1.Clinical application of diffusion tensor imaging in acute stroke
Chinese Journal of Radiology 2001;0(07):-
Objective To reveal the transmiting discipline of parameters and define time window for therapy of ischemia penumbra by continuous detection of diffusion tensor imaging(DTI), and evaluate the relations between cortical spinal tracts(CST) and myodynamia by diffusion tensor tract(DTT). Methods 71 patients of cerebral infarction with different timing were imaged with conventional MRI, DWI and DTI, measuring DCavg, FA, RA , 1-VR of different ROI and performing DTT in ten patients. Results DCavg of lesions in different phases were [(0.275?0.022),(0.349?0.019),(0.465?0.023),(0.538?0.035)]?10~ -3mm~2/s, respectively. DCavg value showed tendency of reducing obviously, elevating gradually and false-normalizing (P
2.Study on the application of EPC in management of hospital energy saving
China Medical Equipment 2014;(12):92-94
Objective: Through the analysis of the current situation of energy consumption and the energy management problems that hospital faced, elaborat the high demands of energy management in hospital effective logistics management, the saving mechanism of Energy Performance Contracting (EPC) is proposed. Methods: The process of introducing EPC to China and related concepts are described, and the main mode and implementation processes as well. Results: To explore the feasibility of the integration in energy-saving reformation and the mode of energy runing management what is the core to EPC, tell people what need to pay attention to in the implementation process, and provide scientific methods for energy management of efficiency operation and sustainable development in hospital. Conclusion:At last, pointing out that saving mechanism of EPC is suitable for hospitals and will bring significant saving benefit.
3.Blood oxygenation level dependent effect of cerebral ischemic penumbra in monkey reversible middle cerebral artery occlusion model
Jing ZHANG ; Yingmin CHEN ; Yunting ZHANG
Chinese Journal of Radiology 2010;44(1):90-95
Objective To investigate the value of blood oxygenation level dependent (BOLD) MRI in detecting monkey cerebral ischemic penumbra (IP). Methods Six monkeys were used to make reversible middle cerebral artery occlusion (MCAO) model by an interventional microcatheter method. MR DWI, PWI mean transit time (MTT), T_2WI and quantitative T_2 map, T_2~* map were performed at MCAO (0 h) and 1,3,6,12,24,48 h after reperfusion. Reversible transverse relaxation rate (R_2') BOLD imaging was calculated using quantitative T_2 and T_2~* maps. Lesion volume percentage (lesion volume/bilateral hemispheres volume) were measured on 0 h DWI,48 h T_2WI and TTC staining. Ischemic area was subdivided into infracted core (high signal area on both 0 h DWI and 48 h T_2 WI), IP (high signal on 0 h DWI, iso on 48 h T_2 WI) and oligemia (0 h delayed MTT, iso signal on both 0 h DWI and 48 h T_2 WI). Relative R_2' (rR_2') was calculated to get ratio between the lesion and mirror area in contralateral healthyhemisphere. Paired t test and correlation analysis were used for comparison of lesion volume percentage. rR_2' values at each time point were compared by ANOVA. Results Reversible MCAO models were made successfully in 4 of 6 monkeys. Lesion volume porcentage on 48 h T_2 WI was reduced compared to that on Oh DWI [ (8.16±0.55)% vs (11.37±1.41)% ,t=6.472,P<0.05]. There was no significant difference in lesion volume percentage between TTC staining and 48 h T_2 WI[ (8.15±0.62)% vs (8.16±0.55)%, t= 0.150,P>0.05], which showed significant positive correlation (r=0.98, P<0.05). rR_2' values were significant different at each time point, with highest in ohgemia followed by IP and infarcted core (P< 0.05). rR_2' values in infracted core, IP and oligemia were: 0 h(1.129±0.108,1.329±0.081,1.584± 0.103,F=36.19,P<0.05),1 h(0.668±0.082,1.237±0.072,1.435±0.066,F=134.09,P<0.05), 3 h (0.536±0.075,1.453±0.081,1.770±0.141, F=256.30, P<0.05), 6 h (0.259±0.050,2.435± 0.131,2.957±0.177,F=803.25,P<0.05), 12 h(0.385±0.054,2.447±0.148,3.254±0.184,F= 743.74,P<0.05),24 h(0.083±0.026,1.968±0.127,3.101±0.144,F=1236.26,P<0.05),48 h (0.246±0.058,3.694±0.218,4.297±0.322, F=557.02, P<0.05). After reperfusion, rR_2' values in IP and oligemia showed increased trend with time evolution and reflected positive BOLD effect, while the infracted core showed decreased trend, reflecting negative BOLD effect. Conclusion R_2' BOLD can delineate IP from infracted core according to the difference of oxygen metabolic status in ischemic brain tissue.
