Edaravone Maintains AQP4 Polarity Via OS/MMP9/ß-DG Pathway in an Experimental Intracerebral Hemorrhage Mouse Model.

Oxidative stress (OS) is the main cause of secondary damage following intracerebral hemorrhage (ICH). The polarity expression of aquaporin-4 (AQP4) has been shown to be important in maintaining the homeostasis of water transport and preventing post-injury brain edema in various neurological disorders. This study primarily aimed to investigate the effect of the oxygen free radical scavenger, edaravone, on AQP4 polarity expression in an ICH mouse model and determine whether it involves in AQP4 polarity expression via the OS/MMP9/ß-dystroglycan (ß-DG) pathway. The ICH mouse model was established by autologous blood injection into the basal nucleus. Edaravone or the specific inhibitor of matrix metalloproteinase 9 (MMP9), MMP9-IN-1, called MMP9-inh was administered 10 min after ICH via intraperitoneal injection. ELISA detection, neurobehavioral tests, dihydroethidium staining (DHE staining), intracisternal tracer infusion, hematoxylin and eosin (HE) staining, immunofluorescence staining, western blotting, Evans blue (EB) permeability assay, and brain water content test were performed. The results showed that OS was exacerbated, AQP4 polarity was lost, drainage function of brain fluids was damaged, brain injury was aggravated, expression of AQP4, MMP9, and GFAP increased, while the expression of ß-DG decreased after ICH. Edaravone reduced OS, restored brain drainage function, reduced brain injury, and downregulated the expression of AQP4, MMP9. Both edaravone and MMP9-inh alleviated brain edema, maintained blood-brain barrier (BBB) integrity, mitigated the loss of AQP4 polarity, downregulated GFAP expression, and upregulated ß-DG expression. The current study suggests that edaravone can maintain AQP4 polarity expression by inhibiting the OS /MMP9/ß-DG pathway after ICH.

Diffusion kurtosis imaging reveals abnormal gray matter and white matter development in some brain regions of children with attention-deficit/hyperactivity disorder.

In this study, we explored the application of diffusion kurtosis imaging (DKI) technology in the brains of children with attention-deficit/hyperactivity disorder (ADHD). Seventy-two children with ADHD and 79 age- and sex-matched healthy controls were included in the study. All children were examined by means of 3D T1-weighted image, DKI, and conventional sequence scanning. The volume and DKI parameters of each brain region were obtained by software postprocessing (GE ADW 4.6 workstation) and compared between the two groups of children to determine the imaging characteristics of children with ADHD. The result showed the total brain volume was lower in children with ADHD than in healthy children (p < .05). The gray and white matter volumes in the frontal lobe, temporal lobe, hippocampus, caudate nucleus, putamen, globus pallidus, and other brain regions were lower in children with ADHD than in healthy children (p < .05). The axial kurtosis (Ka), mean kurtosis (MK), fractional anisotropy (FA), and radial kurtosis(Kr) values in the frontal lobe, temporal lobe, and caudate nucleus of children with ADHD were lower than those of healthy children, while the mean diffusivity(MD) and fractional anisotropy of kurtosis (FAK) values were higher than those of healthy children (p < .05). Additionally, the Ka, MK, FA, and Kr values in the frontal lobe, caudate nucleus, and temporal lobe could be used to distinguish children with ADHD (AUC > .05, p < .05). In conclusion, DKI showed abnormal gray matter and white matter development in some brain regions of children with ADHD.

Application of dual-energy CT with prospective ECG-gating in cardiac CT angiography for children: Radiation and contrast agent dose.

