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Search Results: 1 - 10 of 32945 matches for " Qiyong Guo "
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Evaluating the Feasibility of an Agglomerative Hierarchy Clustering Algorithm for the Automatic Detection of the Arterial Input Function Using DSC-MRI
Jiandong Yin, Jiawen Yang, Qiyong Guo
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0100308
Abstract: During dynamic susceptibility contrast-magnetic resonance imaging (DSC-MRI), it has been demonstrated that the arterial input function (AIF) can be obtained using fuzzy c-means (FCM) and k-means clustering methods. However, due to the dependence on the initial centers of clusters, both clustering methods have poor reproducibility between the calculation and recalculation steps. To address this problem, the present study developed an alternative clustering technique based on the agglomerative hierarchy (AH) method for AIF determination. The performance of AH method was evaluated using simulated data and clinical data based on comparisons with the two previously demonstrated clustering-based methods in terms of the detection accuracy, calculation reproducibility, and computational complexity. The statistical analysis demonstrated that, at the cost of a significantly longer execution time, AH method obtained AIFs more in line with the expected AIF, and it was perfectly reproducible at different time points. In our opinion, the disadvantage of AH method in terms of the execution time can be alleviated by introducing a professional high-performance workstation. The findings of this study support the feasibility of using AH clustering method for detecting the AIF automatically.
Comparison of K-Means and Fuzzy c-Means Algorithm Performance for Automated Determination of the Arterial Input Function
Jiandong Yin, Hongzan Sun, Jiawen Yang, Qiyong Guo
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0085884
Abstract: The arterial input function (AIF) plays a crucial role in the quantification of cerebral perfusion parameters. The traditional method for AIF detection is based on manual operation, which is time-consuming and subjective. Two automatic methods have been reported that are based on two frequently used clustering algorithms: fuzzy c-means (FCM) and K-means. However, it is still not clear which is better for AIF detection. Hence, we compared the performance of these two clustering methods using both simulated and clinical data. The results demonstrate that K-means analysis can yield more accurate and robust AIF results, although it takes longer to execute than the FCM method. We consider that this longer execution time is trivial relative to the total time required for image manipulation in a PACS setting, and is acceptable if an ideal AIF is obtained. Therefore, the K-means method is preferable to FCM in AIF detection.
Analysis of the geographic distribution of HFRS in Liaoning Province between 2000 and 2005
Hualiang Lin, Qiyong Liu, Junqiao Guo, Jibo Zhang, Jinfeng Wang, Huaxin Chen
BMC Public Health , 2007, DOI: 10.1186/1471-2458-7-207
Abstract: The annual average incidence at the county level was calculated using HFRS cases reported between 2000 and 2005 in Liaoning Province. GIS-based spatial analyses were conducted to detect spatial distribution and clustering of HFRS incidence at the county level, and the difference of relative humidity and forestation between the cluster areas and non-cluster areas was analyzed.Spatial distribution of HFRS cases in Liaoning Province from 2000 to 2005 was mapped at the county level to show crude incidence, excess hazard, and spatial smoothed incidence. Spatial cluster analysis suggested 16 and 41 counties were at increased risk for HFRS (p < 0.01) with the maximum spatial cluster sizes at ≤ 50% and ≤ 30% of the total population, respectively, and the analysis showed relative humidity and forestation in the cluster areas were significantly higher than in other areas.Some clustering of HFRS cases in Liaoning Province may be etiologically linked. There was strong evidence some HFRS cases in Liaoning Province formed clusters, but the mechanism underlying it remains unknown. In this study we found the clustering was consistent with the relative humidity and amount of forestation, and showed data indicating there may be some significant relationships.HFRS is a zoonosis caused by different species of hantavirus (HV) causing fever, hemorrhage, kidney damage and hypotension. HFRS in China has the most severe epidemics having about 90% of the total reported HFRS cases in the world [1-4]. Although some prevention and control measures such as scientific rodent control, vaccination and environment management have been performed, HFRS remains a serious public health problem with about 20,000~50,000 human cases annually in mainland China [5]. And Liaoning Province is one of the most serious affected areas with the most cases in China and the highest incidence during the years 2004 and 2005. The incidence of HFRS shows high variability at the county level. The environmental factors, cl
