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Aims: To examine whether functional connectivity (FC) of the occipital gyrus differs between patients with Parkinson's disease (PD) motor subtypes and healthy controls (HCs). Methods: We enrolled 30 PD patients exhibiting tremor dominance (TD), 43 PD patients with postural instability and gait disturbance (PIGD), and 42 HCs. The occipital gyrus was partitioned into six areas of interest, as seed points, via the Anatomical Automatic Labeling template to compare the FC of the three groups and analyze the relationship of FC with clinical scales. Results: Compared with the PIGD group, the TD group showed increased FC between the left superior occipital gyrus (SOG.L) and right median cingulate and paracingulate gyri (DCG.R)/right paracentral lobule/bilateral inferior parietal, but supramarginal and angular gyri; the left middle occipital gyrus (MOG.L) and left posterior cingulate gyrus (PCG.L); the MOG.R and SOG.L/right calcarine fissure and surrounding cortex/DCG.R/PCG.L/right cuneus; the left inferior occipital gyrus (IOG.L) and right caudate nucleus; and the IOG.R and PCG.L. Conclusion: Differentiated FC between the occipital gyrus and other brain areas within the PD motor subtypes, which may serve as neural markers to distinguish between patients with TD and PIGD PD. [ABSTRACT FROM AUTHOR]

Background: Ultra‐high field 7T MRI can provide excellent tissue contrast and anatomical details, but is often cost prohibitive, and is not widely accessible in clinical practice. Purpose: To generate synthetic 7T images from widely acquired 3T images with deep learning and to evaluate the feasibility of this approach for brain imaging. Study Type: Prospective. Population: 33 healthy volunteers and 89 patients with brain diseases, divided into training, and evaluation datasets in the ratio 4:1. Sequence and Field Strength: T1‐weighted nonenhanced or contrast‐enhanced magnetization‐prepared rapid acquisition gradient‐echo sequence at both 3T and 7T. Assessment: A generative adversarial network (SynGAN) was developed to produce synthetic 7T images from 3T images as input. SynGAN training and evaluation were performed separately for nonenhanced and contrast‐enhanced paired acquisitions. Qualitative image quality of acquired 3T and 7T images and of synthesized 7T images was evaluated by three radiologists in terms of overall image quality, artifacts, sharpness, contrast, and visualization of vessel using 5‐point Likert scales. Statistical Tests: Wilcoxon signed rank tests to compare synthetic 7T images with acquired 7T and 3T images and intraclass correlation coefficients to evaluate interobserver variability. P < 0.05 was considered significant. Results: Of the 122 paired 3T and 7T MRI scans, 66 were acquired without contrast agent and 56 with contrast agent. The average time to generate synthetic images was ~11.4 msec per slice (2.95 sec per participant). The synthetic 7T images achieved significantly improved tissue contrast and sharpness in comparison to 3T images in both nonenhanced and contrast‐enhanced subgroups. Meanwhile, there was no significant difference between acquired 7T and synthetic 7T images in terms of all the evaluation criteria for both nonenhanced and contrast‐enhanced subgroups (P ≥ 0.180). Data Conclusion: The deep learning model has potential to generate synthetic 7T images with similar image quality to acquired 7T images. Level of Evidence: 2 Technical Efficacy: Stage 1 [ABSTRACT FROM AUTHOR]

Background: Magnetic resonance‐guided focused ultrasound (MRgFUS) thalamotomy has been implemented as a therapeutic alternative for the treatment of drug‐refractory essential tremor (ET). However, its impact on the brain structural network is still unclear. Purpose: To investigate both global and local alterations of the white matter (WM) connectivity network in ET after MRgFUS thalamotomy. Study Type: Retrospective. Subjects: Twenty‐seven ET patients (61 ± 11 years, 19 males) with MRgFUS thalamotomy and 28 healthy controls (HC) (61 ± 11 years, 20 males) were recruited for comparison. Field Strength/Sequence: A 3 T/single shell diffusion tensor imaging by using spin‐echo‐based echo‐planar imaging, three‐dimensional T1 weighted imaging by using gradient‐echo‐based sequence. Assessment: Patients were undergoing MRgFUS thalamotomy and their clinical data were collected from pre‐operation to 6‐month post‐operation. Network topological metrics, including rich‐club organization, small‐world, and efficiency properties were calculated. Correlation between the topological metrics and tremor scores in ET groups was also calculated to assess the role of neural remodeling in the brain. Statistical Tests: Two‐sample independent t‐tests, chi‐squared test, ANOVA, Bonferroni test, and Spearman's correlation. Statistical significance was set at P < 0.05. Results: For ET patients, the strength of rich‐club connection and clustering coefficient significantly increased vs. characteristic path length decreased at 6‐month post‐operation compared with pre‐operation. The distribution pattern of rich‐club regions was different in ET groups. Specifically, the order of the rich‐club regions was changed according to the network degree value after MRgFUS thalamotomy. Moreover, the altered nodal efficiency in the right temporal pole of the superior temporal gyrus (R = 0.434–0.596) and right putamen (R = 0.413–0.436) was positively correlated with different tremor improvement. Data Conclusion: These findings might improve understanding of treatment‐induced modulation from a network perspective and may work as an objective marker in the assessment of ET tremor control with MRgFUS thalamotomy. Level of Evidence: 3 Technical Efficacy: Stage 4 [ABSTRACT FROM AUTHOR]