OBJECTIVE: This research aimed to investigate the feasibility of utilizing dual-energy CT virtual monoenergetic images (VMI1) with prospective electrocardiogram (ECG2) gating for reducing radiation and contrast agent doses in pediatric patients with congenital heart disease (CHD3). METHODS: There were 100 pediatric patients with CHD included in this study. Group A (n = 50) underwent dual-energy scanning with prospective ECG-gating, and group B (n = 50) underwent conventional scanning with retrospective ECG-gating. Comparative analysis of CT values of lumen, objective image quality assessment, subjective image quality evaluations, and diagnostic efficacy were performed. RESULTS: CT values, image noise, signal-to-noise ratio (SNR4), and contrast-to-noise ratio (CNR5) were significantly affected by the VMI energy level, and they all increased with decreasing energy levels (P > 0.05). Combining subjective evaluation, the 45 keV VMI was considered the optimum image in group A. The 45 keV VMI exhibited higher CT values of lumen compared to conventional scanning images (P < 0.003 âˆ¼ 0.836), but meanwhile, the image noise was also higher in the 45 keV VMI (P = 0.004). Differences between the two groups in SNR, CNR, and diagnostic accuracy were not statistically significant. Compared to group B, the 45 keV VMI showed fewer contrast-induced artifacts (P < 0.001) and higher image quality score (P = 0.037). Group A had a 64 % reduction in radiation dose and a 40 % decrease in iodine dose compared to group B. CONCLUSION: The combination of dual-energy CT with prospective ECG-gating reduces radiation and iodine doses in pediatric patients with CHD. The 45 keV VMI can provide clinically acceptable image quality while declining contrast agent artifacts.

Corrigendum: Three-dimensional pseudocontinuous arterial spin labeling perfusion imaging shows cerebral blood flow perfusion decline in attention-deficit/hyperactivity disorder children.

[This corrects the article DOI: 10.3389/fpsyt.2023.1064647.].

Three-dimensional pseudocontinuous arterial spin labeling perfusion imaging shows cerebral blood flow perfusion decline in attention-deficit/hyperactivity disorder children.

Purpose: To investigate the feasibility of three-dimensional pseudocontinuous arterial spin labeling (3D-pcASL) perfusion imaging in the brain of children with Attention-deficit/hyperactivity disorder (ADHD). Methods: A total of 78 ADHD children aged 5-13 years were prospectively selected as the study group, and 89 healthy children matched in age and sex were selected as the control group. All children underwent MRI conventional sequence, 3D-pcASL, and 3D-T1 sequence scans. The brain gray and white matter volume and cerebral blood flow (CBF) perfusion values were obtained by software post-processing, and were compared and analyzed in the two groups to find out their characteristics in the brain of ADHD children. Results: The total brain volume and total CBF values were lower in ADHD children than in healthy children (P < 0.05); the gray and white matter volumes in the frontal lobe, temporal lobe, hippocampus, caudate nucleus, putamen, globus pallidus and other brain regions were lower in ADHD children than in healthy children (P < 0.05); the gray matter CBF values in the frontal lobe, temporal lobe, hippocampus, caudate nucleus, putamen, globus pallidus and other brain regions were lower in ADHD children than in healthy children (P < 0.05); the differences between the white matter CBF values of white matter in the said brain regions of ADHD children and healthy children were not statistically significant (P > 0.05); and the CBF values in frontal lobe and caudate nuclei could distinguish ADHD children (AUC > 0.05, P < 0.05). Conclusion: The 3D-pcASL technique showed reduced cerebral perfusion in some brain regions of ADHD children.

Vibration energy harvesting from tunnel invert-filling using rubberized concrete.

With the increasing operation mileage of urban rail transit, to ensure its operation safety, it is necessary to carry out health monitoring on the rail, tunnel, and other structures. How to capture the vibration energy generated by train operation and use it to monitor the power supply of sensors has become a research hotspot in recent years. In this paper, a new type of spherical energy harvester is designed for rubberized concrete tunnel invert-filling. Based on the calculation model of rubberized concrete tunnel invert-filling under train load, the vertical displacement, stress, voltage, and total electric energy are analyzed. The main conclusions are as follows: (1) The spherical energy harvester is embedded in the rubberized concrete tunnel invert-filling in the form of an array, and the optimal position is 5 mm below the sleeper. (2) Ten energy harvesters are set up in the scope of a 6-m-long rubberized concrete tunnel invert-filling. The electric energy of the millijoule level can be generated when an A-type train of 8-vehicle formation passes by. If the departure interval of 5 min/trip is calculated, the total electric energy harvesting in 1 h is 122.4 mJ. (3) Rubberized concrete tunnel invert-filling is more conducive to energy harvesting than ordinary concrete tunnel invert-filling. When the content of rubber is 10%, the total electric energy harvesting by the energy harvester array inside the tunnel invert-filling is 5% higher than that of the ordinary concrete, and the mechanical performance indexes such as stress are within the safe range. The research results of this paper have reference value for further exploration of electric energy harvesting in the running environment of rail transit trains.