Molecular phylogenetic relationships of China Seas groupers based on cytochrome b gene fragment sequences
Shaoxiong Ding,Xuan Zhuang,Feng Guo,Jun Wang,Yongquan Su,Qiyong Zhang,Qifu Li
Science China Life Sciences , 2006, DOI: 10.1007/s11427-006-0235-y
Abstract: The classification and evolutionary relationships are important issues in the study of the groupers. Cytochrome b gene fragment of twenty-eight grouper species within six genera of subfamily Epinephelinae was amplified using PCR techniques and the sequences were analyzed to derive the phylogenetic relationships of the groupers from the China Seas. Genetic information indexes, including Kimura-2 parameter genetic distance and T S/T V ratios, were generated by using a variety of biology softwares. With Niphon spinosus, Pagrus major and Pagrus auriga as the designated outgroups, phylogenetic trees, which invoke additional homologous sequences of other Epinephelus fishes from GenBank, were constructed based on the neighbor-joining (NJ), maximum-parsimony (MP), maximum-likelihood (ML) and minimum-evolution (ME) methods. Several conclusions were drawn from the DNA sequences analysis: (1) genus Plectropomus, which was early diverged, is the most primitive group in the subfamily Epinephelinae; (2) genus Variola is more closely related to genus Cephalopolis than the other four genera; (3) genus Cephalopolis is a monophyletic group and more primitive than genus Epinephelus; (4) Promicrops lanceolatus and Cromileptes altivelis should be included in genus Epinephelus; (5) there exist two sister groups in genus Epinephelus.
Right prefrontal laterality of Chinese boys during a Chinese high conflict Stroop task measured by multi-channel near-infrared spectroscopy imaging

Liu Jiacheng,Bai Jing,Peng Miao,Fan Xiaofei,Guo Qiyong,

自然科学进展 , 2007,
Abstract: Some studies have shown that native Chinese speakers have different laterality in matched Stroop tasks from native English speakers. Recently, many imaging data, which show left laterality of English-matched Stroop interference, have been reported. And a few functional imaging studies have been conducted to investigate the phenomenon of the Chinese version of Stroop task. In this study, functional activity in the lateral prefrontal cortex of a group of normal Chinese boys with functional near-infrared imaging during a Stroop color-word task was measured to show different Stroop interferences in the prefrontal cortex. The results show obvious fluctuation of the cerebral blood volume in the right prefrontal cortex in all boys, which agrees with the finding of previous studies, that is, Chinese native boys have right laterality in their brain when the Chinese version of Stroop color-word task is applied.
SOD mRNA and MDA Expression in Rectus Femoris Muscle of Rats with Different Eccentric Exercise Programs and Time Points
Heng Zhao, Jiani Liu, Shinong Pan, Yingwei Sun, Qi Li, Fei Li, Li Ma, Qiyong Guo
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0073634
Abstract: Purpose Although superoxide dismutase (SOD) and malondialdehyde (MDA) affect Delayed Onset Muscle Soreness (DOMS), their effects are unclear in rectus femoris muscles (RFM) of rats with different eccentric exercise programs and time points. The purpose of this study is to investigate the effects of the various eccentric exercise programs at different time points on the SOD mRNA expression and MDA using rat as the animal model. Methods 248 male rats were randomly divided into 4 groups: control group (CTL, n = 8), once-only exercise group (OEG, n = 80), continuous exercise group (CEG, n = 80), and intermittent exercise group (IEG, n = 80). Each exercise group was divided into 10 subgroups that exercised 0.5 h, 6 h, 12 h, 24 h, 48 h, 72 h, 96 h, 120 h, 144 h, or 168 h. Rats were sacrificed and their SOD mRNA expression, and MDA concentrations of skeletal muscle tissue were measured. Results The specimen in all eccentric exercise programs showed increased RFM SOD1 mRNA expression levels at 0.5 h (P<0.05), and decreased RFM SOD3 mRNA expression at 0.5 h (P<0.05). The continuous eccentric exercise (CE) significantly enhanced muscle SOD2 mRNA level at 0.5 h (P<0.05). After once-only eccentric exercise (OE), SOD1, SOD2, and SOD3 mRNA expression significantly increased at 96 h, whereas MDA concentrations decreased at 96 h. After CE, the correlation coefficients of SOD1, SOD2, SOD3 mRNA expression levels and MDA concentrations were ?0.814, ?0.763, ?0.845 (all P<0.05) at 12 h. Conclusion Regular eccentric exercise, especially CE could enhance SOD1 and SOD2 mRNA expression in acute stage and the SOD2 mRNA expression correlates to MDA concentration in vivo, which may improve the oxidative adaption ability of skeletal muscles.
