Objective To study algorithm expression of the optimal reconstruction increment with which images could be reconstructed without loss of z-direction spatial resolution for multislice spiral CT.Methods Using Gauss function and signal sampling principle,an algorithm expression was deduced to calculate the optimal reconstruction increment with which images could be reconstructed without loss of zdirection spatial resolution.Spiral slice sensitivity profile (SSP) phantom was scanned using Somatom Sensation 64-slice spiral CT and temporal bone protocol as those used for clinic,axial images were reconstructed with slice thickness of 0.600 mm and increment of 0.100,0.300,0.400 and 0.500 mm respectively.Then SSPs and full width at half maximum (FWHM) were measured and modulation transfer functions were obtained by Fourier transfer from SSPs.Axial CT scan of 7 normal temporal bones in 6 patients were obtained by the same CT system and parameters as above.Coronal MPR images of temporal bone out of different reconstruction increment were obtained and the quality of reconstructed images were independently assessed by three senior radiologists using a four-point scale and blinded the information of reconstruction.Experimental data were processed and two-way ANOVA(in which Dunnett t test was selected for multiple comparisons) was performed with statistic software SPSS10.0.P ＜ 0.05 was considered as significant difference.Results (1) The measured FWHM of reconstruction slice thickness of 0.600 mm was 0.665 mm,so the optimal reconstruction increment calculated with the algorithm expression in this article was 0.296 mm(≈0.300 mm).Objective evaluation showed that there was obviously aliasing in high spatial frequency range of MTF curve when reconstruction increment was more than 0.300 mm,i.e.both 0.400 and 0.500 mm.Clinical scores of coronal MPR images of temporal bone reconstructed with different increment had significant difference(F =505.374,P ＜ 0.01).Treating reconstruction increment of 0.100 mm as a control group and comparing another groups against it,there was no significant difference for reconstruction increment of 0.300 mm (t =-0.222,P ＞ 0.05),while there were significant difference for 0.400 and 0.500 mm (t =-1.333、-15.889,P ＜ 0.05,P ＜ 0.01).Conclusion It was proved that the angorithm expression deduced in this article was proper because of the consistence between the calculated value and the results from objective and clinical evaluation.The optimal reconstruction increment without loss of z-direction spatial resolution is 0.445 times as large as FWHM for multislice CT.

Objective To investigate the best weighting of adaptive statistical iterative reconstruction (ASIR) algorithm and optimized low-dose scanning parameters in thoracic aorta CT angiography(CTA).Methods Totally 120 patients with the body mass index (BMI) of 19-24 were randomly divided into 6 groups.All patients underwent thoracic aorta CTA with a GE Discovery CT 750 HD scanner (ranging from 290-330 mm).The default parameters (100 kV,240 mAs) were applied in Group 1.Reconstructions were performed with different weightings of ASIR (10％-100％ with 10％),and the signal to noise ratio (S/N) and contrast to noise ratio (C/N) of images were calculated.The images of series were evaluated by 2 independent radiologists with 5-point-scale and lastly the best weighting were revealed.Then the mAs in Group 2-6 were defined as 210,180,150,120 and 90 with the kilovoltage 100.The CTDIvoland DLP in every scan series were recorded and the effective dose (E) was calculated.The S/N and C/N were calculated and the image quality was assessed by two radiologists.Results The best weighing of ASIR was 60％ at the 100 kV,240 mAs.Under 60％ of ASIR and 100 kV,the scores of image quality from 240 mAs to 90 mAs were(4.78 ±0.30)-(3.15 ±0.23).The CTDIvol and DLP were 12.64-4.41 mGy and 331.81-128.27 mGy,and the E was 4.98-1.92 mSv.The image qualities among Group 1-5 were nor significantly different (F =5.365,P ＞ 0.05),but the CTDIvol and DLP of Group 5 were reduced by 37.0％ and 36.9％,respectively compared with Group 1.Conclusions In thoracic aorta CT Angiography,the best weighting of ASIR is 60％,and 120 mAs is the best mAs with 100 kV in patients with BMI 19-24.