Diagnosis of children with attention-deficit/hyperactivity disorder (ADHD) comorbid autistic traits (ATs) by applying quantitative magnetic resonance imaging techniques.

Objective: To explore the feasibility of applying quantitative magnetic resonance imaging techniques for the diagnosis of children with attention-deficit/hyperactivity disorder (ADHD) comorbid autistic traits (ATs). Methods: A prospective study was performed by selecting 56 children aged 4-5 years with ADHD-ATs as the study group and 53 sex- and age-matched children with ADHD without ATs as the control group. All children underwent magnetic resonance scans with enhanced T2*- weighted magnetic resonance angiography (ESWAN), 3D-PCASL, and 3D-T1 sequences. Iron content and cerebral blood flow parameters were obtained via subsequent software processing, and the parameter values in particular brain regions in both groups were compared and analyzed to determine the characteristics of these parameters in children with ADHD-ATs. Results: Iron content and cerebral blood flow in the frontal lobe, temporal lobe, hippocampus, and caudate nucleus of children with ADHD-ATs were lower than those of children with ADHD without ATs (p < 0.05). Iron content and CBF values in the frontal lobe, temporal lobe and caudate nucleus could distinguish children with ADHD-ATs from those without ATs (AUC > 0.5, p < 0.05). Conclusions: Quantitative magnetic resonance techniques could distinguish children with ADHD-ATs. Trial registration: This study protocol was registered at the Chinese clinical trial registry (ChiCTR2100046616).

Application of Quantitative Magnetic Resonance Imaging in the Diagnosis of Autism in Children.

Objective: To explore the application of quantitative magnetic resonance imaging in the diagnosis of autism in children. Methods: Sixty autistic children aged 2-3 years and 60 age- and sex-matched healthy children participated in the study. All the children were scanned using head MRI conventional sequences, 3D-T1, diffusion kurtosis imaging (DKI), enhanced T2*- weighted magnetic resonance angiography (ESWAN) and 3D-pseudo continuous Arterial Spin-Labeled (3D-pcASL) sequences. The quantitative susceptibility mapping (QSM), cerebral blood flow (CBF), and brain microstructure of each brain area were compared between the groups, and correlations were analyzed. Results: The iron content and cerebral blood flow in the frontal lobe, temporal lobe, hippocampus, caudate nucleus, substantia nigra, and red nucleus of the study group were lower than those in the corresponding brain areas of the control group (P < 0.05). The mean kurtosis (MK), radial kurtosis (RK), and axial kurtosis (AK) values of the frontal lobe, temporal lobe, putamen, hippocampus, caudate nucleus, substantia nigra, and red nucleus in the study group were lower than those of the corresponding brain areas in the control group (P < 0.05). The mean diffusivity (MD) and fractional anisotropy of kurtosis (FAK) values of the frontal lobe, temporal lobe and hippocampus in the control group were lower than those in the corresponding brain areas in the study group (P < 0.05). The values of CBF, QSM, and DKI in frontal lobe, temporal lobe and hippocampus could distinguish ASD children (AUC > 0.5, P < 0.05), among which multimodal technology (QSM, CBF, DKI) had the highest AUC (0.917) and DKI had the lowest AUC (0.642). Conclusion: Quantitative magnetic resonance imaging (including QSM, 3D-pcASL, and DKI) can detect abnormalities in the iron content, cerebral blood flow and brain microstructure in young autistic children, multimodal technology (QSM, CBF, DKI) could be considered as the first choice of imaging diagnostic technology. Clinical Trial Registration: [http://www.chictr.org.cn/searchprojen.aspx], identifier [ChiCTR2000029699].

Application of Quantitative Susceptibility Mapping in the Assessment of Iron Content in Brain Regions of Normal Children.

