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        find Keyword "tomography" 374 results
        • Imaging modality-independent anatomy of the left heart: implications for left-sided transcatheter interventions

          Interventional cardiologists have traditionally relied upon fluoroscopic imaging for percutaneous coronary interventions. Transcatheter structural heart interventions, however, require additional imaging modalities such as echocardiography and multislice computed tomography (MSCT) for pre-, intra- and post-procedural assistance. During transcatheter structural heart interventions, interventional cardiologists and non-invasive cardiovascular imagers may use different terminologies to describe a certain structure, thus causing misunderstandings within the team. Herein, we present a modality- independent terminology for understanding volumetric images in the context of transcatheter heart valve therapies. The goal of this system is to allow physicians to readily interpret the orientation of fluoroscopic, MSCT, echocardiographic and MRI images, thus generalising their understanding of cardiac anatomy to all imaging modalities.

          Release date:2018-02-26 05:32 Export PDF Favorites Scan
        • The Role of Monitoring Procalcitonin in Comprehensive Evaluation during Diagnosis and Treatment of Community Acquired Pneumonia

          ObjectiveTo investigate the role of dynamic monitoring procalcitonin (PCT) in the comprehensive evaluation during the diagnosis and treatment of community acquired pneumonia (CAP). MethodsFour hundred and sixty-eight patients with CAP were randomly assigned to a PCT-guided group (the research group) and a standard guideline group (the control group). The clinical symptoms,CURB-65 grade,blood leucocyte count and classification,and C-reactive protein (CRP)were compared between two groups. The PCT-guided application time of antibiotics,the hospitalization time,chest CT examination rate,the cure or the improvement rate were also estimated and commpared. ResultsThe hospitalization time [(9.6±1.7)days vs. (10.9±1.6)days],hospitalization cost [(6 957.11±1 009.46) yuan vs. (8 011.35±1 049.77) yuan],chest CT examination rate (56.96% vs. 89.40%),the application time of antibiotics [(16.5±2.3)days vs. (20.0±1.2)days],and the rate of required antibiotics upgrade (6.96% vs. 11.06%) in the research group were all significantly lower than the control group (P<0.05). There was no significant difference between two groups in the ratio of the adverse reaction of antibiotics (14.78% vs. 15.20%),the rate of transfer into ICU (2.61% vs. 3.69%) or the mortality (1.74% vs. 2.30%)(P>0.05). ConclusionOn the basis of CAP guidelines,the dynamic monitoring of PCT may shorten the time of antibiotic use and the hospitalization,reduce the cost of hospitalization and the rate of chest CT scan in patients with CAP.

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        • Advances in application of optical coherence tomography angiography for quantitative analysis in central serous chorioretinopathy

          Central serous chorioretinopathy (CSC) is one of the representative pachychoroid spectrum disease. Although fundus fluorescein angiography and indocyanine green angiography can be used as the gold standard for the diagnosis of CSC, they are invasive examinations, which may bring certain risks in clinical application and cannot help us obtain quantitative parameters. Optical coherence tomography angiography (OCTA), as a non-invasive and quantitative examination, is an important imaging tool for understanding the pathogenesis, diagnosis and treatment of CSC. With the advancement of OCTA, the swept-source OCTA has a satisfying scanning depth, a wider scanning range and a higher resolution. The development of OCTA broadens the horizons of the pathogenesis of CSC, promotes the understanding of the pathophysiology of CSC, and sheds new light for its clinical diagnosis and treatment. Based on OCTA, the choroid and retina in eyes with CSC are presented with qualitative and quantitative changes in vascular system. OCTA-guided CSC treatment and the discovery of prognostic markers based on OCTA challenge the application of traditional imaging techniques in CSC. With the continuous improvement and progress of OCTA technology, traditional angiography combined with OCTA will bring great benefits to the diagnosis and treatment of CSC. This review summarizes the quantitative application of OCTA in the pathogenesis, diagnosis and treatment of CSC.

