Objective To explore visible properties of T lymphocyte activation in human umbilical cord blood.Methods T lymphocytes of human umbilical cord blood were cultured in RPMI 1640 complete medium and divided into two groups: the experimental group activated with CD3 McAb(10mg/L)plus PHA and the control group cultured without these reagents. Afcer the cell viability being measured, T cell activation was observed with inverted microscope. And then ultrathin section of the cells sample was prepared tobe observed with transmission electron microscope(TEM).Results Morphologically, activated T cells were obviously bigger, their nuclei clear, and most of divided cells had irregular outline;there were cell colonies to be seen in growing regions. Under TEM, there were more vacuoles (visible property of structure) in typically activated T lymphocytes , chromatic agglutination and nucleoli to be observed.Conclusion Main properties of T cell activation of human umbilical cord blood were chromatic agglutination, more vacuoles in cytoplasm and cell colonies formation.

Objective To evaluate the image deformation and measurement error of rotational DSA by model experiment. Methods Five steel balls (diameter: 20 mm) were placed in a horizontal space of 30 mm, the middle of which was as the isocenter for rotational DSA acquisition. Another 5 steel balls (diameter: 10 mm) were placed in a vertical space of 30 mm with the same alignment for rotational DSA acquisition. The screen was divided into five regions and the morphological changes of the ball image were observed at each rotation angle. The experimental images of the left anterior oblique ball images at 20°, 40°and 60° among each two groups were selected and measured by automatic isocenter calibration and sphere calibration respectively, and compared with the actual diameters of balls to calculate the image magnification. Results Except the center one, other balls were of deformation at different rotation angles due to the distance to the detector leading to enlargement and reduction. With automatic isocenter calibration, only the diameter of the center ball corresponded with the actual one, the distance away from the center or the rotation angle was inversely proportional to measurement error (maximum magnification 12.42%).With sphere calibration, the measurement results in various regions at different rotation angle were basically the same, with smaller measurement error (maximum magnification 3.41%). Conclusion Placing the organ of interest in the center area can reduce image distortion in rotational DSA imaging. Selecting reasonable measuring technology according to the lesion location is helpful to control measurement errors.

Objective To study the difference of image quality which based on different reconstruction in head dual‐energy computed tomography angiography (DECTA) scanning ,and evaluate the radiation dose which using different tube voltage in DEC‐TA .Methods An anthropomorphic head phantom with simulated arteries was used for DECTA scanning by different scan parame‐ters (tube voltage 80/140 kV and tube voltage 100/140 kV) ,the data was reconstructed with filtered back projection (FBP) and Si‐nogram Affirmed Iterative Reconstruction (SAFIRE) .The CT values with SD were measured and calculate to SNR and CNR ,the dose length product (DLP) was recorded and invert to effective dose .The image quality and radiation dose were evaluated in differ‐ent imaging condition .Results The image noise of SAFIRE reconstruction was lower than FBP reconstruction in same san parame‐ters .The increase of tube current‐time product from 100 mAs to 300 mAs ,it shows the characteristics of linear tendency .When it was on 260 mAs ,the image quality become stable .The difference between the two groups(80/140 kV ,100/140 kV)of SD of CT value by SAFIRE was significant (P< 0 .05) ,the difference of SNR and CNR between the two groups was not significant (P>0 .05) .The effective doses of group A (80/140 kV) was significantly lower than group B(100/140 kV) .Conclusion Using tube voltage of 80/140 kV combine with SAFIRE algorithm in head DECTA can ensure the image quality ,which can significantly reduce radiation dose .

