Computed Tomography Imaging Applications Research Articles

APPLICATION OF NEW RETRIEVAL METHODS IN MICROSCOPIC MEDICAL IMAGES AND CT IMAGES

Medical image retrieval is of great significance for forming correct medical judgments during the diagnosis and treatment process. In response to the fact that there are rich types of features in medical images, this paper constructs a multi-feature fusion model and applies it to medical image retrieval. This multi-feature fusion model utilizes three features. Color information is characterized using three different moments, texture information is obtained using the LBP (Local Binary Pattern) operator, and shape information is described using Hu moments. After collecting three features of medical images, they are fused into a similarity measure model through a self-set weight structure for comparison in medical image retrieval. Experiments show that our method has satisfactory image retrieval result for medical images such as endoscopic images and computed tomography (CT) images. Despite the continuous improvement of recall indicators, the proposed method still has high precision.

Synthesis and Properties of Ag‐Au Alloy Nanoparticles with Controlled Composition for Computed Tomography Imaging Applications

AbstractNumerous non‐invasive assays have been developed to support CT imaging, consequently increasing the precision of diagnosis. Although these efforts made a significant contribution to clinical research, there is still more to be done. The goal is to replace conventional contrast agents with more potent ones. In this study, Ag−Au alloy nanoparticles were fabricated by substitution method between the precursor Au3+ and the previously prepared Ag nanoparticles. Effects of Au3+ quantity on the formation and characteristics of Ag−Au alloy nanoparticles were investigated. It showed that Ag−Au nanoalloy with a size of 14.2±1.0 nm, SPR absorption peak at 520 nm, and Ag: Au atomic ratio of approximately 3 : 1 were appropriate for biomedical applications. After phase transfer using poly (maleic anhydride‐alt‐1‐octadecene) (PMAO), the nano Ag−Au solution owned remarkable durability, stability and non‐toxicity Vero healthy cell line at high test concentration. In‐vitro CT imaging demonstrated a good X‐ray adsorption coefficient, and the hounsfield units (HU) was noticeably increased. As a promising CT contrast agent, the X‐ray attenuation of nano Ag−Au solutions correlated linearly with concentrations. These findings led to a potential application in the biomedical field, particularly in computed tomography (CT) imaging diagnosis.

Application of CT and MRI images based on an artificial intelligence algorithm for predicting lymph node metastasis in breast cancer patients: a meta-analysis

BackgroundThis study aimed to comprehensively evaluate the accuracy and effect of computed tomography (CT) and magnetic resonance imaging (MRI) based on artificial intelligence (AI) algorithms for predicting lymph node metastasis in breast cancer patients.MethodsWe systematically searched the PubMed, Embase and Cochrane Library databases for literature from inception to June 2023 using keywords that included ‘artificial intelligence’, ‘CT,’ ‘MRI’, ‘breast cancer’ and ‘lymph nodes’. Studies that met the inclusion criteria were screened and their data were extracted for analysis. The main outcome measures included sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and area under the curve (AUC).ResultsA total of 16 studies were included in the final meta-analysis, covering 4,764 breast cancer patients. Among them, 11 studies used the manual algorithm MRI to calculate breast cancer risk, which had a sensitivity of 0.85 (95% confidence interval [CI] 0.79–0.90; p < 0.001; I2 = 75.3%), specificity of 0.81 (95% CI 0.66–0.83; p < 0.001; I2 = 0%), a positive likelihood ratio of 4.6 (95% CI 4.0–4.8), a negative likelihood ratio of 0.18 (95% CI 0.13–0.26) and a diagnostic odds ratio of 25 (95% CI 17–38). Five studies used manual algorithm CT to calculate breast cancer risk, which had a sensitivity of 0.88 (95% CI 0.79–0.94; p < 0.001; I2 = 87.0%), specificity of 0.80 (95% CI 0.69–0.88; p < 0.001; I2 = 91.8%), a positive likelihood ratio of 4.4 (95% CI 2.7–7.0), a negative likelihood ratio of 0.15 (95% CI 0.08–0.27) and a diagnostic odds ratio of 30 (95% CI 12–72). For MRI and CT, the AUC after study pooling was 0.85 (95% CI 0.82–0.88) and 0.91 (95% CI 0.88–0.93), respectively.ConclusionComputed tomography and MRI images based on an AI algorithm have good diagnostic accuracy in predicting lymph node metastasis in breast cancer patients and have the potential for clinical application.