Objective To evaluate the effect of isoflurane or sevoflurane inhalation before and after gestation on the offspring brain development. Methods Thirty female adult Sprague Dawley rats were randomly assigned into 5 groups(n=6 each):control group(group C),group that ex?posed to isoflurane with the concentration of 1.6%for 6 hours before gestation(group BI),group that exposed to isoflurane with the concentration of 1.6%at the 6th,10th,14th and 18th day for 6 hours(group PI),group that exposed to sevoflurane with the concentration of 2.4%for 6 hours before gestation(group BS),and group exposed to sevoflurane with the concentration of 2.4%at the 6th,10th,14th and 18th day for 6 hours after gestation (group PS). Twelve offspring rats from pregnant rats in each group were chosen on the day of birth(T1),and 7th,14th and 28th days after birth(T2, T3 and T4)and sacrificed,and the hippocampi were then isolated. Hematoxylin and eosin stain were adopted to observe the tissue pathological change. Electron microscope was used to observe the neuron ultrastructure change of hippocampus. Immolunohistochemistry was used to detect cas?pase?3,the expression of growth associated protein?43(GAP?43)and neuronal nitric oxide synthase(nNOS). Results Compared with group C, no significant change was found in caspase?3,GAP?43 and nNOS expression in offspring rat hippocampus in groups BI and BS(P>0.05),and no damage change in hippocampal was seen by HE staining and electron microscopy. In group PI and PB,the expression of caspase?3 was significantly up?regulated,the expression of GAP?43 and nNOS was down?regulated at T1 to T3(P<0.01),and structural changes in cell were seen by electron microscopy. In group PI,significant pathological changes in hippocampal were seen by HE staining at T1 to T3. Compared with group PI,the expres?sion of GAP?43 and nNOS was significantly up?regulated(P<0.01),and the expression of caspase?3 was down?regulated at T1 to T3(P<0.01). Conclusion Isoflurane or sevoflurane inhalation before gestation does not affect the offspring brain development,while isoflurane or sevoflurane in?halation after gestation can induce transient abnormal change of offspring brain development,and isoflurane′s toxicity was greater than sevoflurane.

Objective To study the difference of image quality and radiation dose between different exposure modes with full-field digital mammography (FFDM).Methods The Fluke18-220mammographic phantom was exposed by FFDM system with different exposure modes at automatic exposure control ( AEC ) ,including contrast mode,standard mode and dose mode,and the exposure factors and radiation dose were recorded.The images on monitor with the best window width and window level were read by four independent radiologists.The images of specks groups,nylon fibers and masses was assessed by the four experienced readers at the criterion of American College of Radiology.Results The detection of specks groups,nylon fibers and masses were statistically different at the contrast mode and standard mode (F =41.321,P ＜ 0.05),further at the contrast mode and dose mode.The detection of specks groups、nylon fibers and masses were not statistically different( P ＞ 0.05 ) at standard mode and dose mode,but the radiation doses were different.The ESD at standard mode and dose mode was 4.5 and 3.15 mGy,respectively.The AGD of standard mode and dose mode was 1.18 mGy and 0.78 mGy,respectively.Conclusions The standard mode and dose mode of FFDM might be fit for most patients,especially at the dose mode.Contrast mode of FFDM should be strictly controled in use.