Objective Using the Chinese anthropomorphic chest phantom to measure the absorbed dose of various tissues and organs under different noise index, and to assess the radiation dose of MSCT chest scanning with the effective dose(ED). Methods The equivalence of the Chinese anthropomorphic chest phantom(CDP-1C) and the adult chest on CT sectional anatomy and X-ray attenuation was demonstrated. The absorbed doses of various tissues and organs under different noise index were measured by laying thermoluminescent dosimeters(TLD) inside the phantom, and the corresponding dose-length products(DLP) were recorded. Both of them were later converted into ED and comparison was conducted to analyze the dose levels of chest CT scanning with automatic tube current modulation (ATCM) under different noise index. Student t-test was applied using SPSS 12.0 statistical software. Results The Phantom was similar to the human body on CT sectional anatomy. The average CT value of phantom are -788.04 HU in lung,45.64 HU in heart,65.84 HU in liver,254.32 HU in spine and the deviations are 0.10%,3.04%, 4.49% and 4.36% respectively compared to humans. The difference of average CT value of liver was statistically significant(t=-8.705,P＜0.05),while the differences of average CT values of lung, heart and spine were not significant(t value were -0.752,-1.219,-1.138,respectively and P＞0.05).As the noise index increased from 8.5 to 22.5, the DLP decreased from 393.57 mGy·cm to 78.75 mGy·cm and the organs dose declined. For example, the average absorbed dose decreased from 22.38 mGy to 3.66 mGy in lung. Compared to ED calculating by absorbed dose, the ED calculating by DLP was lower. The ED values of the two methods were 6.69 mSv and 8.77 mSv when the noise index was set at 8.5. Conclusions Application of the Chinese anthropomorphic chest phantom to carry out CT dose assessment is more accurate. The noise index should be set more than 8.5 during the chest CT scanning based on ATCM technique.

ObjectiveTo compare detection rate of pulmonary nodules and the radiation doses of digital tomosynthesis (DTS) and MSCT chest scanning by using the anthropomorphic chest phantom which containsthermoluminescent dosimeters( TLD ) and simulated pulmonary nodules.Methods The radiation doses of DTS and MSCT scanning were measured by using the anthropomorphic chest phantom which contains 45 TLD and simulated pulmonary nodules.The radiation doses of najor organs were converted into effective dose ( ED ). Three radiologists of different clinical experiences independently reviewed and recorded the density,diameter and position of pulmonary nodules.The sensitivity of nodule detection by DTS and MSCT were compared by Fisher exact test and Chi-square test. The paired t test was conducted to analyze the dose levels of DTS and MSCT.ResultsThe sensitivity of detection nodule by DTS and MSCT were 66.7％ (30/45) and 91.1％ (41/45) respectively.Statistically significant difference between the two examinations existed ( x2 =8.073,P ＜ 0.05).The sensitivity of detection - 650 HU ground glass opacity pulmonary nodule by MSCT and DTS were 93.3％ (14/15) and 73.3％ (11/15) respectively.There was no significant difference between DTS and MSCT ( P ＞ 0.05 ).The sensitivity of detection - 800 HU ground glass opacity nodule and ground glass opacity nodule (d ＜ 8 mm) by DTS were 33.3％ (5/15) and 16.7％ (2/12) respectively,which were lower than those by CT[80.0％ (12/15) and 66.7％ (8/12)].The radiation doses of DTS for various organs in the chest were lower than those of CT. Statistical significant difference between DTS and MSCT existed ( lung t =19.69,thoracic vertebral t =30.01,heart t =16.33,liver t =5.06,breast t =9.43,thyroid gland t =8.05 ;P ＜ 0.05).The effective doses of the DTS and MSCT were 0.65 and 7.71 mSv respectively.ConclusionsThere is no difference between the DTS and MSCT in the detection rate of -650 HU ground glass opacity nodule.For detecting the ground glass opacity nodule ( - 800 HU) and ground glass opacity nodule (d ＜ 8 mm),MSCT is superior to DTS. However,the radiation dosage of DTS is 8.41％ of the MSCT scanning.