Application of multi-spectral CT imaging in Crohn's disease: a systematic review.

No quantitative computed tomography (CT) biomarker is actually sufficiently accurate to assess Crohn's disease (CD) lesion activity, with adequate precision to guide clinical decisions. To assess the available literature on the use of iodine concentration (IC), from multi-spectral CT acquisition, as a quantitative parameter able to distinguish healthy from affected bowel and assess CD bowel activity and heterogeneity of activity along the involved segments. A literature search was conducted to identify original research studies published up to February 2022. The inclusion criteria were original research papers (>10 human participants), English language publications, focus on dual-energy CT (DECT) of CD with iodine quantification (IQ) as an outcome measure. The exclusion criteria were animal-only studies, languages other than English, review articles, case reports, correspondence, and study populations <10 patients. Nine studies were included in this review; all of which showed a strong correlation between IC measurements and CD activity markers, such as CD activity index (CDAI), endoscopy findings and simple endoscopic score for Crohn's disease (SES-CD), and routine CT enterography (CTE) signs and histopathologic score. Statistically significant differences in IC were reported between affected bowel segments and healthy ones (higher P value was P < 0.001), normal segments and those with active inflammation (P < 0.0001) as well as between patients with active disease and those in remission (P < 0.001). The mean normalized IC at DECTE could be a reliable tool in assisting radiologists in the diagnosis, classification and grading of CD activity.

Iterative Reconstruction: State-of-the-Art and Future Perspectives.

Image reconstruction processing in computed tomography (CT) has evolved tremendously since its creation, succeeding at optimizing radiation dose while maintaining adequate image quality. Computed tomography vendors have developed and implemented various technical advances, such as automatic noise reduction filters, automatic exposure control, and refined imaging reconstruction algorithms.Focusing on imaging reconstruction, filtered back-projection has represented the standard reconstruction algorithm for over 3 decades, obtaining adequate image quality at standard radiation dose exposures. To overcome filtered back-projection reconstruction flaws in low-dose CT data sets, advanced iterative reconstruction algorithms consisting of either backward projection or both backward and forward projections have been developed, with the goal to enable low-dose CT acquisitions with high image quality. Iterative reconstruction techniques play a key role in routine workflow implementation (eg, screening protocols, vascular and pediatric applications), in quantitative CT imaging applications, and in dose exposure limitation in oncologic patients.Therefore, this review aims to provide an overview of the technical principles and the main clinical application of iterative reconstruction algorithms, focusing on the strengths and weaknesses, in addition to integrating future perspectives in the new era of artificial intelligence.

Application of CT Imaging in Differential Diagnosis and Nursing of Endocrine Tumors.

In order to investigate the value of preoperative X-ray computed tomography (CT) in predicting the pathological grade of pancreatic neuroendocrine tumors. This paper retrospectively analyzed the CT image examination of pancreatic neuroendocrine tumors, the image characteristics of G-NEC detected by CT image, and the detection of GST by spiral CT. In order to clearly diagnose and evaluate the size and scope of the focus, whether there is adjacent tissue invasion, metastasis, and treatment effect, CT, MR, PET-CT, nuclide specific imaging, and other imaging methods are widely used in the medical treatment of pNEN patients. These imaging methods have the advantages of noninvasive, rapid imaging, objective image medium, and strong repeatability. If the pathological grade of pNEN patients can be obtained by imaging examination before operation, it will be of great benefit to the formulation of treatment strategies and the prediction of clinical outcomes. Combining CT image performance with imaging omics characteristics to establish a prediction model that can develop a better auxiliary decision-making tool for clinical practice. Different pathological grades prompt clinicians to provide personalized and accurate medical treatment for patients, and reduce excessive medical treatment or wrong judgment caused by unclear preoperative diagnostic information.