PURPOSE: We evaluated brain iron content in a healthy pediatric population using quantitative susceptibility mapping (QSM). METHODS: From June 2018 to December 2019, healthy subjects aged 2-18 years old (200 males, 200 females) with no anatomical abnormalities were assessed. All of the children underwent 3D T1 anatomical MRIs in addition to the sequence scans of enhanced T2 star-weighted angiography (ESWAN). The ESWAN sequence images were obtained with software to attain quantitative susceptibility mapping of the entire brain. The magnetic susceptibility values in the same brain region were compared across different age groups. The magnetic susceptibility values expressed in the same age group were compared across sexes, brain sides, and brain regions. RESULTS: The magnetic susceptibility value of each brain region increased with age, and the magnetic susceptibility value expressed by each brain region demonstrated a positive correlation with the children's age (r=0.63, P<0.05). No dramatic difference in magnetic susceptibility was observed between the brain's left side and right side in the children within the age range ≥2-<6; however, among the children within the age range ≥6-<18, the magnetic susceptibility values expressed by the left putamen nucleus, globus pallidus, and substantia nigra were higher than those expressed by the same regions on the right side (P<0.05). CONCLUSION: Quantitative susceptibility mapping can be used to evaluate the content of iron in each brain region of normal children.

Application of Three-Dimensional Pseudocontinuous Arterial Spin Labeling Perfusion Imaging in the Brains of Children With Autism.

Objective: To explore the application of three-dimensional pseudocontinuous arterial spin labeling (3D-PCASL) perfusion imaging in the brains of children with autism and to understand the characteristics of cerebral blood perfusion in children with autism. Methods: A total of 320 children with autism (160 men and 160 women) aged between 2 and 18 years and 320 age- and sex-matched healthy children participated in the study. All children were scanned by 3.0 T magnetic resonance axial T1 fluid-attenuated inversion recovery (FLAIR), T2 FLAIR, 3D-T1, and 3D-PCASL sequences. After postprocessing, cerebral blood flow (CBF) values in each brain region of children with autism and healthy children at the same age were compared and analyzed. Furthermore, CBF characteristics in each brain region of autistic children at various ages were determined. Results: The CBF values of the frontal lobe, hippocampus, temporal lobe, and caudate nucleus of children with autism are lower than those of healthy children (P < 0.05). Additionally, as the ages of children with autism increase, the number of brain regions with decreased CBF values gradually increases. A receiver operating characteristic (ROC) analysis results show that the CBF values of the frontal lobe, hippocampus, temporal lobe, and caudate nucleus can distinguish children with autism [area under the ROC curve (AUC) > 0.05, P < 0.05]. Conclusion: The 3D-PCASL shows lower brain CBF values in children with autism. Clinical Trial Registration: www.ClinicalTrials.gov, identifier: ChiCTR2000034356.

Quantitative susceptibility mapping shows lower brain iron content in children with attention-deficit hyperactivity disorder.

To investigate the feasibility of quantitative susceptibility mapping in children with attention-deficit hyperactivity disorder (ADHD), 53 children with ADHD aged 5-16 years were prospectively selected as the study group and 49 healthy children matched with age and gender were selected as the control group. All children underwent magnetic resonance imaging conventional sequence, 3D-T1, and enhanced T2*-weighted magnetic resonance angiography (ESWAN) sequence scanning. The iron content of brain regions was obtained through software postprocessing, and the iron content of brain regions of children with ADHD and healthy children was compared and analyzed to find out the characteristics of the iron content of brain regions of children with ADHD. The iron content in frontal lobe, globus pallidus, caudate nucleus, substantia nigra, putamen, and hippocampus of children with ADHD was lower than that of healthy children (p < .05). There was no significant difference in the content of iron in the left and right brain regions of children with ADHD (p > .05). The volume of frontal lobe and hippocampus of children with ADHD was lower than that of healthy children (p < .05). Iron content in brain areas such as globus pallidus, caudate nucleus, hippocampus, and putamen could distinguish children with ADHD (Area under curve [AUC] > 0.5, p < .05). Quantitative susceptibility mapping showed decreased iron content in some brain regions of children with ADHD.

