Objective To intruduce a method of making cerebral perfusion mapping and measurement using dynamic CT with a personal computer. Methods We generated the cerebral perfusion mapping and measurement from a series dynamic CT images with a personal computer. The theoretic basis of our technique is central volume principle. The application software was made using visual C++ language with Windows 98 platform. Results This method was applied to a case of transient ischemic attack (TIA). The cerebral perfusion mapping contributed to display the abnormal area of ischemia, which showed as normal imaging appearances in routine CT and MR images. Conclusion Personal computer aided mapping and measurement of cerebral perfusion with dynamic CT is a simple and accessible technique for delineating the hemodynamic response, including abnormal regional cerebral blood flow, blood volume, mean transit time, and time to peak in cases of hyperacute ischemic stroke which was viewed as normal imaging findings in routine CT and MR examination. This method is more suitable to examine emergency cases than MR perfusion imaging and may be used in any facility where CT scanner and personal computer are available.

Objective To investigate the applicative value in stages of pre-infarction period using dynamic perfusion CT. Methods Dynamic perfusion CT was performed in 32 cases of cerebral hypoperfusion. The ratios of side-to-side were measured at hypoperfusion areas in the regional cerebral ischemia. The stages of pre-infarction period were made as the following: (Ⅰ 1) TTP was delayed, MTT, rCBF and rCBV were normal; (Ⅰ 2) TTP and MTT were delayed, rCBF was normal, and rCBV was normal or slightly increased; (Ⅱ 1) TTP and MTT were delayed, rCBF was decreased, and rCBV was normal or slightly decreased; (Ⅱ 2) TTP and MTT were delayed, rCBF and rCBV were decreased. Results There were 4 cases in stage Ⅰ 1. Regional hypoperfusion was revealed only by TTP map. The mean ratios of rCBF, rCBV, MTT, and TTP were 1.00, 1.00, 1.00, and 1.30, respectively. In stage Ⅰ 2, the areas of delayed TTP and MTT were found in all 13 cases. The rCBF and rCBV maps appeared normal in 8 cases. Another 5 cases showed normal rCBF and slightly increased rCBV areas. The mean ratios of rCBF, rCBV, MTT, and TTP were 1.00, 1.03, 1.38, and 1.30, respectively. In stage Ⅱ 1, the areas of delayed TTP and MTT were revealed in all 8 cases. The depiction of decreased rCBF was also found in 8 cases. The areas of decreased rCBV were showed in 5 cases, and normal rCBV maps were revealed in 3. The mean ratios of rCBF, rCBV, MTT, and TTP were 0.56, 0.94, 1.49, and 1.47, respectively. In stage Ⅱ 2, the areas of delayed TTP and MTT were revealed in all 4 cases, in whom depiction of decreased rCBF and rCBV was also found. The mean ratios of rCBF, rCBV, MTT, and TTP were 0.42, 0.59, 1.57, and 1.55, respectively. Conclusion CT perfusion imaging and its parameters' analysis may play an increasing role to delineate the depiction of cerebral hypoperfusion in pre-infarction period. Analyzing the relationship of rCBF, rCBV, MTT, and TTP is very helpful to know the status of the capillary vessels in regional cerebral hypoperfusion area and to provide functional information with our stages of pre-infarction period.

To understand the status of the knowledge and skills of the medical staff by using the questionnaire,the authors analyzed the differences and inadequate ness of the first-aid knowledge and skills among the hospital's new recruits to explore how to carry out a targeted first-aid knowledge and skills training.

Objective 　To evaluate the clinical measurement of cerebral perfusion by dynamic CT. Methods　 Thirteen normal adults were examined by dynamic CT for the measurement of cerebral blood flow (CBF). Another dynamic CT scans with the measurement of CBF were performed separately to rule out cerebral ischemia in 5 cases and secondary Parkinson disease in 2. Results　 Normal cerebral cortical perfusion was measured at 59.3～96.8 ml*min-1*100g-1 with the　mean value 76.2 ml*min-1*100g-1. Normal white matter perfusion was measured at 27.1～43.1 ml*min-1*100g-1 with the mean value 33.9 ml*min-1*100g-1. In 5 cases of suspending cerebral ischemia, one showed increase of CBF and 4 presented decrease of CBF. In 2 cases of suspending secondary Parkinson disease, one appeared decrease of CBF and other one was normal. Conclusion　 Dynamic CT scan with the measurement of CBF can demonstrate the hemodynamic status of normal brain and pathological lesion. Combined with routine CT scan, measurement of cerebral perfusion by dynamic CT is an ideal method to show the morphological and functional changes of brain tissue simultaneously.