Nanoparticles: Untying the Gordian Knot in Conventional Computed Tomography Imaging

X-ray computed tomography (CT) imaging plays an essential role in disease diagnosis due to its noninvasive, painless mode and superior penetration depth. However, the resolution of the soft tissue ...

QIBA guidance: Computed tomography imaging for COVID-19 quantitative imaging applications

As the COVID-19 pandemic impacts global populations, computed tomography (CT) lung imaging is being used in many countries to help manage patient care as well as to rapidly identify potentially useful quantitative COVID-19 CT imaging biomarkers. Quantitative COVID-19 CT imaging applications, typically based on computer vision modeling and artificial intelligence algorithms, include the potential for better methods to assess COVID-19 extent and severity, assist with differential diagnosis of COVID-19 versus other respiratory conditions, and predict disease trajectory. To help accelerate the development of robust quantitative imaging algorithms and tools, it is critical that CT imaging is obtained following best practices of the quantitative lung CT imaging community. Toward this end, the Radiological Society of North America's (RSNA) Quantitative Imaging Biomarkers Alliance (QIBA) CT Lung Density Profile Committee and CT Small Lung Nodule Profile Committee developed a set of best practices to guide clinical sites using quantitative imaging solutions and to accelerate the international development of quantitative CT algorithms for COVID-19. This guidance document provides quantitative CT lung imaging recommendations for COVID-19 CT imaging, including recommended CT image acquisition settings for contemporary CT scanners. Additional best practice guidance is provided on scientific publication reporting of quantitative CT imaging methods and the importance of contributing COVID-19 CT imaging datasets to open science research databases.

Comparison of computed tomography imaging with traditional autopsy results

The role of computed tomography (CT) images in forensic identification has been widely recognized. Such images can provide an important basis for identification of the cause of death in complicated and difficult cases, including falls from a height, drowning, explosion and gunshot cases, traffic accidents, and sudden death. However, few reports have focused on the application of CT images in cases of death caused by sharp object injuries. Therefore, the CT images and autopsy findings were compared in a case of death caused by sharp object injuries to the chest and abdomen, and the importance of CT images in cases of death from common sharp object injuries is herein discussed.

Application of Quantitative CT Imaging in Rehabilitation Nursing of Cerebral Apoplexy Patients.

Objectives:Electronic computed tomography (CT) is an important imaging method for the diagnosis of cerebral infarction. This paper explores the preventive effects of quantitative CT imaging and early rehabilitation nursing on patients with cerebral apoplexy and shoulder-hand syndrome.Methods:Sixty cerebral apoplexy patients treated were included as control group and given routine care from September 2018 to May 2020. Sixty cerebral apoplexy patients were included as observation group, and early rehabilitation nursing intervention was given based on control group. The incidence of shoulder-hand syndrome and upper limb function were compared between the two groups, to explore the effectiveness of the CT examination in promoting the physical function restoration.Results:The incidence of shoulder-hand syndrome in observation group after three months of intervention was lower than that in control group, and the severity was less than that in control group (P<0.05); The Ashworth score of muscle tension in observation group after three months of intervention was lower than that in control group, and the simplified FMA score of the upper limbs was higher than that in control group.Conclusion:Early rehabilitation nursing intervention after CT examination can prevent the occurrence of cerebral apoplexy and shoulder-hand syndrome and improve upper limb function, which is worthy of promotion.