Application of prospective ECG-gated multiphase scanning for coronary CT in children with different heart rates.

BACKGROUND: To investigate the application of prospective ECG-gated multiphase scanning in coronary CT imaging in children with different heart rates. METHODS: In the control group, 160 children aged 2-4 years who underwent a coronary CT examination in our hospital from May 2016 to December 2017 were retrospectively selected. They were divided into five subgroups according to their heart rate frequency: 75-85 beats/min, 86-95 beats/min, 96-105 beats/min, and 106-120 beats/min. There were 40 children in each subgroup. Each child was treated with retrospective ECG-gated scanning technology. Six groups of phase images were reconstructed: 40%, 45%, 50%, 70%, 75% and 80%. The optimal phase was selected for coronary artery reconstruction. In the study group, 240 children aged 2-4 years who underwent coronary artery CT examination in our hospital from January 2018 to May 2019 were prospectively selected and divided into five subgroups according to the heart rate frequency: 75-85 beats/min, 86-95 beats/min, 96-105 beats/min, and 106-120 beats/min. There were 60 children in each subgroup. A prospective ECG-gated multiphase scanning technique was used to reconstruct 70%, 75% and 80% phase images in the subgroups with heart rates < 85/min. In the remaining subgroups, 40%, 45% and 50% phase images were reconstructed, and the optimal phase was selected for coronary artery reconstruction. The scanning parameters, dosage of contrast medium and injection mode of contrast medium were the same in both groups. The radiation dose and image quality of the coronary artery were compared between the two groups at the same heart rate. RESULTS: When comparing the two groups at the same heart rate, the radiation dose in the study group was 72% lower than that in the control group (P < 0.05). There was no significant difference in coronary artery image quality between the two groups at the optimal phase (P > 0.05). CONCLUSIONS: Applying prospective ECG-gated multiphase scanning technology to children's coronary CT imaging can significantly reduce the scanning radiation dose without affecting the quality of the coronary artery image.

Quantitative susceptibility mapping shows lower brain iron content in children with autism.

OBJECTIVE: To explore the application of quantitative susceptibility mapping (QSM) of brain iron content in children with autism. METHODS: For the control group, 40 normal children aged 2-3, 3-4, 4-5, and 5-6 years were prospectively selected from June 2018 to December 2018, with equal numbers of males and females in each age group. For the study group, 40 children with autism aged 2-3, 3-4, 4-5, and 5-6 years were prospectively selected from January 2019 to October 2019; once again, there were equal numbers of males and females in each age group. All children received routine head MRI scans and enhanced T2*-weighted angiography (ESWAN) sequence scans, and the ESWAN sequence images were processed by software to obtain magnetic susceptibility maps. The regions of interest (ROIs) of the frontal white matter, frontal gray matter, thalamus, red nucleus, substantia nigra, dentate nucleus, globus pallidus, putamen nucleus, caudate nucleus, pons, and splenium of the corpus callosum were selected, and the magnetic susceptibility values were measured. The differences in magnetic susceptibility between the two groups were compared in children at the same age. RESULTS: For the children aged 2-3 years, the magnetic susceptibility values in the caudate nucleus, dentate nucleus, and splenium of the corpus callosum in the study group were lower than those in the control group (p < 0.05). For the children aged 3-4, 4-5, and 5-6 years, the magnetic susceptibility values in the frontal white matter, caudate nucleus, red nucleus, substantia nigra, dentate nucleus, and splenium of the corpus callosum in the study group were lower than those in the control group (p < 0.05). CONCLUSION: The brain iron content of children with autism is lower than that of normal children. TRIAL REGISTRATION: This study protocol was registered at the Chinese clinical trial registry (registration number: ChiCTR2000029699; http://www.chictr.org.cn/searchprojen.aspx ). KEY POINTS: • In this study, the brain iron content of normal children and children with autism was compared to identify the differences, which provided a new objective basis for the early diagnosis of children with autism. • This study examined the iron content values in various brain regions of normal children aged 2-6 years in this region and established a reference range for iron content in various brain regions of normal children in one geographical area, providing a reliable and objective standard for the diagnosis and treatment of some brain diseases in children. • The results of this study indicate that the brain iron content of preschool children with autism is lower than that of normal preschool children.

