Altered Brain Glymphatic Function at Diffusion-Tensor MRI in Pre-cirrhotic Metabolic Dysfunction-Associated Fatty Liver Disease.

RATIONALE AND OBJECTIVES: To evaluate glymphatic function changes and their relationships with clinical features in patients with metabolic dysfunction-associated fatty liver disease (MAFLD), thereby facilitating early intervention before this disease progresses to cirrhosis. MATERIALS AND METHODS: A cross-sectional cohort of 46 pre-cirrhotic MAFLD patients and 30 age-, sex-, and education-matched controls was enrolled, with diffusion-tensor imaging (DTI) data, laboratory and neurocognitive scores collected. The DTI analysis along the perivascular space (DTI-ALPS) index was computed for qualifying glymphatic function. Generalized linear model and partial correlation analyses were applied to evaluate relationships between the ALPS index and clinical variables. RESULTS: MAFLD group exhibited a decreased ALPS index and increased diffusivity along the y-axis in the projection fiber compared to the controls. The altered ALPS index was associated with clock drawing test (CDT) score (3.931 [0.914, 6.947], P = 0.011) and was correlated with diastolic pressure level (r = -0.315, P = 0.033) in MAFLD group. The relationships of ALPS index with CDT score (6.263 [2.069, 10.458], P = 0.003) and diastolic pressure level (r = -0.518, P = 0.014) remained in the MAFLD with metabolic syndrome (MetS) group. Furthermore, the ALPS index was even associated with Auditory Verbal Learning Test-Immediate recall score (-23.853 [-45.417, -2.289], P = 0.030) in MAFLD with MetS group. CONCLUSION: MAFLD patients may have a glymphatic dysfunction prior to cirrhosis, and this alteration may be related to cognition and diastolic pressure. Glymphatic dysfunction has a more severe impact on cognition when MAFLD patient is accompanied by MetS.

Abnormalities in spontaneous brain activity and functional connectivity are associated with cognitive impairments in children with type 1 diabetes mellitus.

BACKGROUND: It remains unclear whether alterations in brain function occur in the early stage of pediatric type 1 diabetes mellitus(T1DM). We aimed to examine changes in spontaneous brain activity and functional connectivity (FC) in children with T1DM using resting-state functional magnetic resonance imaging (rs-fMRI), and to pinpoint potential links between neural changes and cognitive performance. METHODS: In this study, 22 T1DM children and 21 age-, sex-matched healthy controls underwent rs-fMRI. The amplitude of low frequency fluctuations (ALFF) and seed-based FC analysis were performed to examine changes in intrinsic brain activity and functional networks in T1DM children. Partial correlation analyses were utilized to explore the correlations between ALFF values and clinical parameters. RESULTS: The ALFF values were significantly lower in the lingual gyrus (LG) and higher in the left medial superior frontal gyrus (MSFG) in T1DM children compared to controls. Subsequent FC analysis indicated that the LG had decreased FC with bilateral inferior occipital gyrus, and the left MSFG had decreased FC with right precentral gyrus, right inferior parietal gyrus and right postcentral gyrus in children with T1DM. The ALFF values of LG were positively correlated with full-scale intelligence quotient and age at disease onset in T1DM children, while the ALFF values of left MSFG were positively correlated with working memory scores. CONCLUSION: Our findings revealed abnormal spontaneous activity and FC in brain regions related to visual, memory, default mode network, and sensorimotor network in the early stage of T1DM children, which may aid in further understanding the mechanisms underlying T1DM-associated cognitive dysfunction.

A Novel Score Based on Controlled Attenuation Parameter Accurately Predicts Hepatic Steatosis in Individuals With Metabolic Dysfunction Associated Steatotic Liver Disease: A Derivation and Independent Validation Study.