Application of Computed Tomography Imaging in Diagnosis of Endocrine Nerve of Gastric Cancer and Nursing Intervention Effect

In this article, some parameters and characteristics of computed tomography (CT) images in patients with gastric cancer are analyzed and the application of CT images in the diagnosis of gastric cancer endocrine nerves and the impact of nursing intervention on the quality and mental state of CT images of patients with gastric cancer are discussed. First, all patients were scanned with CT, and the CT values of the normal stomach wall and all lesions at different single-energy levels were recorded separately. Second, the improved back propagation network model was applied to realize the diagnosis of gastric cancer through the analysis of various features of CT images. The effect of nursing intervention on the image quality and mental state of CT imaging of patients with gastric cancer was studied. The results show that the energy spectrum curve of CT images and the improved back propagation network model are helpful for the initial diagnosis and identification of gastric cancer. Nursing intervention has a good influence on the clinical examination, image diagnosis, and psychological state of patients with gastric cancer, and it is easy for patients to undergo image diagnosis and examination according to correct operating procedures.

Advances in Medical Imaging: Aptamer- and Peptide-Targeted MRI and CT Contrast Agents.

Computed tomography (CT) and magnetic resonance imaging (MRI) are among the most well-established modalities in the field of noninvasive medical imaging. Despite being powerful tools, both suffer from a number of limitations and often fall short when it comes to full delineation of pathological tissues. Since its conception, molecular imaging has been commonly utilized to further the understanding of disease progression, as well as monitor treatment efficacy. This has naturally led to the advancement of the field of targeted imaging. Targeted imaging research is currently dominated by ligand-modified contrast media for applications in MRI and CT imaging. Although a plethora of targeting ligands exist, a fine balance between their size and target binding efficiency must be considered. This review will focus on aptamer- and peptide-modified contrast agents, outlining selected formulations developed in recent years while highlighting the advantages offered by these targeting ligands.

Application of CT Imaging in the Diagnosis of Cerebral Hemorrhage and Cerebral Infarction Nerve Damage

This article analyzes computed tomography (CT) angiography and CT perfusion imaging parameters of patients with cerebral hemorrhage and cerebral infarction, and explores its diagnostic value and clinical significance in the diagnosis of cerebral hemorrhage and cerebral infarction. This article selected 52 patients with ischemic cerebrovascular disease who were treated in our neurology department from January 2015 to December 2018. Twenty of these patients had transient ischemic attacks, and 32 had neurologic damage. According to the onset time, patients with cerebral infarction were divided into 12 cases in group A (onset time <6 hours) and 20 cases in group B (onset time >6 hours). CT perfusion imaging was performed within 24 hours after the onset of cerebral hemorrhage. Patients immediately underwent CT perfusion imaging in the cerebral infarction group, and recorded the CT perfusion imaging parameters to analyze the nerve damage. The results showed that among the 20 patients with cerebral hemorrhage, 14 cases had anterior circulation cerebral hemorrhage, and 6 cases had posterior circulation cerebral hemorrhage. No lesions were found on CT and magnetic resonance imaging. CT angiography of 20 patients with cerebral hemorrhage showed that 18 patients had vascular lesions. In the cerebral infarction group, 30 cases developed vascular disease. Studies have confirmed that changes in brain CT perfusion imaging parameters can reflect changes in brain blood perfusion to diagnose nerve damage, and mean transit time and time to peak are the most sensitive during the diagnosis. CT angiography can detect the degree of stenosis and has important clinical value for the etiology of cerebral hemorrhage and cerebral infarction.

Application of CT Imaging in the Analysis of Thigh Muscle Morphology of Athletes

The objective of the paper is to investigate and explore the effects of progressive muscle relaxation training (PMR) on image qualities of computed tomography (CT) coronary angiography and the relief of anxiety and pain of patients, as well as the improvement of sleep qualities of patients. The SPSS 16.0 statistics software was applied to respectively obtain the mean number, the standard deviation, and P value, etc. and analyze the variances of each group; the analysis was statistically significant at P &lt; 0 05. The results of the study showed that CT could clearly indicate the anatomy of the thigh muscles and adjacent organs, and could better distinguish the bone density; however, its partitioning accuracy of the erector spinae was slightly worse. Therefore, it was inferred that morphological parameters such as CT values would provide persuasive data for clinical diagnosis, intervention therapy, and rehabilitation exercises, etc.

