Altered dynamic and static brain activity and functional connectivity in COVID-19 patients: a preliminary study.

This study aimed to investigate the effects of COVID-19 on brain functional activity through resting-state functional MRI (rs-fMRI). fMRI scans were conducted on a cohort of 42 confirmed COVID-19-positive patients and 46 healthy controls (HCs) to assess brain functional activity. A combination of dynamic and static amplitude of low-frequency fluctuations (dALFF/sALFF) and dynamic and static functional connectivity (dFC/sFC) was used for evaluation. Abnormal brain regions identified were then used as feature inputs in the model to evaluate support vector machine (SVM) capability in recognizing COVID-19 patients. Moreover, the random forest (RF) model was employed to verify the stability of SVM diagnoses for COVID-19 patients. Compared to HCs, COVID-19 patients exhibited a decrease in sALFF in the right lingual gyrus and the left medial occipital gyrus and an increase in dALFF in the right straight gyrus. Moreover, there was a decline in sFC between both lingual gyri and the right superior occipital gyrus and a reduction in dFC with the precentral gyrus. The dynamic and static combined ALFF and FC could distinguish between COVID-19 patients and the HCs with an accuracy of 0.885, a specificity of 0.818, a sensitivity of 0.933 and an area under the curve of 0.909. The combination of dynamic and static ALFF and FC can provide information for detecting brain functional abnormalities in COVID-19 patients.

Amide proton transfer imaging in rats after heatstroke.

Metabolic acidosis is the most common acid-base change following heatstroke. This study aimed to evaluate the internal environment changes caused by heatstroke using amide proton transfer (APT) imaging. Nineteen male Sprague-Dawley rats were randomly divided into the control group (CTRL, n  = 7) and the heatstroke group (HS, n  = 12). All the rats underwent a 7.0-T MRI, which included T2-weighted imaging (T2WI) and APT imaging. Subsequently, the surviving HS group rats repeated the same magnetic resonance scanning after 25 days and were designated as the follow-up group (FU, n  = 7). APT values were measured in the hippocampus, thalamus, and corpus callosum. The APT values of the three groups were statistically analyzed and found in the hippocampus (CTRL vs. HS, P  = 0.011; CTRL vs. FU, P  = 0.078; HS vs. FU, P  = 0.484; η ² = 0.276), left thalamus (CTRL vs. HS, P  = 0.004; CTRL vs. FU, P  = 0.014; HS vs. FU, P  = 0.822; η ² = 0.331), right thalamus (CTRL vs. HS, P  = 0.003; CTRL vs. FU, P  = 0.015; HS vs. FU P  = 0.769; η ² = 0.336), and corpus callosum (CTRL vs. HS, P  < 0.001; CTRL vs. FU, P  = 0.005; HS vs. FU, P  = 0.523; η ² = 0.437). APT imaging can be a viable and practical tool for diagnosing heatstroke and monitoring its progression.

Application of diffusion tensor imaging and functional alterations in evaluating brain alterations related to heatstroke in a rat model.

OBJECTIVES: To assess the alterations in resting-state functions and neural structures in the brain of a heatstroke rat model and explore the underlying relationship. METHODS: In total, 17 male Sprague Dawley rats were randomly divided into a control group (CTRL, n = 7) and a heatstroke group (HS, n = 10). All rats underwent 7.0 T magnetic resonance imaging (MRI). T2-weighted imaging, resting-state functional MRI (rs-fMRI), and diffusion tensor imaging (DTI) were obtained. On day 25, the surviving HS group rats (the follow-up group, FU, n = 7) were scanned again. RESULTS: Heatstroke resulted in functional alterations and structural damage in the cerebellar molecular layer (CML), right perirhinal area (PA), pretectal region (PR), right dentate gyrus, and external cortex of the inferior colliculus (ECIC). Further functional changes occur in the right temporal associative cortex (TAC), left retrosplenial cortex (RC), and CML during convalescence. The fractional anisotropy values were significantly positively correlated with the amplitude of low-frequency fluctuation (ALFF) (HS-CML: r = 0.746, p = 0.034; right PR: r = 0.648, p = 0.049; FU-right PA: r = 0.817, p = 0.025)/regional homogeneity (ReHo) ratio (HS-CML: r = 0.833, p = 0.008; ECIC: r = 0.678, p = 0.045) and negatively correlated with the ALFF (FU-left RC: r = -0.818, p = 0.024; right TAC: r = -0.813, p = 0.049). CONCLUSION: DTI and rs-fMRI allow meticulous monitoring of the progression of neurological and functional alterations in the brain after heatstroke.

