Objective To investigate the metabolite changes in the preschool children with autism spectrum disorder (ASD) using MR spectroscopy (MRS) and explore the associations between image findings and clinical variables, which may provide a noninvasive brain biochemical method for the early diagnosis and prevention of autism. Methods Twenty one cases of preschool ASD children (3-6 years old) and age-and sex-matched 20 preschool healthy controls underwent single voxel short (SVS) short TE (TE=30 ms) MRS. The absolute metabolite concentrations in the anterior cingulate cortex (ACC) , anterior middle anterior cingulate cortex (aMCC) and posterior cingulate (PCC) were quantitatively analyzed using LCModel software. Two independent sample t tests were used for analysis. The relationships between metabolite concentrations and diagnostic and statistical manual of mental disorders (DSM-IV) , childhood autism rating scale (CARS) and autism behavior checklist (ABC) were analyzed by Pearson correlation analysis. Results Compared to control subjects, ASD patients had significantly lower N-acetylaspartate (NAA) values (4.35 ± 0.80, 6.34±0.82, 8.04±0.97 mmol/L respectively) in ACC, aMCC and PCC (t=2.640, P=0.012;t=2.182, P=0.035;t=3.343, P=0.002) , had significantly lower choline (Cho) 1.32±0.22 mmol/L (t=2.905, P=0.006) and glutamine and glutamate complex (Glx) 10.02 ± 0.88 mmol/L (t=2.090, P=0.043) in PCC. Cho, total creatine (tCr) , myo-Inositol (MI) and Glx levels did not differ between groups in other aforementioned regions (P>0.05). Negative correlations between the NAA ualues in the PCC and CARS (r=-0.504, P=0.020) were detected, and no significant correlation among DSM-IV, CARS, ABC and other metabolite values (P>0.05). Condnsions The biochemical changes in the preschool children with ASD in cingulate reflect the neuronal loss, structural or functional damage and cell membrane enzyme metabolic dysfunctions, may reveal the pathological basis of ASD. These results may provide noninvasive and quantitative methods for the diagnosis and prognosis evaluation of ASD child.

Objective To study the metabolic characteristics of neuronal injury in the temporal lobes during the radiotherapy in the elderly patients with nasopharyngeal carcinoma by 1H-MR spectroscopy.Methods Conventional MRI and 1H-MRS were performed in 21 elderly (age ≥60 years) and 33 young (age ≤ 45 years) patients who were historically confirmed with nasopharyngeal carcinoma and received radiotherapy for the first time.MR data were collected before and during the therapy at the radiation dosages of 20,40 and 60 Gy,respectively.Student t test was used to compare the NAA/Cr,Cho/Cr and NAA/Cho ratios of 1H-MRS in the temporal lobes between the two groups.Results The ratios of NAA/Cr,Cho/Cr before radiotherapy were 1.94 ± 0.15,1.86 + 0.20 in the elderly group,and 2.12 + 0.25,1.82 ± 0.24 in the young group respectively,but the difference was not statistically significant ( t =1.417,1.070,P ＞ 0.05 ).At the radiation with dosages of 20,40,and 60 Gy,the ratios of NAA/Cr were 1.81 ± 0.14,1.53 + 0.16,1.06 ±0.08 in the elderly group respectively,and were 2.03 ±0.16,1.92 ±0.21,1.77 ±0.18 in the young group respectively.There were statistical differences between two groups ( t =8.386,9.113,13.729,respectively,P＜0.05,＜0.05,＜0.01).The ratios of Cho/Cr were 1.82 +0.16,1.61 +0.29,1.37 +0.13 in the elderly group respectively,and were 1.77 + 0.19,1.48 + 0.17,1.06 + 0.14 in the young group respectively.There were statistical differences between the two groups at dosages of 40 and 60 Gy ( t =5.230,9.322 respectively,P ＜ 0.05 ).The ratios of NAA/Cho were 1.17 + 0.15,1.10 ± 0.08,0.83 ±0.05 in the elderly group respectively,and were 1.52 ±0.13,1.36 +0.15,1.10 +0.17 in the young group respectively.There were statistical differences between two groups ( t =5.862,2.560,9.754 respectively,P ＜0.05,＜0.05,＜0.01 ).At the dosages of 20,40 and 60 Gy,the decreases of NAA/Cr in the elderly group (6.70％,14.43％,24.23％ respectively) were more significantly higher than those in the young group(4.25％,5.19％,7.08％ respectively).The decrease of Cho/Cr in the elderly group (2.15％,11.29％,12.90％ respectively) were lower than those in the young group ( 3.30％,15.93％,17.58％ respectively).And the decrease of NAA/Cho in the elderly group (8.59％,5.47％,21.09％ respectively) were higher than those in the young group (2.56％,10.26％,16.67％ respectively).Conclusion Under the same radiotherapy pattern and radiation dosage,the injury to the neurons in the temporal lobes is significantly greater in the elderly patients than in young patients.Since the injury is smallest at the dose of 20 Gy among the doses evaluated,the intervention conducted in the elderly patients at this dose may help to minimize the injury to the neurons.

Objective To explore the clinical effect of precise radiotherapy in the treatment of cancer in elderly patients. Methods We selected 88 elderly patients with advanced cancer at our hospital from January 2012 to December 2015.The patients were assigned into a control group(n＝44) treated with conventional radiation therapy and an intervention group (n＝44)receiving precise radiation therapy.Clinical effects and treatment reactions and adverse events were compared between the two groups. Results The total effective rate was higher in the intervention group than in the control group ,but the difference was not significant [40.9%(18/44)vs 56.8%(25/44) ,χ2＝ 2.228 ,P ＝0.135] .The control rate of clinical diseases was higher in the intervention group [77.3%(34/44)]than in control group[56.8%(25/44)](χ2＝ 4.166 ,P＝ 0.041).The incidence of adverse reactions was significantly lower in the intervention group [43.2%(19/44 )] than in the control group [68.2%(30/44)] ,(χ2＝ 5.572 ,P ＝ 0.018 ). Conclusions Precise radiotherapy has a precisely clinical efficacy and a lower incidence of adverse events. It is worth recommending and generalizing.