Computed tomography, sinograms, and image reconstruction in the classroom

As part of an undergraduate introductory survey course on medical physics, x-ray computed tomography (CT) was used to illustrate fundamental principles and mathematics in imaging science. A qualitative description of sinograms was presented to students through a hands-on activity involving simple classroom materials, then the basics of tomographic image reconstruction were presented. Modern applications of CT imaging, including for the diagnosis and treatment of disease, were used to emphasize the utility of medical physics and medical imaging. A simple, qualitative description of convolution, including a very elementary presentation on Fourier transforms and inverse transforms, was included to offer a basic introduction to some of the mathematical tools used in medical imaging physics. Electronic media and materials for the lesson plan are available upon request.

Dual-Energy CT Monitoring of Cryoablation Zone Growth in the Spinal Column and Bony Pelvis: A Laboratory Study.

To evaluate the use of dual-energy computed tomography (CT) virtual noncalcium imaging (VNCa) to visualize ice ball growth during skeletal cryoablation procedures in the spine and bony pelvis. Cryoablation was performed in the spine and bony pelvis of swine and human cadavers at 5 and 6 locations, respectively. CT scans were acquired every 2 minutes using a dual-source dual-energy scanner. Artifacts were suppressed using iterative metal artifact reduction, and ablation zones in the bones and surrounding tissue were visualized using multiplanar VNCa and mixed kV imaging. For each probe location and time point, ice detectability was determined and the volume of the ice was measured. At each location, ice was visualized within the bone before reaching critical neural and intraabdominal structures. Within bone, the ice ball could not be visualized on mixed kV images, but was seen using VNCa images before reaching the adjacent soft tissue in 7/11 (64%) scenarios. Volume of the smallest ice ball seen in VNCa images was 18% of the final volume after cryoablation compared with 42% for mixed kV (P= .014). This application of dual-energy CT and VNCa imaging to cryoablation monitoring permits earlier ice visualization within the vertebral column and pelvic bones in near real time. Because these scanners and imaging techniques increase in availability in interventional suites, cryoablation of tumors along the spine and pelvic bone potentially could be performed with greater confidence.

Technical Note: Density correction to improve CT number mapping in thoracic deformable image registration.

To improve the accuracy of computed tomography (CT) number mapping inside the lung in deformable image registration with large differences in lung volume for applications in vertical CT imaging and adaptive radiotherapy. The deep inspiration breath hold (DIBH) CT image and the end of exhalation (EE) phase image in four-dimensional CT of 14 thoracic cancer patients were used in this study. Lung volumes were manually delineated. A Demons-based deformable registration was first applied to register the EE CT to the DIBH CT for each patient, and the resulting deformation vector field deformed the EE CT image to the DIBH CT space. Given that the mass of the lung remains the same during respiration, we created a mass-preserving model to correlate lung density variations with volumetric changes, which were characterized by the Jacobian derived from the deformation field. The Jacobian determinant was used to correct the lung CT numbers transferred from the EE CT image. The absolute intensity differences created by subtracting the deformed EE CT from the DIBH CT with and without density correction were compared. The ratio of DIBH CT to EE CT lung volumes was 1.6 on average. The deformable registration registered the lung shape well, but the appearance of voxel intensities inside the lung was different, demonstrating the need for density correction. Without density correction, the mean and standard deviation of the absolute intensity difference between the deformed EE CT and the DIBH CT inside the lung were 54.5±45.5 for all cases. After density correction, these numbers decreased to 18.1±34.9, demonstrating greater accuracy. The cumulative histogram of the intensity difference also showed that density correction improved CT number mapping greatly. Density correction improves CT number mapping inside the lung in deformable image registration for difficult cases with large lung volume differences.

