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Objective:To investigate the effect of adjusting density exposure steps on image quality and radiation dose in digital mammography.Methods:Using the automatic exposure control (AEC) mode of the digital mammography machine, five different gland thicknesses of 4.3, 5.3, 6.3, 7.3, and 8.3 cm were simulated by attaching 0, 1, 2, 3, and 4 PMMA plexiglass plates under the RMI-156 modal body, and the density exposure steps were adjusted to -3, -2, -1, 0, 1, 2, 3, and 4 for each thickness. The target/filter combination, tube voltage, tube current, incident body surface dose (ESD), incident surface air kerma (ESAK), half-value layer (HVL) and the average glandular dose displayed by the device (displayed AGD) were recorded at each step and thickness, and the signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), figure of merit (FOM) and the calculated average glandular dose (calculated AGD) were calculated. Then, the display effects of simulated fibers, simulated calcifications and simulated masses within the modal body were scored subjectively, and the changes in image quality and radiation dose at different steps were analyzed, and the relationships between ESD and ESAK, displayed AGD and calculated AGD, and displayed AGD/ESD and calculated AGD/ESAK were analyzed. A linear fit was used for the steps with SNR, CNR, and FOM, and an exponential function curve fit was used for the steps with mAs, ESAK, and calculated AGD. The differences between ESD and ESAK, displayed AGD and calculated AGD, and displayed AGD/ESD and calculated AGD/ESAK were analyzed by paired-samples t test. Results:The CNR and SNR of mammographic images rose and fell by about 8% with each increase or decrease of one step. The scores of image simulated fibers, simulated calcifications, and simulated masses showed an overall upward trend with increasing steps, but there were still cases where the scores decreased with increasing grades. FOM varied from 97% to 104% at each grade with little variability. ESD, ESAK, displayed AGD, and calculated AGD, which could measure radiation dose, showed an exponential trend of increasing function with increasing steps, with a variation of about 63% to 165%. There were statistically significant differences ( t=-9.61, P=0.001) between ESD (15.14±10.08) and ESAK (16.66±11.07). However, there were no statistically significant differences ( t=1.20, P=0.240) between displayed AGD and calculated AGD, which were 3.66±2.18 and 3.61±1.99, respectively. Conclusions:The adjustment of density exposure steps can make the image quality change linearly and the radiation dose change exponentially with increasing speed, and the mode and magnitude of the adjustment are appropriately stable with high application value.
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Objective:To evaluate the effect of reducing mAs on image quality when different target/filter combinations are used in digital mammography.Methods:In different target/filter combinations, based on the mAs of automatic exposure control(AEC), the reduction of mAs by 10%, 20%, 30%, 40% and 50% respectively were used to expose the phantom with 4.4 cm thickness. The contrast to noise ratio(CNR), signal to noise ratio(SNR), figure of merit(FOM)and average glandular dose(AGD) of the resulting image were calculated. While the image quality was ensured, the optimal mAs and the corresponding AGD under the two target/filter combination were conducted by calculating the FOM. The image features of three tissues of phantom were subjectively evaluated, and the relationship between the calculated AGD and displayed AGD was compared. The mAs that meets the image quality requirements is corresponded with the density exposure gear, and the average values of the mAs for two method were calculated and compared.Results:In two targets/filters combinations, the displayed AGD was less than the calculated AGD, and Mo/Mo was underestimated by 22.5% to 23.7%. The calculated and displayed AGD values were statistically different ( F=4 982.86, 5 555.48, P<0.05). W/Rh was underestimated by 13.1% to 14.2%. The calculated and displayed AGD values were statistically different ( F=18 859.09, 15 973.55, P<0.05). In the Mo/Mo combination, when the mAs was reduced by 20%, the FOM could be increased by 9.6% for the maximum value, and the calculated AGD was decreased by 18.8%. In the W/Rh combination, when the mAs was reduced by 10%, the FOM was increased by 5.1% for the maximum value, and the calculated AGD was decreased by 11.9%. While the image quality was ensured, the mAs was reduced by 30% for evaluating simulated fibers, and by 20% for evaluating simulated specks in the two targets/filter combinations. For evaluating simulated masses, Mo/Mo combination reduced the mAs by 40%, and the W/Rh combination reduced the mAs by 30%. And the image quality scores in above were not significantly different from those in AEC method ( P>0.05). The density exposure gear(-1 to -3) could correspond with the reduced mAs(10%-30%). Conclusions:Under different target/filter combination, the tube mAs could be reduced when the image quality was ensured.