Aberrant Functional Connectivity of Resting State Networks in Transient Ischemic Attack
Rong Li, Shanshan Wang, Ling Zhu, Jian Guo, Ling Zeng, Qiyong Gong, Li He, Huafu Chen
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0071009
Abstract: Background Transient ischemic attack (TIA) is usually defined as a neurologic ischemic disorder without permanent cerebral infarction. Studies have showed that patients with TIA can have lasting cognitive functional impairment. Inherent brain activity in the resting state is spatially organized in a set of specific coherent patterns named resting state networks (RSNs), which epitomize the functional architecture of memory, language, attention, visual, auditory and somato-motor networks. Here, we aimed to detect differences in RSNs between TIA patients and healthy controls (HCs). Methods Twenty one TIA patients suffered an ischemic event and 21 matched HCs were enrolled in the study. All subjects were investigated using cognitive tests, psychiatric tests and functional magnetic resonance imaging (fMRI). Independent component analysis (ICA) was adopted to acquire the eight brain RSNs. Then one-sample t-tests were calculated in each group to gather the spatial maps of each RSNs, followed by second level analysis to investigate statistical differences on RSNs between twenty one TIA patients and 21 controls. Furthermore, a correlation analysis was performed to explore the relationship between functional connectivity (FC) and cognitive and psychiatric scales in TIA group. Results Compared with the controls, TIA patients exhibited both decreased and increased functional connectivity in default mode network (DMN) and self-referential network (SRN), and decreased functional connectivity in dorsal attention network (DAN), central-executive network (CEN), core network (CN), somato-motor network (SMN), visual network (VN) and auditory network (AN). There was no correlation between neuropsychological scores and functional connectivity in regions of RSNs. Conclusions We observed selective impairments of RSN intrinsic FC in TIA patients, whose all eight RSNs had aberrant functional connectivity. These changes indicate that TIA is a disease with widely abnormal brain networks. Our results might put forward a novel way to look into neuro-pathophysiological mechanisms in TIA patients.
Aberrant Whole-Brain Functional Connectivity and Intelligence Structure in Children with Primary Nocturnal Enuresis
Bing Yu, Hongbin Sun, Hongwei Ma, Miao Peng, Fanxing Kong, Fanxing Meng, Na Liu, Qiyong Guo
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0051924
Abstract: Aim To assess the potential relationship between intelligence structure abnormalities and whole-brain functional connectivity in children with primary nocturnal enuresis (PNE) with resting-state functional magnetic resonance imaging (fMRI) to provide insights into the association between these two seemingly unrelated conditions. Methods Intelligence testing and fMRI data were obtained from 133 right-handed children, including 67 PNE children (M/F, 39:28; age, 10.5±1.2 y) and 66 age-matched healthy controls (M/F, 37:29; age, 10.1±1.1 y). All intelligence tests were performed using the China-Wechsler Intelligence Scale for Children (C-WISC). Each subject’s full intelligence quotient (FIQ), verbal IQ (VIQ), performance IQ (PIQ), and memory/caution (M/C) factor was measured and recorded. Resting state fMRI scans were performed on a 3.0-T MR scanner and post-processed using REST software. Comparisons of z-score correlation coefficients between distinct cerebral regions were used to identify altered functional connectivity in PNE children. Results The PNE group had normal FIQ, VIQ, and PIQ values, indicating no significant variation from the control group. However, the M/C factor was significantly lower in the PNE group. Compared to the control group, PNE children exhibited overall lower levels of functional connectivity that were most apparent in the cerebello-thalamo-frontal pathway. The M/C factor significantly correlated with z-scores representing connectivity between Cerebellum_Crus1_L and Frontal_Mid_R. Conclusion PNE children exhibit intelligence structure imbalance and attention deficits. Our findings suggest that cerebello-thalamo-frontal circuit abnormalities are likely to be involved in the onset and progression of attention impairment in PNE children.