INTRODUCTION: In metabolic dysfunction-associated steatotic liver disease, the diagnostic efficacy of controlled attenuation parameter (CAP) was not very accurate in evaluating liver fat content. The aim of this study was to develop a score, based on CAP and conventional clinical parameters, to improve the diagnostic performance of CAP regarding liver fat content. METHODS: A total of 373 participants from 2 independent Chinese cohorts were included and divided into derivation (n = 191), internal validation (n = 75), and external validation (n = 107) cohorts. Based on the significant difference index between the 2 groups defined by the magnetic resonance imaging-proton density fat fraction (MRI-PDFF) in derivation cohort, the optimal model (CAP-BMI-AST score [CBST]) was screened by the number of parameters and the area under the receiver operating characteristic curve (AUROC). In the internal and external validation cohorts, the AUROC and corresponding 95% confidence intervals (CIs) were used to compare the diagnostic performance of CBST with that of CAP. RESULTS: We constructed the CBST = -14.27962 + 0.05431 × CAP - 0.14266 × body mass index + 0.01715 × aspartate aminotransferase. When MRI-PDFF was ≥20%, ≥10%, and ≥5%, the AUROC for CBST was 0.77 (95% CI 0.70-0.83), 0.89 (95% CI 0.83-0.94), and 0.93 (95% CI 0.88-0.98), which was higher than that for CAP respectively. In the internal validation cohort, the AUROC for CBST was 0.80 (95% CI 0.70-0.90), 0.95 (95% CI 0.91-1.00), and 0.98 (95% CI 0.94-1.00). The optimal thresholds of CBST were -0.5345, -1.7404, and -1.9959 for detecting MRI-PDFF ≥20%, ≥10%, and ≥5%, respectively. DISCUSSION: The CBST score can accurately evaluate liver steatosis and is superior to the CAP.

[The effect of low-magnitude high-frequency loading on peri-implant bone healing and implant osseointegration in Beagle dogs].

PURPOSE: Low-magnitude, high-frequency（LMHF） loading has been confirmed to play an important role in bone healing. The present study aimed to evaluate the effect of LMHF loading applied directly to titanium dental implants on peri-implant bone healing and implant. METHODS: The mandibular premolars and molars were extracted from six male Beagle dogs. Three months post-extraction, six titanium implants (Aadva Standard Implant Narrow, 3.3 mm×8 mm) were inserted into the mandibular premolar and molar area (three implants per side) in each of the six dogs. In each animal, one side was randomly selected to undergo daily LMHF loading (experimental group), while the other side had no further intervention (control group). The loading was applied directly to the implant abutment using an individual jig and a custom-made loading device (8 µm,100 Hz). The implant stability quotient (ISQ) was tested every week. Three dogs were euthanized after 2 weeks, and three were euthanized after 8 weeks. Tissue samples were fixed and stained for micro-computed tomography(micro-CT) and histomorphometric analyses. The data were statistically analyzed using SPSS 13.0 software package. RESULTS: The experimental group had significantly increased peri-implant bone volume relative to tissue volume in region of interest 2 (100-500 µm) compared with the control group after 2 weeks of loading (P<0.05); however, there was no significant difference between the two groups after 8 weeks (P>0.05). The ISQ value and the micro-CT results did not differ between the two groups during the study period. CONCLUSIONS: LMHF loading positively influences peri-implant bone healing and osseointegration in the early healing period.

[Relationship between gestational age and apparent diffusion coefficient values in different regions of fetal brain from middle to late trimester].