Application of multiple injections of contrast agent in head and neck CT arteriovenous angiography in children: Study protocol clinical trial (SPIRIT Compliant).

OBJECTIVE: To investigate the application value of multiple injections of contrast agent in head and neck CT arteriovenous angiography in children. METHODS: A total of 100 children aged 6 to 7 years who needed head and neck CT arteriovenous angiography were prospectively selected. They were randomly divided into a control group and a research group, with 50 children in each group. The same scanning parameters and reconstruction methods were used. The right median cubital vein was injected intravenously with the contrast agent Omnipaque (350 mg I/ml). For children in the control group, a bolus of undiluted contrast agent (dose was 2 ml/kg, upper limit was 50 ml) was injected 1 time. The arterial phase and vein phase of the head and neck vessels were scanned. For children in the research group, a contrast agent bolus diluted with saline to a concentration of 20% was first injected (dose was 1 ml/kg, upper limit was 25 ml), and then an undiluted contrast agent bolus (dose was 1 ml/kg, upper limit was 25 ml) was injected. Thresholds were used to trigger the scanning of the head and neck arterial phases. The CT image quality of the head and neck arteries and veins, radiation dose and contrast agent dose were compared between the 2 groups. RESULTS: Subjective evaluation of CT image quality of arteries: there were 47 cases of 4 points and 3 cases of 3 points in the control group and 34 cases of 4 points and 16 cases of 3 points in the research group. Subjective evaluation of CT image quality of veins: there were 47 cases of 4 points and 3 cases of 3 points in the control group and 5 cases of 4 points, 42 cases of 3 points and 3 cases of 2 points in the research group. The CT value of brain arterial vessel enhancement was higher in the control group than the research group, and the difference was statistically significant (P < .05). The CT value of vein enhancement was higher in the control group than the research group, and the difference was statistically significant (P < .05). The X-ray dose in the research group was 51% lower than that in the control group; the contrast agent dose in the research group was 44% lower than that in the control group. CONCLUSION: For the head and neck enhanced CT examination of children, the method of first bolus injection of 20% diluted contrast agent and later bolus injection of undiluted contrast agent can clearly demonstrate the head and neck arteries and veins one time, reducing the X-ray dose and contrast agent dose, which has clinical practical value in the enhanced CT examination of children with head and neck disease.

Application of Postlabeling Delay Time in 3-Dimensional Pseudocontinuous Arterial Spin-Labeled Perfusion Imaging in Normal Children.

OBJECTIVE: To explore the application value of postlabeling delay (PLD) in 3D pseudocontinuous arterial spin-labeled (3D-pcASL) perfusion imaging in normal children and to find the optimal PLD values for children at each age group. METHODS: Five groups of children, with 50 patients in each group, who underwent routine magnetic resonance imaging scans with normal results were included. The patients were stratified according to the following ages: younger than 1 month, more than 1 month to 6 months, more than 6 months to 12 months, more than 1 year to 3 years, more than 3 years to 6 years, and more than 6 years to 18 years. All patients received 3D-pcASL perfusion magnetic resonance scanning. The PLD values were set to 1025, 1525, or 2025 milliseconds. In subjective evaluations, the signal-to-noise ratio (SNR) and cerebral blood flow (CBF) of 3D-pcASL perfusion images under different PLD values were compared and analyzed. RESULTS: For patients in the <1-month group and >1-month to 6-month group, the images were mainly grade A when the PLD value was 1025 milliseconds, which equaled 43 and 46 cases, respectively. The brain CBF values and SNR values were higher than those of the images with PLD values of 1525 and 2025 milliseconds. For patients in the >6-month to 12-month group, >1-year to 3-year group, >3-year to 6-year group, and >6-year to 18-year group, the images were mainly grade A when the PLD value was 1525 milliseconds, which equaled 43, 45, 43, and 46 cases, respectively. The brain CBF values and SNR values were higher than those of the images with PLD values of 1025 and 2025 milliseconds. CONCLUSIONS: The optimal PLD values for 3D-pcASL perfusion imaging are different in children of different ages. The optimal PLD value for infants who are 6 months younger is 1025 milliseconds. The optimal PLD value for children older than 6 months to 18 years is 1525 milliseconds.