Objective To investigate variation in the carotid bifurcation geometry of adults of different age by MR angiography images combining image post-processing technique. Methods Images of the carotid bifurcations of 27 young adults (≤40 years old) and 30 older subjects ( >40 years old) were acquired via contrast-enhanced MR angiography. Three dimensional (3D) geometries of the bifurcations were reconstructed and geometric parameters were measured by post-processing technique. Results The geometric parameters of the young versus older groups were as follows: bifurcation angle (70.268°± 16.050° versus 58.857°±13.294°), ICA angle (36.893°±11.837° versus 30.275°± 9.533°), ICA planarity (6.453°±5.009° versus 6.263°±4.250°),CCA tortuosity (0.023°0.011 versus 0.014± 0.005), ICA tortuosity (0.070±0.042 versus 0.046±0.022), ICA/CCA diameter ratio (0.693± 0.132 versus 0.728±0.106), ECA/CCA diameter ratio (0.750±0.123 versus 0.809±0.122), ECA/ ICA diameter ratio (1.103±0.201 versus 1.127±0.195), bifurcation area ratio (1.057±0.281 versus 1.291±0.252). There was significant statistical difference between young group and older group in bifurcation angle, ICA angle, CCA tortuosity, ICA tortuosity, ECA/CCA and bifurcation area ratio (F= 17.16,11.74,23.02,13.38,6.54,22.80,respectively, P<0.05). Conclusions MR angiography images combined with image post-processing technique can reconstruct 3D carotid bifurcation geometry and measure the geometric parameters of carotid bifurcation in vivo individually. It provides a new and convenient method to investigate the relationship of vascular geometry and flow condition with atherosclerotic pathological changes.

Objective To apply a non-invasive and feasible method for the quantification of local wall shear stress (WSS) in vivo using magnetic resonance imaging. Methods The fight common carotid artery of a young healthy male volunteer was examined using cine phase-contrast MR sequence. The cross- sectional area, average flow velocity, maximum velocity and flow rate were obtained. Three dimensional paraboloid model was applied to measure WSS value at common carotid artery. Results The mean/peak WSS was (0.75±0.41)N/m2 for the common carotid artery; The mean (range) velocity was (23.4± 12.0) cm/s; The mean (range) luminal vessel area was (32.2±2.9) mm2; The blood flow rate was (7.8±4. 6) ml/s; Conclusion WSS's magnitude, distribution and changes can be determined by MR imaging combining with the three-dimensional paraboloid method.

Objective To evaluate the role of diffusion weighted (DW) echo planar MRI in differentiating between brain abscesses and necrotic or cystic tumors. Methods Five patients with brain abscesses, 7 with malignant gliomas, and 1 with brain metastasis were consecutively examined using conventional MRI and diffusion weighted imaging (DWI). The apparent diffusion coefficient (ADC) of ROI was measured with two different b values (0 and 1 000 s/mm 2 or 0 and 1 200 s/mm 2). The results were analyzed using two independent samples test. Results On diffusion weighted imaging, brain abscesses showed marked hyperintensity in all 5 patients, whereas necrotic or cystic brain tumors demonstrated hypointensity in all 8 patients. ADC mean values of brain abscesses, which was 0.43?10 -3 cm 2/s, were lower than those of necrotic or cystic portion of brain tumors ( T =15.00, P

Objective To compare the therapeutic effects in respect of ventilatory response and the change of hemodynamics of two modes of mechanical ventilation [ proportional assist ventilation (PAV) vs.Bi-level positive airway pressure ventilation (BiPAP) ] on patients with acute cardiogenic pulmonary edema (ACPE).Methods Thirty-two patients diagnosed as ACPE were recruited from May 2008 to April 2009.After conventional therapy ( cardiotonic,diuretic,vasodilators,oxygen) were ineffective for half an hour,32 patients were randomly divided into three groups:control group ( 12 cases kept conventional treatment without mechanical ventilation),BiPAP group ( 12 cases were treated with BiPAP mode of non-invasive mechanical ventilation plus conventional treatment) and PAV group (8 cases were treated with PAV mode of non-invasive mechanical ventilation along with conventional treatment ).Results PaO2,RR and oxygenation index were improved significantly in three groups after 1 hour treatment ( P ＜ 0.05 ).While PaO2 and oxygenation index in noninvasive ventilation groups were higher than those in control group ( P ＜0.05 ).The time required for amelioration of dyspnea in noninvsaive ventilation groups was shorter than that in control group ( P ＜ 0.05 ).The peak airway pressure and the index of degree of comfort ( VAS score,auxiliary respiratory muscles score) in PAV group were lower than those in BiPAP group (P ＜ 0.05 ).Conclusions Both modes of noninvasive mechanical ventilations could improve the oxygenation and relief of dyspnea in patients with ACPE.PAV and BiPAP had the similar effect in patients with ACPE.The synchronization and comfort in PAV group were better than those in BiPAP group.The PAV mode of noninvasive mechanical ventilation was well accepted by patients with ACPE.