Objective To analyze the distribution of image noise in low-dose chest CT scan and optimize the relative scanning parameters.Methods The CT images of the Chinese anthropomorphic chest phantom( CDP-1 C) were simulated into six groups of low-dose images with different noise indexs by using an image noise addition tool.The difference between the preset noise index and analog noise value was compared.The CT images of 20 volunteers were also simulated into nine groups of low dose scans with the tube currents of 10,30,50,80,100,120,150,180 and 240 mA.The noise values of images were recorded and analyzed.Results There was no statistical difference between the analog noise value and the noise index.The image noise of low-dose chest scan was increased with the decrease of tube current.The noise was increased quickly when the current was decreased from 50 to 30 mA ( F =24.09 - 40.79,P ＜ 0.05),but the noise increased slowly when the current decreased from 240 to 80 mA.There was no statistical difference between the noise of 80 mA group and that of 120 mA(P ＞ 0.05).Conclusions The noise addition tool can be used to evaluate the image noise of low-dose chest CT scan.Adoption of 80 mA in chest CT scan would result in low radiation dose without adding image noise.

Objective To evaluate the accuracy and efficiency of the Monte Carlo software in measuring the radiation dose to the patients who received the CCTA (Coronary Computed Tomography Angiography) examination.Methods A anthropomorphic chest phantom underwent CCTA using three scan parameters (tube voltage 80 kV,100 kV and 120 kV).Computer Software ImpactDose 2.0 was used to compute the chest organ dose on the basis of the three groups tube voltage CT scan characteristic,and the stimulation results of ImpactDose 2.0 software was verified by use of anthropomorphic phantom thermoluminescence dosimeter experiment method.Results For all the measured organs except for lung,the absorbed organ dose and effective dose of three groups of tube voltages of CCTA measured by the InpactDose 2.0 was lower than those as measured by anthropomorphic phantom study.The relative error of both methods was within ± 50％.Conclusions Monte Carlo software can be used to estimate the levels of radiation dose during CCTA examination with a tolerable error within the acceptable range.

BACKGROUND: Body mass index(BMI)is a commonly used phenotype for obesity,which is determined by multiple genetic factors.OBJECTIVE: To investigate whether osteocalcin(also known as bone Gla protein,BGP)Hind Ⅲ genetic polymorphism is associated with BMI variation.METHODS: A total of 390 premenopausal women from a local population of Nanchang City were selected.Body weight and height were measured.All participants were genotyped at the BGP Hind Ⅲ locus using polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP).RESULTS AND CONCLUSION: The BGP genotype frequencies of HH,Hh and hh were 0.077,0.408 and 0.515,respectively.The distribution of BGP Hind Ⅲ genotypes was consistent with Hardy-Weinberg equilibrium(P > 0.05).The BGP Hind Ⅲ were significantly associated with BMI(P=0.002),which could explain about 5.47% of BMI variation.On average,BMI of individuals with HH genotype was the highest[(22.81±0.73)kg/m2],individuals with Hh genotype was intermediate[(21.50±0.53)kg/m2],while individuals with hh genotype was the lowest[(20.23±0.63)kg/m2].Therefore,carriers of HH and Hh genotypes had,respectively,approximately 12.75% and 6.28% higher BMI than carriers of the hh genotype.To our best knowledge,this is the first study reporting the association of BGP Hind Ⅲ genetic polymorphism and BMI in healthy premenopausal women.