          Release date:2023-05-18 10:05 Export PDF Favorites Scan
        • Retinal vascular characteristics in patients with obstructive sleep apnea syndrome assessed by optical coherence tomography angiography: a meta-analysis

          Objective To evaluate the application value of optical coherence tomography angiography (OCTA) in obstructive sleep apnea syndrome (OSAS). Methods A comprehensive search of both domestic and international databases was conducted to identify clinical studies on the use of OCTA in OSAS, from the establishment of the databases to May 2024. A meta-analysis was performed using Revman 5.4 software. Results A total of 134 studies were initially identified, with 14 studies meeting the inclusion criteria, encompassing 999 subjects (739 in the OSAS group and 260 in the healthy group). Meta-analysis results indicated that the superficial capillary plexus (SCP) density in the fovea (MD=–2.05, 95%CI –3.75 to –0.35, P=0.02) and parafovea (MD=–1.56, 95%CI –2.44 to –0.68, P=0.000 5) was significantly lower in the OSAS group compared with the healthy group. In the mild to moderate OSAS group, SCP density was significantly lower in the fovea (MD=–2.41, 95%CI –4.32 to –0.49, P=0.01), parafovea (MD=–1.17, 95%CI –2.01 to –0.32, P=0.007), and perifovea (MD=–1.73, 95%CI –2.69 to –0.77, P=0.000 4) compared with the healthy group. In the severe OSAS group, SCP density in the perifovea (MD=–1.33, 95%CI –2.53 to –0.13, P=0.03) was significantly lower than that of the healthy group. SCP density in the whole area (MD=0.36, 95%CI 0.05 to 0.68, P=0.02) was significantly higher in the mild to moderate OSAS group compared with the severe OSAS group. In the deep capillary plexus (DCP) density, the OSAS group showed significantly lower densities in the whole area (MD=–2.16, 95%CI –3.51 to –0.81, P=0.002), fovea (MD=–2.38, 95%CI –4.38 to –0.37, P=0.02), and parafovea (MD=–2.33, 95%CI –3.93 to –0.73, P=0.004) compared with the healthy group. The mild to moderate OSAS group also showed significantly lower densities in the whole area (MD=–2.02, 95%CI –3.33 to –0.72, P=0.002) and parafovea (MD=–1.65, 95%CI –3.04 to –0.26, P=0.02) compared with the healthy group. The severe OSAS group had significantly lower DCP density in the whole area (MD=–2.26, 95%CI –3.85 to –0.66, P=0.006) and parafovea (MD=–1.47, 95%CI –2.31 to –0.62, P=0.000 7) compared with the healthy group. DCP density in the whole area (MD=0.54, 95%CI 0.02 to 1.07, P=0.04) was significantly higher in the mild to moderate OSAS group compared with the severe OSAS group. Regarding the retinal nerve fiber layer (RNFL) thickness, the inferior quadrant (MD=4.01, 95%CI 0.69 to 7.32, P=0.02) and temporal quadrant (MD=4.35, 95%CI 1.88 to 6.82, P=0.000 6) were significantly thicker in the mild to moderate OSAS group compared with the severe OSAS group. In terms of the foveal avascular zone (FAZ) area, the severe OSAS group showed a significantly larger FAZ area (MD=0.06, 95%CI 0.03 to 0.08, P<0.000 01) compared with the healthy group. Conclusion OCTA-related ocular biomarkers may be associated with the occurrence and progression of OSAS and have potential applications in the diagnosis and treatment of OSAS.

          Release date:2025-03-25 01:25 Export PDF Favorites Scan
        • Differentiation of autoimmune pancreatitis and pancreatic ductal adenocarcinoma based on multi-modality texture features in 18F-FDG PET/CT

          Autoimmune pancreatitis (AIP) is a unique subtype of chronic pancreatitis, which shares many clinical presentations with pancreatic ductal adenocarcinoma (PDA). The misdiagnosis of AIP often leads to unnecessary pancreatic resection. 18F-FDG positron emission tomography/ computed tomography (PET/CT) could provide comprehensive information on the morphology, density, and functional metabolism of the pancreas at the same time. It has been proved to be a promising modality for noninvasive differentiation between AIP and PDA. However, there is a lack of clinical analysis of PET/CT image texture features. Difficulty still remains in differentiating AIP and PDA based on commonly used diagnostic methods. Therefore, this paper studied the differentiation of AIP and PDA based on multi-modality texture features. We utilized multiple feature extraction algorithms to extract the texture features from CT and PET images at first. Then, the Fisher criterion and sequence forward floating selection algorithm (SFFS) combined with support vector machine (SVM) was employed to select the optimal multi-modality feature subset. Finally, the SVM classifier was used to differentiate AIP from PDA. The results prove that texture analysis of lesions helps to achieve accurate differentiation of AIP and PDA.