Objective To investigate the different distribution and expression of mammalian target of rapamycin complex (mTORC) in the kidney of diabetic nephropathy (DN) mice.Methods Fourteen eight-week-old male C57BL/6 mice were assigned to 2 groups: the control group ( n=7 ) and the streptozotocin ( STZ )-induced DN group ( n=7 ) . Blood and urinary variables including glucose , albumin, creatinine and albumin/creatinine ratio were assessed 2 weeks after STZ injection.Hematoxylin-eosin staining was performed for renal pathological analyses .The distributions of mTOR , phosph-ser2448-mTOR(p-mTOR), mTORC1(Raptor), mTORC2(Rictor) and phosph-ser240/244-S6K1 (p-S6K1) were determined by immunofluorescence.The expression levels of mTOR, p-mTOR, mTORC1(Raptor), mTORC2(Rictor), S6K1 and p-S6K1 were detected by Western blotting .Results Two weeks after STZ injection , the diabetic mice developed albuminuria (P<0.01) and renal hypertrophy (P<0.05).The immunofluorescence positive staining for mTOR , Raptor, and Rictor was distributed in the epithelial cells of proximal tubules , glomerular mesangium and capillary loops as well as the medullary collecting ducts of the control mouse kidney .These positive signals increased in the DN mouse kidney ( P<0.05).However, pS6K1 was not detected in the inner medulla of control mouse and p-mTOR was not found in the glomeruli of both control and DN mice .Conclusion mTORC is widely expessed in the mouse kidney and participates in the development of DN , whereas the 2448 serine phosphorylation of mTOR may be not implicated in the hyperglycemia mediated glomerular injury .

Objective To investigate the effect of different noise index (NI) combined with iterative recombination on the image quality and radiation dose of CT scan in patients with different body mass index (BMI). Method One hundred and sixty patients who had a liver CT enhanced scan were divided into group A (18 kg/m2≤BMI<24 kg/m2 ) and group B (24 kg/m2≤BMI<31 kg/m2) according to BMI, and each group had 80 patients. The two groups were randomly divided into 4 subgroups which NI value was 11, 13, 15 and 17 respectively. All images were restructured with 50% adaptive statistical iterative reconstruction. Subjective evaluation, objective evaluation [signal noise ratio (SNR) and contrast noise ratio (CNR)] and the effective dose of each group were recorded and calculated after the scan. ANOVA and Kruskal-Wallis test were used to evaluated the difference of imaging quality and radiation dose. Results In group A, the SNR, CNR and the subjective score of the later arterial phase images showed a statistical difference between NI=17 group and other subgroups (P<0.05), while there was no statistical differences among the other three subgroups during three CT enhanced phase. The average ED of NI=15, 17 group were decreased by 57.56%(2.17/3.77) and 61.54% (2.32/3.77) compared with NI=11 group, respectively. In group B, the SNR, CNR and the subjective image scores of the later arterial phase showed a significant difference between NI=15 and NI=11, 13 group (P<0.05). There was a statistically difference of image quality in group NI=17 compared with the other three subgroups in the later arterial phase, portal venous phase and equilibrium phase (P<0.05). The average ED of NI= 13, 15 group was decreased by 26.41% (1.69/6.40) and 45.31%(2.90/6.40) compared with NI=11 group, respectively. Conclusion Upon maintaining diagnostic imaging quality, setting different NI according to BMI and applying the iterative reconstruction algorithm can effectively reduce the radiation dose of liver CT enhanced scanning.

Objective To investigate the image quality,radiation dose and iodine intake of CT pulmonary angiography (CTPA) in patients using low tube voltage (100 kVp) combination of different noise indexes (NI) and low concentration contrast agent.Methods A total of 80 patients with suspected pulmonary embolism (PE) and other pulmonary diseases who had undergone CTPA were divided into four groups (A,B,C and D),with 20 patients in each group.Group A underwent 120 kVp CT scan protocol in combination with NI=25 and 370 mg iodine/ml contrast agent,while groups B,C and D underwent 100 kVp CT scan protocol in combination with NI=30,35,40,and 320 mg iodine/ml contrast agent,respectively.All images were restructured using 60％ adaptive statistical iterative algorithm 2.0.Objective image quality evaluation included CT values of pulmonary artery,noise values of pulmonary artery,signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR).Subjective image evaluation used a 5-point scoring method and was conducted by two independent radiologists.The CT dose index of volume (CTDIvol),dose-length product (DLP) and iodine intake was recorded,and the mean value was calculated.The DLP was converted to the effective dose (ED).Analysis of Variance or Kruskal-Wallis test was used to evaluate the differences among the four groups in terms of image quality,radiation dose and iodine intake.Results There was a significant difference in CT values of pulmonary artery among the groups A,B,C and D (P＜0.05),and the CT values of pulmonary artery of group A was the lowest.There was no significant differences in noises of pulmonary artery,SNR,CNR and subjective indexes scores among the groups A,B,C and D (P＞0.05).There was a significant difference in iodine intake among the groups A,B,C and D,iodine intake of the group A was the highest,iodine intake of the group D was the lowest.The iodine intake of groups B,C and D decreased by 12.4％ (42/340),13.2％ (45/340) and 15.0％ (51/340) relative to group A,respectively.There was a significant difference in radiation dose among the groups A,B,C and D,The CTDIvol,DLP and ED of group D decreased by 45.3％ (3.9/8.6),48.6％ (120/247) and 48.3％ (2.02/4.18) relative to group A,respectively (P＜0.01).Conclusion Low tube voltage combination with high NI value and low concentration contrast agent can more effectively reduce the radiation dose and iodine intake for CTPA while maintaining diagnostic image quality.