Application of a 3D pseudocontinuous arterial spin-labeled perfusion MRI scan combined with a postlabeling delay value in the diagnosis of neonatal hypoxic-ischemic encephalopathy.

BACKGROUND: Currently, there are many studies on the application of the 3D pseudocontinuous arterial spin-labeled (3D-pcASL) perfusion MRI technique for adult brain examinations, but few studies exist on the application of the technique for child brain examinations. PURPOSE: To explore the application of a 3D-pcASL perfusion MRI scan combined with postlabeling delay (PLD) for assessing neonatal hypoxic-ischemic encephalopathy (HIE). MATERIALS AND METHODS: Two-hundred neonates diagnosed with neonatal HIE were equally divided into five groups (40/group): 0- to <24-hour-old HIE group, 1- to <3-day-old HIE group, 3- to <7-day-old HIE group, 7- to <15-day-old HIE group and 15- to 28-day-old HIE group; 200 healthy neonates were equivalently divided. All 10 groups received a conventional and a 3D-pcASL perfusion MRI scan. For groups <3 days old, PLD values for the 3D-pcASL cerebral perfusion MRI scan were preset at 1025 ms; in all other groups, PLD values were preset at 1525 ms. CBF values for the 3D-pcASL cerebral perfusion MRI were compared between the HIE and corresponding control groups to determine the distinguishing characteristics of CBF values in HIE neonates. RESULTS: On the 3D-pcASL cerebral perfusion MRI scan, in the 1- to <3-day-old groups, HIE neonate CBF values were higher than those of controls in all brain regions (excluding the frontal lobe); in the 0- to <24-hour-old and 3- to <7-day-old groups, HIE neonate CBF values were lower than those of corresponding controls in all brain regions; in the 7- to <15-day-old and 15- to 28-day-old groups, there were no significant differences in the CBF values between groups in any brain regions. CONCLUSIONS: The 3D-pcASL perfusion MRI scan combined with a PLD can assist in the early diagnosis of neonatal HIE, as this method more comprehensively reflects the HIE pathological process.

Application of ASiR in combination with noise index in the chest CT examination of preschool-age children.

PURPOSE: To evaluate the application of adaptive statistical iterative reconstruction (ASIR) for chest CT scans of preschool-age children. METHOD: Sixty children, ages 0 to < 1, 1 to < 3, and 3 to < 6 years, who underwent CT non-contrast-enhanced and enhanced scans were included. The non-contrast-enhanced scan sequences were performed with noise indexes (NIs) of 11, 14, and 16 for the 0 to < 1, 1 to < 3, and 3 to < 6 year age groups, respectively. Collected data were reconstructed using ASIR in increments of 10%, ranging from 0 to 100%, to generate 11 image groups. The signal-to-noise ratio, image noise, and other features of images obtained using ASIR with different weights were compared and analyzed. The best weight ranges for ASIR of chest CT scans of children at different ages within the range of 0-6 years were obtained. Enhanced scan sequence: The NI default was 9, and the data were subjected to the filtered back projection reconstruction algorithm. All other scanning parameters were the same as those used in the non-contrast-enhanced scan sequence. RESULTS: In the 0 to < 1 year group, the image qualities were scored as 3 or above with ASIR weights of 50% for the lung window and 40% for the mediastinal window; in the 1 to < 3 year group, the image qualities were scored as 3 or above with ASIR weights of 60% for the lung window and 50% for the mediastinal window; in the 3 to < 6 year group, the image qualities were scored as 3 or above with ASIR weights of 70% for the lung window and 60% for the mediastinal window. CONCLUSION: For low-dose chest CT scans of preschool-age children, application of the ASIR technique significantly improved image quality and reduced image noise. The optimum weights of image ASIR were 50%, 60%, and 70% for the lung window and 40%, 50%, and 60% for the mediastinal window for the 0 to < 1, 1 to < 3, and 3 to < 6 year groups, respectively.