          Release date:2019-12-17 10:44 Export PDF Favorites Scan
        • Changes of choroidal biomarkers in patients with central serous chorioretinopathy

          Objective To quantitatively evaluate the changes of choroidal biomarkers in patients with central serous chorioretinopathy (CSC) and preliminarily explore its pathogenesis. MethodsClinical cross-sectional study. From July 2021 to December 2022, 74 eyes of 65 patients with CSC (CSC group) confirmed by ophthalmic examination at the First Affiliated Hospital of Zhengzhou University were included in the study. Among them, 46 patients (51 eyes) were male, 19 patients (23 eyes) were female. The duration from the onset of symptoms to the time of treatment was less than or equal to 3 months. A control group consisted of 40 healthy volunteers (74 eyes) matched in age and gender. Among them, 26 patients (50 eyes) were male, and 14 patients (24 eyes) were female. Using VG200D from Microimaging (Henan) Technology Co., Ltd., macular scanning source light coherence tomography angiography was performed, with scanning range 6 mm × 6 mm. According to the division of the diabetes retinopathy treatment research group, the choroid within 6 mm of the macular fovea was divided into three concentric circles centered on the macular fovea, namely, the central area with a diameter of 1 mm, the macular area with a diameter of 1-3 mm, and the surrounding area of the fovea with a diameter of 3-6 mm. The device comes with software to record the three-dimensional choroidal vascular index (CVI), choroidal vascular volume (CVV), perfusion area of the choroidal capillary layer (CFA), choroidal thickness (CT), and three-dimensional CVI, CVV, and CT in the upper, temporal, lower, and subnasal quadrants within 6 mm of the fovea. Quantitative data between the two groups were compared using an independent sample t-test. Qualitative data comparison line χ2 inspection. The value of receiver operating curve (ROC) analysis in predicting the occurrence of CSC, including CVI, CVV, CFA, and CT. ResultsCompared with the control group, the CVI (t=3.133, 4.814), CVV (t=7.504, 9.248), and CT (t=10.557, 10.760) in the central and macular regions of the affected eyes in the CSC group significantly increased, while the CFA (t=-8.206, -5.065) significantly decreased, with statistically significant differences (P<0.05); CVI (t=7.129), CVV (t=10.020), and CT (t=10.488) significantly increased within 6 mm of the central fovea, while CFA (t=-2.548) significantly decreased, with statistically significant differences (P<0.05). The CVI (t=4.980, 4.201, 4.716, 8.491), CVV (t=9.014, 7.156, 7.719, 10.730), and CT (t=10.077, 8.700, 8.960, 11.704) in the upper, temporal, lower, and lower nasal quadrants within 6 mm of the central fovea were significantly increased, with statistically significant differences (P<0.05). In the CSC group, the maximum CVI and CVV were (0.39±0.10)% and (1.09±0.42) mm3, respectively, on the nasal side of the affected eye. Upper CT was (476.02±100.89) μm. The nasal side CVI, CVV, and CT have the largest changes. The ROC curve analysis results showed that the area under the curve of CT, CVV, and CVI within 6 mm of the central region, macular region, and fovea was over than 0.5. Subcentral CT was the most specific for the diagnosis of CSC. ConclusionChoroidal biomarkers CVI, CVV, and CT in CSC patients increase, while CFA decreases. Central CT is the most specific for the diagnosis of CSC.

          Release date:2023-05-18 10:05 Export PDF Favorites Scan
        • Optic coherence tomography for congenital juvenile macular retinoschisis

          ObjectiveTo observe the characteristics of images of optic coherence tomography (OCT) for the macular region of congenital retinoschisis and investigate its significance.MethodsThe data of OCT of 11 patients (20 eyes) with congenital macular retinoschisis diagnosed by direct or preplacedmirror ophthalmoscopy, fundus fluorescein angiography (FFA), and electroretinography (ERG) were retrospectively analyzed.ResultsThe images of OCT showed split in the mid portion of sensory retina at the macula in all eyes. The retina of fovea centralis was divided by the split into two slightly thickening layers. In addition, in a few number of cases, the parafoveal sensory retina which became much thickening with 2 splits, was divided into 3 layers.ConclusionThe characteristic of images of OCT in macular congenital retinoschisis is the split cavity at the middle layer of the retina, and OCT has a high sensitivity in the diagnosis of congenital retinoschisis. (Chin J Ocul Fundus Dis, 2005,21:93-96)