TBSS analysis of white matter fasciculus in chronic insomnia and the relationship with sleep quality and cognitive function.

Eighty patients with chronic insomnia and 50 normal controls were selected. Evaluation scales included Pittsburgh Sleep Quality Index, Dysfunctional Beliefs and Attitudes about Sleep, Montreal Cognitive Assessment, Self-Rating Anxiety Scale, Self-Rating Depression Scale, Ruminative Responses Scale and Social Disability Screening Schedule. All patients and controls underwent whole-brain DTI scanning and Tract-Based Spatial Statistics (TBSS) analysis was performed. Chronic insomnia patients are mainly accompanied by white matter lesions of right posterior thalamic radiation, right sagittal tract, and right upper longitudinal tract. TBSS is helpful in the diagnosis of chronic insomnia and can reflect the changes of cognitive function.

MR features of high-pressure injection injuries caused by grease and paints.

OBJECTIVE: This study investigates the magnetic resonance (MR) features of high-pressure injection injuries (HPII) caused by grease and paints to detect the presence of foreign material and associated complications. METHODS: Sixteen rat models with HPII were established by injecting industrial grease and marine paints (n = 8 each) into their thighs. All the rats underwent a 3.0 T MR scanning, including T1-weighted imaging (T1WI), T2-weighted imaging (T2WI), Fat-suppressed T2-weighted imaging (FST2WI), Susceptibility-weighted imaging (SWI), and Diffusion-weighted imaging (DWI). Follow-up MR scanning was performed from 1st to 4th weeks. RESULTS: Acute subcutaneous grease and paints appeared as different signal intensity characteristics (grease: T1WI ↑, T2WI =, FST2WI ↓, SWI ↓, DWI ↓; paints: T1WI ↑, T2WI ↑, FST2WI ↑↓, SWI ↓, DWI ↓). As time progressed, the signal intensity of HPII lesions caused by both grease and paints became inhomogeneous. Impurity components of the foreign material appeared as marked low signal intensity on SWI. The signal intensity on DWI significantly increased subsequently due to purulent fluids (confirmed surgically). CONCLUSIONS: HPII caused by grease and paints have a characteristic appearance on MR imaging. SWI can detect impurity components of the foreign material, while DWI is highly sensitive to abscesses and helpful in monitoring infections.

Magnetic compression for anastomosis in treating an infant born with long-gap oesophageal atresia: A case report.

RATIONALE: Neonatal long-gap esophageal atresia (LGEA) with tracheoesophageal fistula (TEF) is an uncommon but serious congenital malformation of the esophagus in newborns, and it remains challenging for pediatric surgeons. Magnetic compress has been shown to be effective for the treatment of LGEA in children and adults. However, the implementation of this unique technique for neonatal LGEA has not been evaluated. PATIENT CONCERNS: A female infant was born at 37 weeks of gestation. Prenatal ultrasound imaging revealed signs of esophageal atresia, including the absence of the gastric bubble and polyhydramnios. DIAGNOSES: A diagnosis of LGEA with TEF was confirmed at birth by contrast X-ray. INTERVENTIONS: She was treated with magnetic compression anastomosis (MCA) following an esophago-esophagostomy. Two magnetic rings were customized, and the MCA was conducted during the same stage surgery of ligating the TEF. Under the magnetic force, the 2 magnet rings pulled along the gastric tube to achieve anastomosis. The postoperative permanent suction of these 2 pouches was instituted, and spontaneous growth was awaited. Magnet removal was performed at 36 days, and enteral nutrition was continued via a gastric tube for 4 weeks at post-operation. OUTCOMES: The upper gastrointestinal contrast confirmed the anastomotic patency perfectly after 3 months. The patient was followed up for 18 months, and exhibited durable esophageal patency without dysphagia. LESSONS: These results suggest that MCA is feasible and effective for treating LGEA in infants.