Optimizing Radiation Dose Levels in Prospectively Electrocardiogram-Triggered Coronary Computed Tomography Angiography Using Iterative Reconstruction Techniques: A Phantom and Patient Study
Yang Hou, Jiahe Zheng, Yuke Wang, Mei Yu, Mani Vembar, Qiyong Guo
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0056295
Abstract: Aim To investigate the potential of reducing the radiation dose in prospectively electrocardiogram-triggered coronary computed tomography angiography (CCTA) while maintaining diagnostic image quality using an iterative reconstruction technique (IRT). Methods and Materials Prospectively-gated CCTA were first performed on a phantom using 256-slice multi-detector CT scanner at 120 kVp, with the tube output gradually reduced from 210 mAs (Group A) to 125, 105, 84, and 63 mAs (Group B–E). All scans were reconstructed using filtered back projection (FBP) algorithm and five IRT levels (L2-6), image quality (IQ) assessment was performed. Based on the IQ assessment, Group D(120 kVp, 84 mAs) reconstructed with L5 was found to provide IQ comparable to that of Group A with FBP. In the patient study, 21 patients underwent CCTA using 120 kV, 210 mAs with FBP reconstruction (Group 1) followed by 36 patients scanned with 120 kV, 84 mAs with IRT L5 (Group 2). Subjective and objective IQ and effective radiation dose were compared between two groups. Results In the phantom scans, there were no significant differences in image noise, contrast-to-noise ratio (CNR) and modulation transfer function (MTF) curves between Group A and the 84 mAs, 63 mAs groups (Groups D and E). Group D (120 kV, 84 mAs and L5) provided an optimum balance, producing equivalent image quality to Group A, at the lowest possible radiation dose. In the patient study, there were no significant difference in image noise, signal-to-noise ratio (SNR) and CNR between Group 1 and Group 2 (p = 0.71, 0.31, 0.5, respectively). The effective radiation dose in Group 2 was 1.21±0.14 mSv compared to 3.20±0.58 mSv (Group 1), reflecting dose savings of 62.5% (p<0.05). Conclusion iterative reconstruction technique used in prospectively ECG-triggered 256-slice coronary CTA can provide radiation dose reductions of up to 62.5% with acceptable image quality.
The Current Status of Radiology in Neuro-Psychiatric Disorders
Qiyong Gong
Iranian Journal of Radiology , 2009,
Abstract: "n"nThe availability of multimodal imaging techniques enables the acquisition of both structural and functional information of the brain, and it opens a unique window for revealing the brain activity and connectivity in neuro-psychiatric disorders. The current lecture will review some of the most often used imaging modalities, with particular emphasis on MRI, in the research field of major neuro-psychiatric disorders from the functional perspective. Diffused tension image shows the white matter in vivo and provides us with useful parameters such as FA and ADC to assess the brain tissue integrity. Perfusion MRI helps to assess the cerebral blood flow relevant to functional alteration. BOLD fMRI is readily available for the functional brain assessment in psychiatry with task and non-task design (i.e. resting-state fMRI). The topic of fMRI will be focused, and in particular, the resting-state fMRI which has recently attracted considerable attentions and has shown potentials in future clinical applications. The current lecture will specifically focuse on the recent advances of MR imaging research in epilepsy, schizophrenia and major depressive disorders.
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