4.Experimental study on the pathological basis of high signal intensity on T_1 weighted image after brain ischemia in rats
Yanshuang REN ; Yunting ZHANG ; Songling LIU
Chinese Journal of Radiology 2001;0(08):-
Objective To verify the pathol ogical basis of high signal intensity on T 1 weighted image after brain ischemia by using the rat model. Methods Fifty-six male Wistar rats, weighing 250 to 300 g, were used for the model of middle cerebral artery occlusion(MCAO). 46 rats model were counted in the results. They were divided into two groups randomly, experimental group (T 1, n =39) and control group (T 0, n =7). Experimental group was further divided into 4 subgroups: 15 minute's MCAO (T 1-a, n =13), 30 minute's MCAO (T 1-b, n =12), 60 minute's MCAO (T 1-c, n =7), and permanent MCAO (T 1-d, n =7). Intraluminal filament technique was used with the method modified by Zea-Longa. Follow-up MRI was applied to observe the time and the position of short T 1 signal. H & E staining and electronic microscope were applied to observe the pathological changes in the position of short T 1 signal. Results In T 0 group ( n = 7), no short T 1 signal was observed in bilateral cerebral hemispheres. In T 1-a subgroup ( n =13), short T 1 signal was observed in 7 rats at the 14 th day. In T 1-b subgroup ( n =12), short T 1 signal was observed in the ischemic side in 8 rats. All of the rats in T 1-c subgroup ( n =7) and T 1-d subgroup ( n =7) were observed to have short T 1 signal. The histological changes of short T 1 signal were hemorrhage, lipid-laden macrophage, denatured protein, and myelinolysis. Earlier short T 1 signal in cortical region was mainly related with hemorrhage, short T 1 signal in the basal ganglia appeared at a later stage, which was induced by lipid-laden macrophages. The occurrence of short T 1 signal was prominently different in the time of MCAO (? 2=29.328, P
5.Influence of tube voltage on CT attenuation, radiation dose,and image quality:phantom study
Fengtan LI ; Dong LI ; Yunting ZHANG
Chinese Journal of Radiology 2013;(5):458-461
Objective To assess the influence of tube current and tube voltage on the CT attenuation,radiation dose,and image quality.Methods A total of 113 saline solutions with decreasing dilution of contrast medium (370 mg I/ml) was produced.MDCT scan was performed with 15 series of different settings of tube current and tube voltage.CT attenuations with 15 series of different settings were all measured,and influence of tube current and tube voltage on CT attenuations was analyzed.CT dose index (CTDIvol) was recorded.The CT attenuations with different tube voltage and current were compared with one-way ANOVA and Kruskal-Wallis rank sum test.The correlation of CT attenuation with different tube voltage and the influence of tube voltage and current on radiation dose and image quality were tested by correlation analysis.Results Tube current (250,200,150,100,and 50 mA) had no significant effect on CT attenuation (F =0.001,0.008,0.075,P > 0.05),while tube voltage (120,100,and 80 kV) had significant effect (H =17.906,17.906,13.527,20.124,23.563,P < 0.05).The correlation between CT attenuation and tube voltage was determined with equation:CT attenuatio N100 kV =1.561 × CT attenuatio N120kv + 4.0818,CT attenuatio N80kV =1.2131 × CT attenuatio N120kv + 0.9283.The influence of tube voltage on radiation dose and image quality was also analyzed,and equations were also obtained:N120 kV =-5.9771Ln(D120 kV) + 25.412,N100 kV =--10.544Ln (D100 kV) + 36.262,N80 kV =-25.326Ln(D80kv) +62.816.According to the results of relationship among CT attenuation,radiation dose,and image quality,lower tube voltage with higher tube current can reduce the radiation dose.Conclusions Lower tube voltage can reduce the radiation dose.However,CT attenuation was influenced,and correction should be done with the equations.