Objective To compare the difference of IL-8 and MMP-9 levels in the serum and sputum before and after treatment in patients with acute exacerbations of COPD,and to analyze the correlation between IL-8 and MMP-9 levels and lung function.Method A total of 20 cases of AECOPD patients were randomly selected in the observation group and 15 cases of healthy people were selected in the control group.Pulmonary function was measured and the specimens of sputum and blood were collected during the admission and discharge for AECOPD patients.FEV1 and FEV1/FVC％ were recorded,and the concentration of IL-8 and MMP-9 in the sputum supernatant and serum were tested with double antibody sandwich enzyme linked immunosorbent assay before and after treatment.All the data and correlation were analyzed with t test and SPSS software.Results (1) Before the treatment,serum IL-8 concentration in COPD patients was 28.30 ± 14.39 pg/mL,higher than that in the control group [17.46 ± 3.48) pg/mL,P=0.008].After treatment,the serum IL-8 concentration was significantly decreased [(13.30 ± 6.31) pg/mL,P=0.000].IL-8 concentration of sputum significantly decreased after treatment [(501.60 ± 508.61) pg/mL,P=0.042] than one before treatment (639.40 ± 703.12) pg/mL.(2) Before treatment,serum MMP-9 concentration in patients with AECOPD was 1.12 ± 0.36 ng/mL,lower than control group [(17.89 ± 11.00) ng/mL,P=0.000)].After treatment,the serum MMP-9 concentration was significantly decreased [(0.87 ± 0.31) ng/mL,P=0.000].MMP-9 concentration of sputum before treatment (12.04 ± 12.22) ng/mL decreased significantly after treatment [(8.02 ± 7.13) ng/mL,P=0.005].(3) Before treatment,no correlation was seen between the concentration of serum IL-8 and FEV1,FEV1/FVC.Negative correlation was observed between the sputum IL-8 concentration and FEV1/FVC and no correlation was found with FEV1.After treatment,we found that no correlation showed between the concentration of IL-8 and FEV1,FEV1/FVC,and negative correlation was seen between the IL-8 concentration in sputum and FEV1,FEV1/FVC.(4) Before treatment,no correlation between the concentration of serum MMP-9 and FEV1,FEV1/FVC was observed and no correlation between the sputum MMP-9 concentration with FEV1 was seen.Negatively correlation was found between the sputum MMP-9 level wtih FEV1/FVC.After treatment,we observed no correlation between the serum concentration of MMP-9 and FEV1,FEV1/FVC,and negative correlation between the concentration of MMP-9 in sputum and FEV1,FEV1/FVC.Conclusion The concentration of IL-8 and MMP-9 in serum and sputum in patients with acute exacerbation of COPD is higher than those in the stable phase.IL-8 and MMP-9 levels in serum show no correlation with lung function.Negative correlation was observed between IL-8 and MMP-9 levels in sputum and lung function.We can test the levels of IL-8 and MMP-9 in sputum to evaluate the severity of the disease.