CCD and scientific-CMOS detectors for submicron laboratory based X-ray Computed tomography

The key component of any CT (X-ray computed tomography) machine is a detection system. In area of scientific CT imaging applications three types of sensors are mainly used. These are amorphous silicon (α-Si) flat panels, complementary metal–oxide–semiconductor (CMOS) and charge-coupled device (CCD) sensors. Here the performance and comparison study of the two lastly named sensor types is conducted in field of high resolution CT imaging. CCD and novel sCMOS-based (scientific CMOS) detection systems are tested using high-resolution laboratory-based Rigaku nano3DX system (ability to achieve submicron voxel resolution). Properties of each camera were evaluated as well as the quality and noise properties of acquired data (both projection and CT data).

Guided Image Filtering Based Limited-Angle CT Reconstruction Algorithm Using Wavelet Frame

Computed tomography (CT) has its irreplaceable function in nondestructive testing and medical diagnosis. In some practical CT imaging applications, the limited-angle scanning is common due to X-ray’s potential harm to human and the limitation of the scanning conditions. Under these circumstances, analytic reconstruction algorithms, like filtered backprojection (FBP), will not obtain satisfactory results because of lacking the projection data. Iterative reconstruction (IR) methods that can incorporate prior knowledge have attracted attention in many fields, and wavelet frame-based regularization reconstruction algorithms have proven to be a useful means to reduce slope artifacts and noise for limited-angle CT. However, with the obtained projection data of the scanned object further reduces, the edge structures and the details of the reconstructed image worsen. For the sake of improving the quality of the reconstructed image from the limited-angle projection data, a guided image filtering (GIF)-based limited-angle CT reconstruction algorithm using wavelet frame was proposed. In each iteration of the proposed algorithm, the reconstructed result constrained by the wavelet frame was used as the guidance image to transfer the important features it contains to the reconstructed result of SART method by GIF. Furthermore, some simulated experiments and real data tests were conducted to evaluate the feasibility and validity of the proposed algorithm, and the qualitative and quantitative indexes indicated that the proposed algorithm was superior to other iterative reconstruction algorithms in artifacts reduction, noise suppression, and structure preservation.

Oxygen Production of Modified Core-Shell CuO@ZrO2 Nanocomposites by Microwave Radiation to Alleviate Cancer Hypoxia for Enhanced Chemo-Microwave Thermal Therapy.

There are acknowledged risks of metastasis of cancer cells and obstructing cancer treatment from hypoxia. In this work, we design a multifunctional nanocomposite for treating hypoxia based on the oxygen release capability of CuO triggered by microwave (MW). Core-shell CuO@ZrO2 nanocomposites are prepared by confining CuO nanoparticles within the cavities of mesoporous ZrO2 hollow nanospheres. 1-Butyl-3-methylimidazolium hexafluorophosphate (IL) is loaded to the CuO@ZrO2 nanocomposites for improving microwave thermal therapy (MWTT). 1-Tetradecanol (PCM) is introduced to regulate the release of chemotherapeutic drugs of doxorubicin (DOX). Thus, the IL-DOX-PCM-CuO@ZrO2 multifunctional (IDPC@Zr) nanocomposites are obtained. Finally, IDPC@Zr nanocomposites are modified by monomethoxy polyethylene glycol sulfhydryl (mPEG-SH, 5 kDa) (IDPC@Zr-PEG nanocomposites). IDPC@Zr-PEG nanocomposites can produce oxygen in the tumor microenvironment during the course of tumor treatment, thereby alleviating the hypoxic state and improving the therapeutic effect. In vivo antitumor experiments demonstrate a very high tumor inhibition rate of 92.14%. In addition, computed tomography (CT) imaging contrast of the nanocomposites can be enhanced due to the high atomic number of Zr. Therefore, IDPC@Zr-PEG nanocomposites can be applied for monitoring the tumor-treatment process in real time. This combined therapy offers many opportunities, such as the production of oxygen from CuO nanoparticles by MW to alleviate hypoxia, the enhancement of combined treatment of MWTT and chemotherapy, and the potential application of CT imaging to visualize the treatment process, which therefore provides a promising method for the clinical treatment of tumors in the future.