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Objective:To evaluate the application of amide proton transfer weighted (APTw) magnetic resonance imaging(MRI) for grading of brainstem glioma (BSG) in children.Methods:Twenty-five children (16 males and 9 females) aged 0.7-12.4(5.6±3.3)years were diagnosed as BSG by surgery or biopsy in Beijing Children′s Hospital from December 2019 to March 2022, including 13 cases of low-grade BSG and 12 cases of high-grade BSG. APTw imaging and conventional MRI were performed on a 3.0 T MRI scanner. The differences in gender distribution, age, conventional MRI appearance, APTw signal intensity and apparent diffusion coefficient (ADC) between children with high and low grade BSG were analyzed. Receiver operating characteristic (ROC) curve was used to analyze the efficacy of APTw signal intensity in the differential diagnosis of high and low grade BSG, and Youden index was calculated to obtain the optimal diagnostic threshold. Pearson′s correlation coefficient analysis was used to evaluate the correlation between APTw signal intensity and Ki-67 expression.Results:There was no significant difference in age and gender distribution between high-grade and low-grade BSG patients. The maximum diameter of high-grade BSG was significantly larger than that of low-grade BSG [(4.7±0.9) vs. (3.1±1.7)cm; t=-2.94, P=0.007]; the maximum signal intensity of APTw (APTw max) in high-grade BSG was significantly higher than that in low-grade BSG [(4.9±0.6)% vs. (3.0±1.2)%; t=-5.14, P<0.001]; the average signal intensity of APTw (APTw mean) in high-grade BSG was significantly higher than that in low-grade BSG[(3.6±0.4%) vs. (2.7±1.1)%; t=-2.66, P=0.014].The area under the curve(AUC)of APTw max in distinguishing high-and low-grade BSG was 0.897; with 4.07% as the optimal diagnostic threshold of APTw max, the sensitivity for the diagnosis of high-grade BSG was 0.917 and specificity was 0.846. The AUC of APTw mean in distinguishing high-and low-grade BSG was 0.769; with 2.85% as the optimal diagnostic threshold of APTw mean, the sensitivity for the diagnosis of high-grade BSG was 0.917 and specificity was 0.692. There was a positive correlation between the value of APTw max and Ki-67 expression( r=0.453, P=0.023). Conclusion:APTw imaging is helpful to distinguish high-grade and low-grade BSG in children. APTw max value can be used to effectively evaluate the proliferative activity of BSG in children.
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Objective Quantitative imaging evaluation was performed on the liver and spleen system lesions of patients with Gaucher disease after treatment. in order to deepen the understanding of Gaucher disease. Methods From August 1999 to August 2018, we registered, examined and treated children with Gaucher disease, and conducted quantitative imaging research on 40 children with Gaucher disease who were intensively followed up in Beijing Children's hospital, Capital Medical University until August 2018. At the same time, 34 normal volunteers were matched. All subjects were scanned with magnetic resonance imaging(MRI). The fat fraction(FF), iron content(R2*), standard apparent diffusion coefficient(sADC), slow apparent diffusion coefficient(D), fast apparent diffusion coefficient(D*) and perfusion fraction(f)of the liver and spleen were measured. The quantitative parameter values measured by patients with Gaucher disease and normal subjects were statistically analyzed by independent sample t-tests. Results The results showed that there was no significant difference in FF, R2*, sADC, D, D*, f of the liver and spleen, and liver elasticity was also within the normal range. However, the volume of liver and spleen in patients was significantly different from that in normal subjects. Conclusions After treatment, the volume of the liver and spleen in patients with Gaucher disease is greater than that of normal people, but other quantitative parameters are within the normal range, indicating that long-term enzyme replacement therapy can delay the progress of liver and spleen diseases to a certain extent. Quantitative imaging has a certain value in the evaluation of Gaucher disease.
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Objective To explore the clinical value of 3D fast spin echo with an extended echo train acquistion (CUBE) T1WI enhancement sequence for purulent meningitis by comparing to contrast?enhanced T2WI?FLAIR sequence in the detection of lesions. Methods From August 2016 to July 2017, children with clinically suspected purulent meningitis underwent cranial magnetic resonance examination in our hospital. There were 35 children, 19 males and 16 females, aged 2 months to 3 years (median age 8 months) in total.A GE Discovery MR 750 3.0 T scanner was used to perform routine plain and enhanced scan in all children. After enhancement, the sequences of CUBE T1WI and FLAIR T2WI were applied randomly. Using the FLAIR T2WI enhancement sequence as the reference, we evaluated the detection rate of CUBE T1WI enhancement sequence for dura mater and leptomeningeal thickening. The number of enhanced lesions detected was tested by χ2 test. Results The enhanced FLAIR T2WI sequence showed 21 cases with dural enhancement, showing a rate of 60.0%. The enhanced CUBE T1WI sequence showed 31cases with dural enhancement, showing a rate of 88.6%. There were significant differences between the dural lesions detected(χ2＝6.058, P<0.01). The enhanced FLAIR T2WI sequence showed 16 cases of leptomeningeal enhancement,showing a rate of 45.7%. The enhanced CUBE T1WI sequence showed 19 cases of leptomeningeal enhancement,showing a rate of 54.3%.The enhanced CUBE T1WI sequence was not significantly higher than that of enhanced T2WI?FLAIR sequence in displaying leptomeningeal enhancement (χ2=0.229, P>0.05). Conclusion Enhancement of the CUBE T1WI sequence enables better visualization of meningeal thickening than FLAIR T2WI. It has great clinical value in the diagnosis of purulent meningitis in children.
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Objective To validate bioelectrical impedance analysis(BIA) for measuring the area of visceral fat of school-age populations using MRI as a reference method.Methods Sixty healthy children (30 boys and 30 girls) aged 7 to 18 years were enrolled in the study.Both MRI and BIA were completed in seven days.We obtained the indexes of the body composition from BIA and MRI in the morning before the participants had their breakfast.For reference,the navel plane image obtained with MRI was used to analyze the area of adipose tissue.With BIA,the area of visceral adipose tissue could be derived directly.Results Sixty healthy school-age children were enrolled in the study.The average age of the school children was (11.9±4.6) years,and their BMI was (22.8±7.3) kg/m2.The average area of visceral fat obtained with BIA was (85.4±64.2) cm2,which was higher than that obtained with MRI [(49.4±32.4) cm2](t=-6.524,P =0.000).The Pearson correlation coefficient was r=0.806 (P=0.000) and the simple linear regression equation for the areabetween the two was:y=0.41x + 14.78;β (95％CI) was 0.41(0.04-0.81).The Bland-Altman plot was (x-) ±1.96 s:(35.9± 83.7) cm2.Conclusion BIA is comparable to MRI for assessing the area of visceral fat and is a reliable and simple tool to evaluate the visceral fat area in school-age children.