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<p><b>OBJECTIVE</b>To observe the effect of early acupuncture intervention on brain edema in patients with traumatic intracerebral hematoma and explore its mechanism on the basis of conventional western medicine.</p><p><b>METHODS</b>With stratified block randomization, sixty-four patients with glasgow coma scale (GCS) of 6 to 12 were divided into an acupuncture combined with medicine group (a combination group) and a western medication group, 32 cases in each one. In the western medication group, dehydration to reduce intracranial pressure and nutritional nerves were given as the basic treatment. In the combination group, on the basis of the treatment as the western medication group, acupuncture was applied at Xuehai (SP 10), Taixi (KI 3), Fenglong (ST 40), Yinlingquan (SP 9), Zusanli (ST 36), etc. The treatment was given once every day, for 6 times as one course; there was an interval of 1 day between two courses; a total of 4 courses were required. GCS score and recovery time were recored before treatment and on the 7 th, 14 th and 28 th days. 90 days follow-up after treatment, the GOS was observed, and the mortality and effective survival rate were calculated. The Barthel index (BI) score was evaluated before treatment and on the 14th, 21st, 28th days and 90 days follow-up after treatment. Before treatment and 3rd, 7th, 14th, 21st, 28th days, cranial CT or MR scan was performed to calculate the brain edema index (BEI); Plasma interleukin-6 (6IL-6), neuropeptide Y (NPY) and nitric oxide (NO) were measured before treatment and on the 3rd, 7th and 14th days after treatment.</p><p><b>RESULTS</b>(1) The GCS scores increased gradually in the two groups during treatment, and there was significant difference between the 28th days and before treatment (both <0.05). There were no significant difference between the two groups about GCS score and average recovery time on the 28th days treatment (all >0.05). (2) The mortality rate of the combination group was 6.3% (2/32) on 90 days follow-up, 9.4% (3/32) in the western medication group (>0.05). The effective survival rate was 81.3% (26/32) in the combination group, which was higher than 59.4% (19/32) in the western medication group (<0.05). (3) The BI score was significantly higher than that before treatment on the 28th days and 90 days follow-up in the two groups (all <0.05), and the result in the combination group was superior to that in the western medication group (both <0.05). (4) The BEI decreased on the 14th, 21st and 28th days in the two groups (all <0.05), and on the 14th day, the BEI decreased more significantly in the combination group than that in the western medication group (<0.05). (5) The levels of IL-6, NPY and NO decreased on the 7th and 14th days in the two groups (all <0.05), and decreased more significantly in the combination group than that in the western medication group on the 7th day (<0.05).</p><p><b>CONCLUSION</b>On the basis of conventional western medicine, early acupuncture can reduce cerebral edema and improve the prognosis of patients, and acupuncture combined with medicine are superior to western medicine alone. Acupuncture mechanism may be related to reducing the expression of inflammatory response.</p>
Subject(s)
Humans , Acupuncture Points , Acupuncture Therapy , Cerebral Hemorrhage , Therapeutics , Combined Modality Therapy , Hematoma , TherapeuticsABSTRACT
Due to the insufficient supply of embryonated chicken eggs,the preparation of large quantities of inactivated influenza vaccines will require an alternative virus culture system after the emergence or reemergence of a pandemic influenza virus.The Vero cell is one of the ideal options since it was used for producing many kinds of human vaccines.However,most of the influenza viruses can not grow well in Vero cells.To develop a new influenza vaccine with Vero cells as a substrate,the virus needs to adapt to this cell substrate to maintain high growth characteristics.By serial passages in Vero cells,the B/Yunnan/2/2005va(B)strain was successfully adapted to Vero cells,with the hemagglutination titer(HAT)of the virus reaching 1:512.The high growth characteristic of this strain is stable up to 21 passages.The strain was identified by hemagglutination inhibition (HAI)test and sequencing respectively;the HA;gene sequence of the virus was cloned and analyzed.The screening and establishment of high growth B virus provides an important tool for influenza vaccine production in Vero cells.