OBJECTIVE: To analyze the relationship between gestational age and apparent diffusion coefficient (ADC) values in different regions of fetal brain from middle to late trimester. METHODS: DW images performed in 70 singleton non-sedated fetuses with questionably abnormal results on sonography and normal fetal MR imaging results were retrospectively reviewed. The median gestational age was 32.4 weeks (range, 24-38).With the formula of ADC = ln (S600/S0)/(B0-B600), the mean ADC values were obtained for fetal parietal white matter (WM), frontal WM, temporal WM, occipital WM, pons, cerebellum, basal ganglia and thalamus. The relationship of mean ADC values in different regions with gestational age was analyzed with linear regression. RESULTS: The mean ADC values were 1.77 ± 0.32 mm(2)/s (SD) in fetal parietal white matter (WM), 1.71 ± 0.32 mm(2)/s in occipital WM, 1.31 ± 0.18 mm(2)/s in thalamus, 1.34 ± 0.15 mm(2)/s in basal ganglia. And the mean ADC values in cerebellum, pons, frontal WM and temporal WM were 1.17 ± 0.16, 1.41 ± 0.18, 1.87 ± 0.18 and 1.74 ± 0.19 mm(2)/s respectively. A significant negative correlation between ADC values and gestational age was found for parietal WM, occipital WM, pons, cerebellum, basal ganglia and thalamus (P < 0.05). Frontal WM ADC (P > 0.05) and temporal WM ADC (P = 0.05) did not significantly change with gestational age whereas only a downward trend was present. The correlation coefficient (r) and coefficient of regression (b) were 0.420 and -0.045 in parietal WM; 0.470 and -0.052 in occipital WM; 0.370 and -0.027 in cerebellum; 0.027 and -0.020 in pons; 0.320 and -0.027 in thalamus; 0.300 and -0.021 in basal ganglia. The mean ADC values peaked in frontal WM and lowest in pons. The mean ADC values in white matter were higher than those in deep gray nuclei, cerebellum and pons.With the development of fetal brain,ADC values declined the fastest in cerebellum and occipital WM, followed by basal ganglia and thalamus. CONCLUSION: Regional differences in non-sedated fetal brain ADC values and their evolutions with gestational age are likely to reflect variations in brain maturation.

Neurochemical changes in the rat occipital cortex and hippocampus after repetitive and profound hypoglycemia during the neonatal period: an ex vivo ¹H magnetic resonance spectroscopy study.

The brain of a human neonate is more vulnerable to hypoglycemia than that of pediatric and adult patients. Repetitive and profound hypoglycemia during the neonatal period (RPHN) causes brain damage and leads to severe neurologic sequelae. Ex vivo high-resolution (1)H nuclear magnetic resonance (NMR) spectroscopy was carried out in the present study to detect metabolite alterations in newborn and adolescent rats and investigate the effects of RPHN on their occipital cortex and hippocampus. Results showed that RPHN induces significant changes in a number of cerebral metabolites, and such changes are region-specific. Among the 16 metabolites detected by ex vivo (1)H NMR, RPHN significantly increased the levels of creatine, glutamate, glutamine, γ-aminobutyric acid, and aspartate, as well as other metabolites, including succine, taurine, and myo-inositol, in the occipital cortex of neonatal rats compared with the control. By contrast, changes in these neurochemicals were not significant in the hippocampus of neonatal rats. When the rats had developed into adolescence, the changes above were maintained and the levels of other metabolites, including lactate, N-acetyl aspartate, alanine, choline, glycine, acetate, and ascorbate, increased in the occipital cortex. By contrast, most of these metabolites were reduced in the hippocampus. These metabolic changes suggest that complementary mechanisms exist between these two brain areas. RPHN appears to affect occipital cortex and hippocampal activities, neurotransmitter transition, energy metabolism, and other metabolic equilibria in newborn rats; these effects are further aggravated when the newborn rats develop into adolescence. Changes in the metabolism of neurotransmitter system may be an adaptive measure of the central nervous system in response to RPHN.

[Neurologic complications in children with enterovirus 71-infected hand-foot-mouth disease : clinical features, MRI findings and follow-up study].

