A cross-sectional study on the correlation of image quality, effective dose, and body composition with thyroid, chest, and abdominal computed tomography scans.

Background: The rapid increase in the use of radiodiagnostic examinations in China, especially computed tomography (CT) scans, has led to these examinations being the largest artificial source of per capita effective dose (ED). This study conducted a retrospective analysis of the correlation between image quality, ED, and body composition in 540 cases that underwent thyroid, chest, or abdominal CT scans. The aim of this analysis was to evaluate the correlation between the parameters of CT scans and body composition in common positions of CT examination (thyroid, chest, and abdomen) and ultimately inform potential measures for reducing radiation exposure. Methods: This study included 540 patients admitted to Fudan University Shanghai Cancer Center from January 2015 to December 2019 who underwent both thyroid or chest or abdominal CT scan and body composition examination. Average CT values and standard deviation (SD) values were collected for the homogeneous areas of the thyroid, chest, or abdomen, and the average CT values and SD values of adjacent subcutaneous fat tissue were measured in the same region of interest (ROI). All data were measured three times, and the average was taken to calculate the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) for each area. The dose-length product (DLP) was recorded, and the ED was calculated with the following: formula ED = k × DLP. Dual-energy X-ray was used to determine body composition and obtain indicators such as percentage of spinal and thigh muscle. Pearson correlation coefficient was used to analyze the correlations between body composition indicators, height, weight, body mass index (BMI), and ED. Results: The correlation coefficients between the SNR of abdominal CT scan and weight, BMI, and body surface area (BSA) were -0.470 (P=0.001), -0.485 (P=0.001), and -0.437 (P=0.002), representing a moderate correlation strength with statistically significant differences. The correlation coefficients between the ED of chest CT scans and weight, BMI, spinal fat percentage, and BSA were 0.488 (P=0.001), 0.473 (P=0.002), 0.422 (P=0.001), and 0.461 (P=0.003), respectively, indicating a moderate correlation strength with statistical differences. There was a weak statistically significant correlation between the SNR, CNR, and ED of the other scans with each physical and body composition index (P=0.023). Conclusions: There were varying degrees of correlation between CT image quality and ED and physical and body composition indices, which may inform novel solutions for reducing radiation exposure.

Effect of virtual reality-based exercise and physical exercise on adolescents with overweight and obesity: study protocol for a randomised controlled trial.

INTRODUCTION: Obesity is a complex and multifactorial disease that has affected many adolescents in recent decades. Clinical practice guidelines recommend exercise as the key treatment option for adolescents with overweight and obesity. However, the effects of virtual reality (VR) exercise on the physical and brain health of adolescents with overweight and obese remain unclear. This study aims to evaluate the effects of physical and VR exercises on physical and brain outcomes and explore the differences in benefits between them. Moreover, we will apply a multiomics analysis to investigate the mechanism underlying the effects of physical and VR exercises on adolescents with overweight and obesity. METHODS AND ANALYSIS: This randomised controlled clinical trial will include 220 adolescents with overweight and obesity aged between 11 and 17 years. The participants will be randomised into five groups after screening. Participants in the exercise groups will perform an exercise programme by adding physical or VR table tennis or soccer classes to routine physical education classes in schools three times a week for 8 weeks. Participants in the control group will maintain their usual physical activity. The primary outcome will be the change in body fat mass measured using bioelectrical impedance analysis. The secondary outcomes will include changes in other physical health-related parameters, brain health-related parameters and multiomics variables. ETHICS AND DISSEMINATION: This study was approved by the Ethics Committee of Shanghai Sixth People's Hospital and registered in the Chinese Clinical Trial Registry. Dissemination of the findings will include peer-reviewed publications, conference presentations and media releases. TRIAL REGISTRATION NUMBER: ChiCTR2300068786.

Addition of gadolinium contrast to three-dimensional SSFP MR sequences improves the visibility of coronary artery anatomy in young children.