          Release date:2016-09-02 05:52 Export PDF Favorites Scan
        • Gastrointestinal Wall Thickening in Patients with Hepatic Cirrhosis: MSCT Findings and Clinical Implications

          Objective To determine the frequencies and patterns of gastrointestinal wall thickening at muti-slice computed tomography (MSCT) in patients with hepatic cirrhosis. Methods One hundred and nine patients with cirrhosis and 130 patients without cirrhosis for gastrointestinal wall thickening were retrospectively analyzed by the abdominal MSCT scans. The frequencies of wall thickening were determined in the cirrhosis patients and in those without cirrhosis. The segmental distribution, symmetry and enhancement pattern were evaluated in all patients with cirrhosis for gastrointestinal wall thickening. Results Gastrointestinal wall thickening was seen in 72 cases (66%) with cirrhosis patients and in 12 cases (9%) without cirrhosis patients (Plt;0.005). The jejunum and ascending colon were the most common sites of gastrointestinal wall thickening, which was involved in 32 and 31 patients respectively. The scans of 46 (64%) patients with gastrointestinal wall thickening showed multisegmental distribution. Gastrointestinal wall thickening was concentric and homogeneous in all patients with cirrhosis. Conclusion Gastrointestinal wall thickening is common in patients with hepatic cirrhosis. It frequently involves multiple segments. The jejunum and ascending colon are the most common sites of involvement. MSCT plays an invaluable role in diagnostic evaluation of bowel wall thickening in patients with hepatic cirrhosis.

          Release date:2016-09-08 10:57 Export PDF Favorites Scan
        • MEASUREMENT AND ANALYSIS OF GLENOID BONY ANATOMY BY USE OF THREE-DIMENSIONAL COMPUTED TOMOGRAPHY

          Objective To investigate and analyze the three-dimensional anatomic structure of glenoid bone in some Chinese people so as to provide the accurate anatomic data to design the new prosthesis of glenoid bone for Chinese people. Methods A total of 90 volunteers with two healthy shoulders (52 males and 38 females, aging 19-60 years with an average of 39.6 years) were selected. Five parameters were measured by use of three-dimensional computed tomography, volumerendering technique (VRT) and multiplanar reformation (MPR), including the maximum antero-posterior width (MAPW),antero-posterior radius of curvature (APROC), maximum supero-inferior height (MSIH), supero-inferior radius of curvature(SIROC) and version angle (VA) of glenoid. All parameters were measured two times, and the average values were analysed by SPSS13.0. The level of significance was set at P lt; 0.05. Results The average MAPW was (2.51 ± 0.32) cm, the average APROC was (5.50 ± 1.21) cm, the average MSIH was (3.45 ± 0.29) cm, the average SIROC was (3.98 ± 0.55) cm, and the average VA was (— 0.03 ± 4.66)°. There were no significant differences (P gt; 0.05) in MAPW, APROC, MSIH, SIROC and VA between two sides. There were significant differences (P lt; 0.05) in MAPW, MSIH, SIROC and VA, and no significant difference (P gt; 0.05) in APROC between female and male. MAPW was correlated with APROC, MAPW was correlated with MSIH, APROC was correlated with SIROC, and the correlation coefficient was 0.298, 0.495 and 0.262, respectively. Conclusion There are no significant differences in MAPW, APROC, MSIH, SIROC and VA of glenoid between two sides. There are sexual significant differences in MAPW, MSIH, SIROC and VA. The data and its statistical results may serve as guidel ines for the design of the glenoid component.

          Release date:2016-09-01 09:07 Export PDF Favorites Scan
        • Research progress in CT study of lower esophageal varices with liver cirrhosis

          ObjectiveTo summarize the research progress of CT related to esophageal varices of cirrhotic patients complicated with portal hypertension.MethodsRelevant CT literatures of esophageal varices of cirrhotic patients complicated with portal hypertension were collected to make an review,then summarized the research status and progress of CT in the diagnosis and evaluation of lower esophageal varices.ResultCT had a good correlation with endoscopic diagnosis of esophageal varices, and CT was of great value in evaluating the presence, degree, and risk of esophageal varicose veins, especially in predicting the risk of esophageal varicose veins, which could be used as an effective modality to assist endoscopic examination to a certain extent.ConclusionsCT is an important examination method for esophageal varices, which has important value in diagnosis and evaluation. In the future, more further researches can be carried out to provide more strong and accurate support for the diagnosis and treatment of esophageal varices.

          Release date:2019-06-05 04:24 Export PDF Favorites Scan
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