Objective To compare imaging quality and radiation dose of different anode filter combination for full-field digital mammography.MethodsThe image of FLUKE NA 18-220 phantom were taken at full-field digital mammography (FFDM),system with Mo/Mo,Mo/Rh,Rh/Rh anode/filter combination by automatic exposure control,record the exposure factors and doses.The images on monitor with the best window width and window level were read by 4 independent radiologists,the images of specks groups,nylon fibers and masses was assessed by the 4 experienced readers at the criterion of American College of Radiology 1999 mammography quality control manual.Statistical analysis was performed using analysis of variance.ResultsThe nylon fibers scores of Mo/Mo,Mo/Rh and Rh/Rh were 5.50 ± 2.12,4.50 ± 1.85 and 4.38 ± 1.38 ; the specks groups scores of Mo/Mo,Mo/Rh and Rh/Rh were 5.38 ± 1.98,4.25 ± 1.56 and 4.38 ± 1.38;the masses scores of Mo/Mo,Mo/Rh and Rh/Rh were 5.38 ± 1.98,4.38 ±1.68 and 4.25 ± 1.56,the detection of specks groups,nylon fibers was not statistically significant ( F =4.56 and 4.32,P ＞ 0.05 ),but the detection of masses was statistically significant ( F =36.65,P ＜ 0.05).The radiation doses were different,the entrance surface dose (ESD) and average glandular dose (AGD) of Rh/Rh were (5.11 ± 1.89) and ( 1.08 ± 0.13 ) mGy,the ESD and AGD of Mo/Mo were (6.66 ± 2.33 )and ( 1.29 ± 0.38 ) mGy,the ESD and AGD of Mo/Rh anode/filter combination were (5.67 ± 2.02) and ( 1.29 ± 0.38) mGy.ConclusionsThe radiation dose of Rh/Rh and Mo/Rh anode/filter combination of FFDM were lower,and the imaging was clear,so Rh/Rh and Mo/Rh anode/filter combination of FFDM prefer to mostly patients,especially when the thinkness is large,Rh/Rh anode/filter combination is preferred,because the kV values was higher,the penetration of X-ray was stronger.The Mo/Mo anode/filter combination was used when the needs of high-resolution,because the detection of masses of it was better.

Objective To compare the image quality and radiation dose of CTA of the kidney in patients using routine CT and the spectral imaging combination of different scanning protocols with the adaptive statistical iterative reconstruction 2.0 algorithm (ASIR 2.0). Methods A total of 90 patients who had undergone a CTA of the kidney were divided into three groups (A, B and C), with 30 patients in each group. Group A underwent a routine CT examination, and the scan parameters are:120 kVp, 30 to 650 mA, rotation time 0.5 s/r, scan FOV 50 cm × 50 cm;while groups B and C underwent spectral imaging protocol 1 and 2, the scan parameters of spectral imaging protocol 1 and 2 are:rapid dual kVp (80-140 kVp) switching in 0.25 ms, 375 mA and 360 mA, rotation time 0.7 s/r and 0.6 s/r, scan FOV 36 cm × 36 cm and 32 cm × 32 cm, respectively. All images were reconstructured using ASIR 2.0. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of all images were calculated when the kidney CTA was completed. Each subjective image evaluation used a 5-point scoring method and was conducted by two independent radiologists. The CT dose index (CTDIvol) and dose-length product (DLP) were recorded, and the mean value was calculated. The DLP was converted to the effective dose (ED). All data were compared with Kruskal-Wallis test and one-way ANOVA. Results The energy level of 49 to 56 keV was found to provide the best CNR for displaying CTA of the kidney. There were significant differences in CT values, noise, SNR, CNR and subjective score between groups B, C and A (P<0.05), and there was no significant differences in CT values, noise, SNR, CNR and subjective score between groups B and C (P>0.05). There were significant differences in ED among groups A, B and C (P<0.05), and the ED of groups A, B and C were (8.2±1.2), (5.2± 0.9) and (4.4 ± 0.7) mSv, respectively. Conclusion Spectral imaging with different scanning protocols can more effectively reduce the radiation dose than the routine CT scan mode for a kidney CTA while still maintaining diagnostic image quality, and protocol 2 of spectral imaging in our study is recommended.