Objective: This study aims to compare the value of a gadolinium contrast-enhanced 1.5-T three-dimensional (3D) steady-state free precession (SSFP) sequence with that of a noncontrast 3D SSFP sequence for magnetic resonance coronary angiography in a pediatric population. Materials and methods: Seventy-nine patients from 1 month to 18 years old participated in this study. A 3D SSFP coronary MRA at 1.5-T was applied before and after gadolinium-diethylenetriaminepentaaceticacid (DTPA) injection. The detection rates of coronary arteries and side branches were assessed by McNemar's χ2 test. The image quality, vessel length, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) of the coronary arteries were analyzed by the Wilcoxon signed-rank test. The intra- and interobserver agreements were evaluated with a weighted kappa test or an intraclass correlation efficient test. Results: A contrast-enhanced scan detected more coronary arteries than a noncontrast-enhanced scan in patients under 2 years old (P < 0.05). The SSFP sequence with contrast media detected more coronary artery side branches in patients younger than 5 years (P < 0.05). The image quality of all the coronary arteries was better after the injection of gadolinium-DTPA in children younger than 2 years (P < 0.05) but not significantly improved in children older than 2 years (P > 0.05). The contrast-enhanced 3D SSFP protocol detected longer lengths for the left anterior descending coronary artery in children younger than 2 years and the left circumflex coronary artery (LCX) in children younger than 5 years (P < 0.05). SNR and CNR of all the coronary arteries in children younger than 5 years and the LCX and right coronary artery in children older than 5 years enhanced after the injection of gadolinium-DTPA (P < 0.05). The intra- and interobserver agreements were high (0.803-0.998) for image quality, length, SNR, and CNR of the coronary arteries in both pre- and postcontrast groups. Conclusion: The use of gadolinium contrast in combination with the 3D SSFP sequence is necessary for coronary imaging in children under 2 years of age and may be helpful in children between 2 and 5 years. Coronary artery visualization is not significantly improved in children older than 5 years.

Amplitude of low-frequency fluctuation may be an early predictor of delayed motor development due to neonatal hyperbilirubinemia: a fMRI study.

BACKGROUND: Acute bilirubin encephalopathy or kernicterus is the worst consequence of brain damage caused by the elevation of total unbound serum bilirubin (TSB) in neonates. The present study aimed to visualize the characteristic brain regions of neonates with hyperbilirubinemia (HB) using functional magnetic resonance imaging (fMRI) and to measure the amplitude of low-frequency fluctuation (ALFF) values. METHODS: This was a prospective cohort study, which included newborns with HB who were hospitalized at the Children's Hospital of Fudan University. The control group included neonates admitted with neonatal simple wet lung or pneumonia without neurological disease or brain injury. Newborns were divided into a severe hyperbilirubinemia group (SHB), moderate HB group, and control group based on TSB levels. The newborns completed routine MRI combined with fMRI scans and brainstem auditory evoked potentials (BAEPs) during their hospitalization. RESULTS: A total of 251 newborns were included in this study. There were 45 patients in the SHB group, 65 in the HB group, and 141 in the control group. The average ALFF value in the basal ganglia region in the SHB group was the highest, which was greater than that in the HB and control groups (P<0.001). The ALFF increased with an increase in TSB concentration. Based on the results of the Bayley Scales of infant development assessment, we further found that the most significant difference in ALFF remained in the basal ganglia region between newborns with motor development scores above 70 (including 70) and below 70. Correlation analysis revealed a strong negative correlation between motor development scores and ALFF (r=-0.691, P<0.001). When ALFF alone was used to predict motor development, the sensitivity was 89%. When ALFF was combined with TSB and BEAP results, the area under the ROC curve was the largest (AUC =0.85). The sensitivity and specificity of the model were 67.86% and 90.77%, respectively. CONCLUSIONS: The ALFF value may be able to serve as an early imaging biomarker and has a greater sensitivity than TSB or BAEP results in predicting long-term motor development (18 m) in HB.