This article discusses a case of Balamuthia mandrillaris encephalitis (BAE) in a 35-year-old male who consumed raw beef prior to experiencing symptoms. BAE is a rare and severe parasitic infection of the central nervous system with a high mortality rate. The clinical manifestations of BAE are nonspecific, making diagnosis challenging. Neuroimaging typically reveals multiple supratentorial and infratentorial lesions. Treatment guidelines for BAE are not well established, but a combination therapy using miltefosine, fluconazole, and pentamidine is often recommended. [Extracted from the article]

Aim: This study aimed to evaluate the diagnostic value of ultrahigh‐field magnetic resonance imaging (MRI) for brain tumors in clinical practice. Methods: Thirty patients with brain tumors underwent 7‐ and 3‐T MRI. The performance and diagnostic confidence of 7‐ and 3‐T MRI in the visualization of tumor details such as internal structure and feeding artery were evaluated by radiologists. Contrast‐enhanced region performance and tumor detail diagnostic confidence score (DCS) were calculated and compared between 7 and 3T using Wilcoxon rank sum test. Results: In 19 with obvious enhancement and 11 cases without obvious enhancement, 7‐ and 3‐T MRI showed similar performance. The tumors' internal structure and feeding artery were more clearly depicted by 7‐T MRI (62.2% and 54.4%, respectively) than by 3‐T MRI (2.2% and 6.7%, respectively). Furthermore, the mean DCSs of both internal structure and feeding artery were higher at 7T than at 3T (internal structure: 16.29 ± 9.67 vs. −5.79 ± 4.12, p = 0.028; feeding artery: 21.96 ± 6.93 vs. 4.46 ± 7.07, p = 0.028). The DCS was more significantly improved in the senior radiologist group. Conclusion: Better visualization of brain tumor details and higher tumor detail diagnostic confidence can be obtained with 7‐T MRI. [ABSTRACT FROM AUTHOR]

Objective: MRI-guided focused ultrasound (MRgFUS) thalamotomy is a novel and minimally invasive alternative for medication-refractory tremor in Parkinson's disease (PD). However, the impact of MRgFUS thalamotomy on spontaneous neuronal activity in PD remains unclear. The purpose of the current study was to evaluate the effects of MRgFUS thalamotomy on local fluctuations in neuronal activity as measured by the fractional amplitude of low-frequency fluctuations (fALFF) in patients with PD., Methods: Participants with PD undergoing MRgFUS thalamotomy were recruited. Tremor scores were assessed before and 3 and 12 months after treatment using the Clinical Rating Scale for Tremor. MRI data were collected before and 1 day, 1 week, 1 month, 3 months, and 12 months after thalamotomy. The fALFF was calculated. A whole-brain voxel-wise paired t-test was used to identify significant changes in fALFF at 12 months after treatment compared to baseline. Then fALFF in the regions with significant differences were extracted from fALFF maps of patients for further one-way repeated-measures ANOVA to investigate its dynamic alterations. The association between fALFF changes induced by thalamotomy and tremor improvement were evaluated using the nonparametric Spearman rank test., Results: Nine participants with PD (mean age ± SD 64.7 ± 6.1 years, 8 males) were evaluated. Voxel-based analysis showed that fALFF in the left occipital cortex (Brodmann area 17 [BA17]) significantly decreased at 12 months after thalamotomy compared to baseline (voxel p < 0.001, cluster p < 0.05 family-wise error [FWE] corrected). At baseline, fALFF in the left occipital BA17 in patients was elevated compared with that in 9 age- and gender-matched healthy subjects (p < 0.05). Longitudinal analysis displayed the dynamic changes of fALFF in this region (F (5,40) = 3.61, p = 0.009). There was a significant positive correlation between the falling trend in fALFF in the left occipital BA17 and hand tremor improvement after treatment over 3 time points (Spearman's rho = 0.44, p = 0.02)., Conclusions: The present study investigated the impact of MRgFUS ventral intermediate nucleus thalamotomy on spontaneous neural activity in medication-refractory tremor-dominant PD. The visual area is, for the first time, reported as relevant to tremor improvement in PD after MRgFUS thalamotomy, suggesting a distant effect of MRgFUS thalamotomy and the involvement of specific visuomotor networks in tremor control in PD.