Objective To investigate the visualization and quantitation of hemodynamic variables at carotid artery bifurcation in vivo by combining computational fluid dynamics(CFD)and vascular imaging. Methods A healthy volunteer underwent CT angiography of left carotid artery by SIEMENS multi-slice CT. Parameters of hemodynamics at this carotid bifurcation were calculated and visualized by combining vascular imaging post-processing and CFD.Results (1) The average range of flow velocity was 0.04～0.36 m/s. A region of high velocity was seen at medial wall of internal carotid artery (ICA) and medial wall of external carotid artery (ECA), respectively. The largest contiguous region of low velocity occurred at the carotid bulb. (2)The average range of absolute pressure, static pressure and dynamic pressure was 100 266.70～101 615.90 Pa, -1058.34～290.88 Pa, and 6.12～553.25 Pa, respectively. (3) The average range of wall shear stress (WSS) at the bifurcation was 0.59～5.35 Pa. There was a large region of low WSS at carotid bulb and posterior wall of ICA, with the lowest value of 0.25 Pa. Also there was a small region of low WSS at anterior and lateral wall of ECA.Conclusion CFD combined with vascular imaging can calculate and visualize the parameters of hemodynamics at carotid bifurcation in vivo individually. It is an interdisciplinary science of computer, radiology and hemodynamics and provides a new method to investigate the relationship of vascular geometry and flow condition with atherosclerotic pathological changes.

Objective To investigate the role of micro-RNAs (miR-101 and miR-125a-5p) in autophagy of lipopolysaccharide (LPS) derived human THP-1 macrophages.Methods Human monocytic leukemia cell line THP-1 was cultured in vitro,and it was differentiated into macrophages after being induced with phorbol (50 μg/L) for 48 hours.THP-1 macrophages were stimulated with LPS in 0,250,500,1 000 μg/L respectively for 12 hours,miR-mimic was transfected into THP-1 macrophages as induced by Lipofectamine RNAiMAX,and the transfection efficiency of miRNA was determined with fluorescence microscopy.Enzyme linked immunosorbent assay (ELISA) was used to determine the levels of tumor necrosis factor-α (TNF-α) and monocyte chemotaxis protein-1 (MCP-1) in the supernatants of culture.Western Blot was used to detect the protein expressions of autophagy proteins ATG4D,Beclin1,and LC3 Ⅱ.The expression levels of miR-101 and miR-125a-5p were determined by quantitative reverse transcription-quantitative polymerase chain reaction (RT-qPCR).Results ① The releasing levels of TNF-α and MCP-1 induced by LPS with 250,500,1 000 μg/L were significantly increased as compared the cells without LPS stimulation [TNF-α (ng/L):1 336.1 ± 18.5,1 340.6±24.8,1 364.5± 14.9 vs.47.6±4.4;MCP-1 (ng/L):996.3 ±51.3,934.6±84.3,974.2±69.5 vs.21.3±6.5,all P ＜ 0.01],but no significant differences were found among the three LPS stimulation groups.The protein expressions of ATG4D,Beclin1 and LC3 1Ⅱ were up-regulated in the presence of different LPS concentrations (0,250,500,1 000 μg/L) for 12 hours in THP-1 macrophages (when compared with the cells without LPS stimulation,t value of ATG4D was 8.103,38.410,52.020,P value was 0.015,0.001,＜ 0.001;t value of Beclin1 was 3.026,5.328,3.482,P value was 0.047,0.034,0.037;t value of LC3 Ⅱ was 3.836,6.200,4.665,P value was 0.018,0.003,0.010),and the optimal concentration was 500 tg/L LPS.When THP-1 macrophages were stimulated with 500 μg/L LPS for 12 hours,the expression levels of miR-101 and miR-125a-5p were down-regulated significantly as compared with the cells without LPS stimulation [miR-101 (2-△ △Ct):0.68 ± 0.08 vs.1.95 ±0.26,t =8.047,P =0.001;miR-125a-5p (2-△ △Ct):0.23 ± 0.06 vs.1.69± 0.42,t =5.975,P =0.004].② The higher transfection efficiency was showed under fluorescence microscope.Westem Blot results showed the protein expressions of ATG4D,Beclin1 and LC3 Ⅱ were down-regulated as induced by an over-expression of miR-101 or miR-125a-5p in THP-1 macrophages,and more obviously down regulated by co-transfected with miR-101 and miR-125a-5p (compared with negative control group,t value was 14.550,5.855,14.180,P value was 0.005,0.014,＜ 0.001).Conclusion miR-101 and miR-125a-5p can inhibit the autophagy in LPS challenged THP-1 macrophages,and the potential mechanism might be related to target regulation of ATG4D.