6.Tumor angiogenesis in rabbit VX2 brain tumor: model establishment,pathologic study and preliminary imaging observation
Liqing KANG ; Yunting ZHANG ; Shimei SUN
Chinese Journal of Radiology 2001;0(03):-
Objective To establish a stable implanted model of VX2 rabbit brain tumor, and to evaluate the pathological and imaging features and tumor angiogenesis. Methods Thirty New Zealand white rabbits were implanted with 100 ?l viable VX2 tumor cells (107/ml) through a hole 5 mm to the right of the sagittal suture and 5 mm posterior to the coronal suture bored by a dental drill. MRI was performed every ~2 days after 7 days of implantation to evaluate the growth of the tumor, and perfusion CT studies were performed in different days of tumor growth. After that the animals were sacrificed on days 14, 18, 22, 26, and 30 of tumor implantation. 2% Evans blue (2 ml/kg) was given intravenously in 16 of these animals ~1 hour prior to sacrifice to detect the breakdown of the blood-brain barrier (BBB). The specimens of the rabbit brains were examined pathologically and histologically. VEGF and MVD were evaluated in immunohistochemical examination. Results Of the 22 animals included into the study, the tumor grew in 20 animals, which could be seen clearly on MR imaging. Pathologic examination showed characteristics of squamous carcinoma. VEGF was expressed in all tumors with the mean rate of positive cells of (52.51?19.15)% (19.5%-92.9%). Mean MVD was (51.30?14.42)pice piece/microscope (25-81 pice piece/microscope). Using Pearson′s linear correlation analysis, positive correlation was found between tumor growth time and volume (r=0.791, P=0.000), between MVD and tumor growth time (r=0.875, P=0.000), and between MVD and tumor volume (r=0.901, P=0.000), respectively. Spearman′s rank correlation analysis showed positive correlation between VEGF grade and blue stain of the tumor (r_s=0.594, P=0.015). Conclusion A stable model of VX2 rabbit brain tumor has been established with the method of skull drilling. The method was simple and easy to use, with a high tumor growth rate and remarkable angiogenesis. The model is helpful for the pathological and radiological study of tumor angiogenesis.
7.The neuroprotection effects of basic fibroblast growth factor on focal cerebral ischemia in rats and the expression of bax
Zhixin LI ; Nengshu HE ; Yunting ZHANG
Journal of Interventional Radiology 1994;0(03):-
Objective To study the effect of intra arterial thrombolysis in combination with basic fibroblast growth factor (bFGF), and the protecting mechanism of the bFGF. Methods 50 male Wistar rats were subjected to middle cerebral artery occlusion (MACO) for 4 hours by a single fibrin rich clot. The rats were randomly assigned to the following two expremental groups: 1) treatment with urokinase alone; 2) treatment with urokinase and bFGF. The neurological deficits and the volume of lesions on MRI T2WI were observed at different periods after therapy. The expression of bax were analyzed by immunuohistochemical method at each time point. Results Bax expression increased at 3 hours after reperfusion, and reached the peak level at 12h reperfusion. At 6h after therapy, expression of bax ( P
8.Using double inversion recovery sequence for the diagnosis of hippocampal sclerosis at 3.0 T MR
Quan ZHANG ; Yunting ZHANG ; Kailin FENG ; Jing ZHANG ; Quan ZHANG
Chinese Journal of Radiology 2011;45(6):543-546
Objective To investigate the imaging feature of hippocampal sclerosis (HS), and evaluate the diagnostic value of double inversion recovery (DIR) sequence at 3.0 T MR for its diagnosis. Methods Twelve patients with unilateral HS proven by pathology and 12 healthy volunteers were enrolled. All patients received DIR, fluid attenuated inversion recovery (FLAIR) and T2 TSE sequences scans on oblique coronal plane vertical to the hippocampal axis on a 3.0 T MR scanner. Regions of interest (ROI) were set respectively in ipsilateral and contralateral hippocampi hippocampi in patients with HS, and the bilateral hippocampi in healthy