-based dose reference values for FAE. A systematic literature search was conducted in PubMed and in Google Scholar with specific MeSH terms to identify original research articles on FAE with CT of the MCE from 1997 to 2022. A total of 48 studies were included. Adherence to AGFAD recommendations among practitioners of FAE is high regarding the use of Schmeling main stages (93%), bone window (79%), ≤ 1 mm CT slices (67%), axial/coronal CT images (65%), and Kellinghaus sub-stages (59%). The reporting of CT technique and CT dose-relevant scan parameters is heterogeneous and often incomplete in the current literature. Considering the success achieved by the AGFAD in creating standards of practice of FAE in living subjects, there is potential for the AGFAD to establish standards for radiation protection in FAE as well.
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  • 文章类型: Journal Article
    The American Association of Physicists in Medicine (AAPM) is a nonprofit professional society whose primary purposes are to advance the science, education and professional practice of medical physics. The AAPM has more than 8000 members and is the principal organization of medical physicists in the United States. The AAPM will periodically define new practice guidelines for medical physics practice to help advance the science of medical physics and to improve the quality of service to patients throughout the United States. Existing medical physics practice guidelines will be reviewed for the purpose of revision or renewal, as appropriate, on their fifth anniversary or sooner. Each medical physics practice guideline represents a policy statement by the AAPM, has undergone a thorough consensus process in which it has been subjected to extensive review, and requires the approval of the Professional Council. The medical physics practice guidelines recognize that the safe and effective use of diagnostic and therapeutic radiology requires specific training, skills, and techniques, as described in each document. Reproduction or modification of the published practice guidelines and technical standards by those entities not providing these services is not authorized. The following terms are used in the AAPM practice guidelines: (a) Must and Must Not: Used to indicate that adherence to the recommendation is considered necessary to conform to this practice guideline. (b) Should and Should Not: Used to indicate a prudent practice to which exceptions may occasionally be made in appropriate circumstances.
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  • 文章类型: Journal Article
    OBJECTIVE: To investigate the impact of computed tomography (CT) image acquisition and reconstruction parameters, including slice thickness, pixel size, and dose, on automatic contouring algorithms.
    METHODS: Eleven scans from patients with head-and-neck cancer were reconstructed with varying slice thicknesses and pixel sizes. CT dose was varied by adding noise using low-dose simulation software. The impact of these imaging parameters on two in-house auto-contouring algorithms, one convolutional neural network (CNN)-based and one multiatlas-based system (MACS) was investigated for 183 reconstructed scans. For each algorithm, auto-contours for organs-at-risk were compared with auto-contours from scans with 3 mm slice thickness, 0.977 mm pixel size, and 100% CT dose using Dice similarity coefficient (DSC), Hausdorff distance (HD), and mean surface distance (MSD).
    RESULTS: Increasing the slice thickness from baseline value of 3 mm gave a progressive reduction in DSC and an increase in HD and MSD on average for all structures. Reducing the CT dose only had a relatively minimal effect on DSC and HD. The rate of change with respect to dose for both auto-contouring methods is approximately 0. Changes in pixel size had a small effect on DSC and HD for CNN-based auto-contouring with differences in DSC being within 0.07. Small structures had larger deviations from the baseline values than large structures for DSC. The relative differences in HD and MSD between the large and small structures were small.
    CONCLUSIONS: Auto-contours can deviate substantially with changes in CT acquisition and reconstruction parameters, especially slice thickness and pixel size. The CNN was less sensitive to changes in pixel size, and dose levels than the MACS. The results contraindicated more restrictive values for the parameters should be used than a typical imaging protocol for head-and-neck.
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  • 文章类型: Journal Article
    目的:本研究旨在根据影响患者剂量和图像质量的CT参数评估计算机断层扫描(CT)临床实践受体的知识和实践。
    方法:向60名CT受体发放了一份自编问卷,调查了参与者的人口统计学信息和CT参数及辐射剂量知识。
    结果:受邀技术人员的响应率为92%。年龄在24至59岁之间的男性38(69%)和女性17(31%),平均年龄为37.8岁.参与者的经验介于2到24年之间,平均15.5年。平均知识得分为72.2%,正确答案范围为9-18,平均值(±SD)为13.1±2.1。参与者对诊断参考水平(DRL)的认识较低。然而,他们表现出良好的整体知识,具有改进的潜力和实践的信心。
    结论:持续的医学教育和专业发展是改进的重点,以确保可靠地提供医疗保健和最佳实践。教育机构和卫生组织在设计教育计划时可以使用这项研究的结果,以确保其技术人员的最高培训和表现。
    OBJECTIVE: This study aimed to assess the knowledge and practice of computed tomography (CT) clinical practice preceptors in terms of CT parameters affecting patient dose and image quality.
    METHODS: A self-administered questionnaire that surveyed the participants\' demographic information and knowledge about CT parameters and radiation doses was distributed to 60 CT preceptors.
    RESULTS: The response rate of the invited technologists was 92 %. 38 (69 %) males and 17 (31 %) females aged between 24 and 59 years, with a mean age of 37.8. The participants\' experience ranged between 2 and 24 years, with a mean of 15.5 years. The average knowledge score was 72.2 %, with a range of correct answers of 9-18 and a mean (±SD) of 13.1 ± 2.1. The participants showed a low awareness of diagnostic reference levels (DRLs). However, they demonstrated good overall knowledge, with a potential for improvement and confidence in practice.
    CONCLUSIONS: Continuous medical education and professional development are a priority for improvement to ensure reliable delivery of health care and best practice. The findings of this study can be used by education institutes and health organizations when designing educational programs to ensure the highest training and performance of their technologists.
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