Objective To investigate the influence of acquisition time of C-arm cone-beam CT on image quality and radiation dose of cerebral angiography.Methods C-arm cone-beam CT of cerebral angiography was performed on the male anthropomorphic head phantom,with DynaCT imaging mode and the acquisition time of 5 s,8 s and 20 s were used.Scanning was performed with each acquisition time for three times,and VR,MIP and MPR images were reconstructed.The attenuation values and their standard deviations of intracranial segment of the internal carotid artery (ICA),middle cerebral artery(MCA),anterior cerebral artery(ACA) and uniformed brain tissues were measured to calculate the image noise,signal to noise ratio (SNR) and contrast to noise ratio (CNR).We used the image noise,SNR and CNR as the objective standard to evaluate the image quality,and One-way ANOVA analysis of variance was used to assess the difference among them.A scale with scores 1 to 5 was used to rate the quality of the reconstructed image of ICA,MCA,ACA as a subjective evaluation,the difference among the evaluation scores were analyzed using Kruskal-wallis.We recorded the dose area product (DAP) of each acquisition time and the effective dose(ED) was calculated to assess the radiation dose,the difference among them were analyzed using One-way ANOVA analysis of variance.Results In C-arm cone beam CT 20 s imaging,the SNR of intracranial segment of the ICA,M CA,ACA were 22.29± 1.41,29.36 ±0.11 and 23.13 ±2.10 respectively,in 5 s imaging13.83 ±0.61,14.65 ±0.16 and 12.79±0.19 respectively,in 8 s imaging 14.92±0.96,18.97 ± 1.24 and 16.65 ±0.46 respectively,all the results showed a significant difference (F valued 58.19,327.29,52.74 respectively,all P valued＜0.01),the CNR of 20 s imaging were higher than that of 5 s and 8 s imaging,the Noise of ICA,MCA,ACA and the uniformed brain tissues of 20 s imaging were lower than that of 5 s and 8 s imaging,all the results showed significant difference (all P valued＜0.01).The subjective evaluation scores of VR imaging of 5 s,8 s and 20 s were 3.61 ±0.49,4.06±0.53,4.72±0.45 respectively,the scores of MIP imaging were 3.42±0.50,3.83±0.65 and 4.50±0.51 respectively,the scores of MPR imaging were 2.83±0.45,3.14±0.35 and 3.67±0.49 respectively,all the results showed significant difference (x2 valued 51.29,42.25 and 43.56 respectively,all P valued ＜0.01).The DAP values in C-arm cone beam CT 5 s,8 s and 20 s imaging were (9.11 ±0.18),(13.81±0.75)and(58.62±0.62)Gy· cm2,ED values were (0.91 ±0.02),(1.38±0.75)and(5.84± 0.11) mSv,all the results showed significant difference (F valued 3 720.30 and 3 654.85 respectively,all P valued＜0.01).Conclusion The image quality and radiation dose of C-arm cone-beam computed tomography are closely correlated with acquisition time.

Objective To compare the differences of pulmonary nodule detection rates between iterative reconstruction (sinogram affirmed iterative reconstruction,SAFIRE)algorithm and filtered back projection (FBP) algorithm in chest CT, and to evaluate the detection accuracy.Methods Three groups of tube voltage values of 80,100,and 120 kV were defaulted on the new dual-source CT,with automatic mAs care dose 4D technology, the chest phantom with simulated pulmonary nodules was scanned, then the images were reconstructed with FBP and SAFIRE (grade 1-5 ),respectively. The detection rates of simulated pulmonary nodules in the chest CT images reconstructed of SAFIRE (grade 1-5 )and FBP were compared, and their diameters and CT values were measured.Results With the same tube voltage, no significant difference was found in the detection rate of simulated pulmonary nodules between SAFIRE (grade 1-5 )and FBP (P>0.05 ), the diameter deviation of simulated nodules of SAFIRE (grade 3 )was less than FBP, and the difference in the average CT value of the simulated nodules between SAFIRE (grade 3)and FBP was not statistically significant (P>0.05);the simulated nodule detection rate of 100 kV was equivalent to the detection rate of 120 kV,the simulated nodule (-800 HU and 3 mm )detection rate of 80 kV was less than that of 120 kV;as the tube voltage reduced,or simulated nodule diameter decreased,or the density of simulated nodule reduced,the nodule’s diameter deviation was increased. Conclusion Compared with FBP,the capabilities of SAFIRE in pulmonary nodule detection in different densities and different sizes are same,and SAFIRE algorithm is helpful for accurate displaying of pulmonary nodules,and it can be used for low-dose CT lung cancer screening program.