OBJECTIVE: To explore the clinical and magnetic resonance imaging (MRI) characteristics and the follow-up outcomes of neurologic complications in children with enterovirus 71-infected hand-foot-mouth disease. METHODS: The clinical and MRI manifestations and follow-up outcomes in 35 children, at Second Affiliated Hospital, Wenzhou Medical College from August 2008 to November 2010, hospitalized with neurologic complications of enterovirus 71-infected hand-foot-mouth disease were retrospectively analyzed. RESULTS: Six children with aseptic meningitis presented the clinical symptoms and signs of meningitis. Five of them showed subdural effusion and ventriculomegaly, or both on MRI. At follow-ups, neurologic sequel could not be found. Among 24 cases with brainstem encephalitis, there were myoclonic jerks and tremor, ataxia, or both (grade I disease, n = 12), myoclonus and cranial-nerve involvement (grade II disease, n = 4), and cardiopulmonary failure after brain-stem infection (grade III disease, n = 8). In patients with brainstem encephalitis, lesions were predominantly located at the posterior portions of medulla and pons with hypointensity on T1WI and hyperintensity on T2WI. Cerebellar dentate nucleus, caudate nucleus and lenticular nucleus could also be involved. At follow-ups, the patients with mild symptoms had no neurologic sequel and the lesions within brain stem became small or vanished in most cases. While in the majority of serious patients, neurologic sequel could be found and the lesions located at brain stem became encephalomalacia. Fourteen cases with acute flaccid paralysis presented acute limb myasthenia with tendon reflex and muscular tension decreased. On spinal MRI, the lesions predominantly involved anterior horn regions of spinal cord with hypointensity on T1WI and hyperintensity on T2WI. Most patients improved their muscle strength and most lesions of spinal cord became smaller or vanished during follow-ups. CONCLUSION: MRI is the most effective modality of diagnosis and follow-up for neurologic complications in children with enterovirus 71-infected hand-foot-mouth disease. On MRI, the lesions mainly involve the anterior horn of spinal cord, medulla oblongata and pons. At follow-ups, most patients have no neurologic sequel and the visualized lesions will be absorbed after active treatment.

[Magnetic resonance imaging and spectroscopy of the bone marrow in children with common hematological diseases].

OBJECTIVE: To evaluate the magnetic resonance (MR) imaging and proton magnetic resonance spectroscopy ((1)H-MRS) in the diagnoses of pediatric hematological diseases. METHODS: A total of 35 cases with pediatric hematological diseases were confirmed by bone marrow puncturing. There were acute leukemia (n = 26), aplastic anemia (n = 6), thalassemia (n = 2) and autoimmune hemolytic anemia (n = 1). Thirty age-marched healthy children underwent MR imaging (T(1)WI, T(2)WI, STIR) and (1)H-MRS of lumber spine and ilium. The lumber spines and iliums were studied by observation of MR imaging and calculation of fat fraction (FF%). RESULTS: Two patterns were classified by MR imaging and (1)H-MRS in lumber spines and iliums of all cases. Pattern 1: hyperplasia of bone marrow (BM). There were acute leukemia (n = 26), thalassemia (n = 2) and autoimmune hemolytic anemia (n = 1). The manifestations included homogeneous low signal intensity (SI) on T(1)WI, homogeneous low SI on T(2)WI, high SI on STIR and high water peak and low fat peak on (1)H-MRS. The FF%s of Regions of Interest (ROI) in lumber 4s and left iliums of 26 cases with acute leukemia were 0%, of 3 cases with thalassemia or autoimmune hemolytic anemia were 5.02% and 3.70%. Pattern 2: inhibition of BM. There were 6 cases of aplastic anemia. The manifestations included homogeneous or inhomogeneous high SI on T(1)WI and T(2)WI, homogeneous or inhomogeneous low SI on STIR, and low water peak and high fat peak on (1)H-MRS. FF%s of ROI in lumber 4s and left iliums for 6 cases of aplastic anemia were 74.69% and 91.51%. FF% in all groups had significant differences according to the Mann-Whitney test (P < 0.05). CONCLUSIONS: MR imaging and (1)H-MRS may serve as a noninvasive method for checking hematopoietic status of bone marrow in pediatric hematological diseases.

A comparative study of axis-line-distance technique and Cobb method on assessing the curative effect on scoliosis.