volunteneers were placed respectively. Signal to noise ratio (SNR), contrast to noise ratio (CNR), ratio of signal intensity (RSI) and asymmetry index (AI) of each ROI in all hippocampi were calculated and compared among the three sequences. Statistical analysis was performed with one-way ANOVA. Results On DIR images, ipsilateral hippocampal lesions demonstrated extremely high signal intensity. Relative signal intensity of ipsilateral hippocampal lesions, contralateral hippocampi and the hippocampi in control groups healthy volunteneers were 1.50±0.05, 1.26±0.03, 1.18±0.05 (F=172.609,P=0.000), respectively. SNR of ipsilateral hippocampal lesions on DIR, FLAIR and T2 TSE sequences were 84.13±16.62, 50.90±12.38, 63.25±15.46 (F=15.185,P=0.000), respectively. CNR of hippocampus were 13.72±3.73, 6.67±3.02, 7.33±3.65 (F=14.985,P=0.000), respectively.In HS patients, RSI and AI of the ipsilateral hippocampal lesions and contralateral hippocampi among the three sequences did not show statistically significant difference(P=0.078). Conclusions HS manifests extremely high signal intensity on DIR images. On DIR images, the SNR and CNR of HS were higher than those on conventional MR sequences which provide valuable information for the diagnosis of HS.
9.Functional MRI evaluation on activation of premotor area in verb-generation task
Quan ZHANG ; Yunting ZHANG ; Huiming YI ; Wei LI ; Jing ZHANG
Chinese Journal of Medical Imaging Technology 2009;25(10):1769-1772
Objective To evaluate the activation of premotor area (PMA) in verb generation task, and to discuss the possible function of PMA in language expression. Methods Block-designed fMRI with verb generation task was performed on 23 subjects with GE 1.5T MR Scanner. During the test, the subjects were asked to generate a verb based on a given noun word. The white + appeared on the center of the black screen was used as control. The fMRI data were processed with SPM 2. Group analysis was performed with single sample t-test. Average mapping was obtained and overlapped onto standard MNI template. Activation of the PMA was analyzed. Results The fMRI data of eleven subjects were selected for group analysis after head motion effect was ruled out. Average mapping showed activation in the Broca's area, posterior part of the right inferior frontal gyrus, bilateral PMA and supplemental areas (SMA), left posterior parietal cortex, right thalamus, left basal ganglions, right cerebellum, and posterior part of the right temporal lobe. The area with the greatest activated intensity in the brain was the left PMA. Conclusion PMC is important in verb generation and may be responsible for voice processing, motor imagery, word extracting as well as advanced regulation of information.
10.Somatic Sensory Centre of Temporal Lobe:fMRI Study
Zuojun GENG ; Yunting ZHANG ; Quan ZHANG ; Wei LI ; Jing ZHANG
Journal of Practical Radiology 2001;0(08):-
Objective To observe responses of brain evoked by somatic stimuli in healthy subjects with blood oxygenation level-dependent functional magnetic resonance imaging.Methods There were 30 healthy subjects in the study. Block design was used infunctional MR imaging. In experimental tasks somatic stimuli was executed to the hands of every subject at duration 1000 ms,interstimulus intervals 1000 ms.The professional software-SPM99 was performed to process the images.Results For healthy subjects to somatic stimuli, significant activation was observed in bilateral primary and secondary somatic cortex of precentral gyri and postcentral gyri, and temporallobes. Scattered activations could be seen in frontal lobes, supramarginal gyri and hemisphere of cerebella. There was more intensiveactivation in right hemisphere than that in left. There was no significant difference between the activation evoked by somatic stimuli of leftand right extremities. Conclusion somatic stimuli can evoke significant activations in bilateral primary and secondary somatic cortex.Temporal lobes and other brain areas join in the process of somatic stimuli.