Objective To investigate the value of multiple parameter analysis in spectral CT scanning for the diagnosis of pulmonary nodules or masses.Methods The spectral CT scanning data in arterial phase of 319 patients with pulmonary nodules or masses confirmed by pathology and/or follow-up were analyzed retrospectively.The patients were divided into 3 groups:inflammatory group,lung cancer group and tuberculosis group.The Iodine(water)concentration,water(Iodine)concentration,the effective atomic number and the CT value of 60,70 and 80 keV single energy in the leisons were measured.One way A NOVA and LSD-t test were used for statistical analysis.Results One way A NOVA showed that the Iodine(water)concentration,water(Iodine)concentration,the effective atomic number and the CT value of 60,70 and 80 keV single energy among 3 groups in the arterial phase were all statistically different(P<0.05).T he LSD-t test showed there were statistical differences of Iodine content and effective atomic number between tuberculosis group and inflammatory group,lung cancer group and inflammation group(P<0.05).There were statistical differences between tuberculosis group and lung cancer group,inflammation group and lung cancer group in water concentration(P<0.05).The statistical differences in CT value of 60,70 and 80 keV single energy between tuberculosis group and inflammatory group,inflammation group and tuberculosis group were also found(P<0.05).Conclusion Multiple parameter analysis of spectral CT scanning in arterial phase could attribute to the diagnosis and differential diagnosis of pulmonary nodules or masses.

Objective To investigate the effect of fluoxetine-exposure during pregnant period on depression-like behaviors and hippocampal BDNF in offspring mice.Methods Sixteen C57BL/6 pregnant mice were randomly divided into fluoxetine group (Flu group) and normal saline group (NS group),including 8 mice in each group.And the mice in the Flu group and NS group were treated with fluoxetine (10 mg/kg) and normal saline respectively by intragastric administration from the date of conception 9 to day 18.The adult offspring mice were divided into 8 groups including 4 subgroup with 8 in each group based on gender and circadian rhythm.That was Flu-MD group,Flu-MN group,Flu-FD group,Flu-FN group,NS-MD group,NS-MN group,NS-FD group and NS-FN group;"M" and "F" stands for gender;and "D"and "N" stands for circadian rhythm.The depression-like behavior of offspring adult mice was observed by tail suspension and forced swimming test,and the expression of brain derived neurotrophic factor (BDNF) in hippocampus was detected by Western blot.Results (1) There was no deformity in the adult offspring mice of NS group and Flu group;(2) In the tail suspension test and forced swimming test,there was no significant difference in cumulative immobility time between the Flu group and the NS group (P＞0.05).There was no significant difference in cumulative immobility time between male and female mice in NS group or Flu group (P＞0.05).There were significant differences in immobility time between Flu-MD group and Flu-MN group (tail suspension test:Flu-MD group (175.94± 30.93)s,Flu-MN group (127.65±44.91)s;forced swimming test:Flu-MD group (108.17±44.92)s,Flu-MN group (169.00±62.50) s,P＜0.05),and there were no significant difference in the rest groups.(3) There was no significant difference in the expression of BDNF protein between the Flu group and NS group (P＞0.05).Conclusion There is no phenotypic abnormalities on offspring when female mice were exposed to fluoxetine during their pregnancy period.It does not increase the occurrence of depression-like behavior of the adult offspring and does not affect the expression of BDNF in hippocampus.

Objective To analyze the radiation dose in low-dose chest CT examination of pediatric patients with mycoplasma pneumoniae pneumonia(MPP)by using size-specific dose estimation(SSDE).Methods A total of 95 patients who were scanned with low-dose chest CT were prospectively selected,65 patients with weight ≤50 kg,using 80 kV and DoseRight Z-DOM(30-50 mAs);30 patients with weight＞50 kg,using 100 kV and DoseRight Z-DOM(50-100 mAs).A total of 65 patients who were scanned with conventional chest CT were retrospectively collected,40 patients with weight ≤50 kg,25 patients with weight＞50 kg,using 120 kV,DoseRight Z-DOM(50-100 mAs)and fixed mAs.Image noise,signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)were used to objectively evaluate image quality.The subjective evaluation of image quality was performed by two radiologists using a 5-score system and a double-blind method.The volume CT dose index(CTDIvol)and dose length product(DLP)were collected,the SSDE and effective dose(ED)were measured,respectively.Results Compared with conventional scan,CTDIvol,DLP,SSDE,and ED values of 80 kV scan was decreased by 81.3％,80.3％,81.5％,and 82.4％,respectively,with a statistical difference(Z=-8.433,-8.137,-8.146,-8.142,P＜0.05).There were statistically significant differences in image noise,SNR,and CNR between 80 kV scan and conventional scan in patients with weight ≤50 kg(Z=-6.762,-5.075,-3.430,P＜0.05).In 100 kV scan,CTDIvol,DLP,SSDE,and ED values was decreased by 75.7％,76.3％,75.3％,and 75.3％,respectively,with a statistical difference(Z=-6.301,-6.173,-6.347,-6.308,P＜0.05).There were statistically significant differences in image noise and SNR between 100 kV scan and conventional scan in patients with weight＞50 kg(Z=-5.367,-4.650,P＜0.05).The subjective evaluation scores of the two groups images were all greater than 3 points,all images could be used for clinical diagnosis.SSDE was 45.3％and 29.9％higher than CTDIvol for 80 kV and 100 kV scans,respectively,SSDE was 45.7％and 28.8％higher than CTDIvol for conventional scans with weight ≤50 kg and weight＞50 kg,respectively.Conclusion Low kV combined with DoseRight Z-DOM effectively reduces radiation dose to pediatric patients with MPP;SSDE more accurately assesses radiation dose than CTDIvol in children.