PURPOSE: To compare the axis-line-distance technique (ALDT) and Cobb method for therapeutic evaluation of scoliosis. METHODS: Fifty-seven patients with scoliosis were treated in our hospital, 47 underwent conservative bracing therapy and 10 underwent surgery. Based on 171 full-spine X-ray images obtained from these 57 cases before treatment, during conservative treatment or surgery, and at final follow-up after removing the brace or after surgery, two radiologists independently measured and calculated the correction rate during treatment and at final follow-up and the rate of correction loss after treatment with the ALDT and Cobb methods. Paired t-test and correlation analysis were performed. RESULTS: Based on the ALDT, the lateral deviations of the apical vertebrae before treatment, during treatment, and at final follow-up were 31 ± 14 mm, 16 ± 8 mm, and 20 ± 8 mm, respectively; the correction rates during treatment and at final follow-up were 48.7 ± 21.2% and 37.6 ± 14.2%, respectively, and the rate of correction loss after treatment was 11.3 ± 6.5%. The Cobb angles of scoliosis before treatment, during treatment, and at final follow-up were 34 ± 14°, 19 ± 7°, and 22 ± 6°, respectively; the correction rates during treatment and at final follow-up were 44.4 ± 17.3% and 33.9 ± 14.4%, respectively, and the rate of correction loss after treatment was 11.4 ± 4.3%. Calculation of the correction rate during treatment differed significantly between the two radiologists when using the Cobb method (P < 0.05); their calculations of the correction rate and rate of correction loss were not different (P > 0.05). The measurement data of the two radiologists using the Cobb method showed a weak to moderate correlation (r = 0.49, 0.57, and 0.51, respectively). When using the ALDT, there were no significant differences between the radiologists in their measurements of the correction rate during and after treatment (P > 0.05) or in the rate of correction loss. The measurement data of the two radiologists using the ALDT showed a good to excellent correlation (r = 0.92, 0.93, and 0.90, respectively). CONCLUSION: The ALDT is better than the Cobb method for therapeutic evaluation of scoliosis during treatment and at follow-up visits.

Accuracy and repeatability of a new method for measuring scoliosis curvature.

STUDY DESIGN: A prospective diagnostic clinical trial. OBJECTIVE: To evaluate the accuracy, repeatability of a new method for measuring spinal curvature in patients with scoliosis, the axis-line-distance technique (ALDT), in comparison with the Cobb method. SUMMARY OF BACKGROUND DATA: Timely and accurate determination of the degree of lateral curvature of the spine is essential for deciding the appropriate treatment method for scoliosis. Although the Cobb method has been accepted as the clinical standard for 60 years, many investigators have reported a high degree of variance in the measurements of spinal curvature obtained using this method. Therefore, the development of an alternative method that incorporates the advances in imaging technology and assessment is needed. METHODS: Sixty-five scoliosis patients were evaluated by 6 physician observers. The spinal curves were measured on 2 separate occasions using the Cobb method and the ALDT on a picture archiving and communication system workstation. The time interval between the 2 measurements was 3 weeks, and the data were analyzed by a paired-sample Student t test and Pearson correlation method using SPSS 12.0 software package. RESULTS: Intraobserver variance of the 2 measurements, the minimum variance, the maximum variance, and the mean and standard deviation values were 0 degrees, 26 degrees, and 5.14 degrees +/- 0.69 degrees for the Cobb method, and 0 mm, 20 mm, and 2.55 +/- 0.38 mm for the ALDT, respectively. There was a significant intraobserver difference in the Cobb angle measurements among 3 of the 6 observers (P < 0.05). No significant intraobserver variance in ALDT measurements was detected. The mean interobserver measurement variance for the Cobb method was 6.54 degrees +/- 1.35 degrees, significantly greater than that for the ALDT (3.58 +/- 0.93 mm; P < 0.05). There were significant positive correlation between the ALDT and the Cobb measurements (r = 0.73, P < 0.05). CONCLUSION: The ALDT is more reliable, reproducible, and straightforward, and less error-prone than the Cobb method for measurements of spinal curvature.