Search

Electroencephalographic (EEG) neurofeedback (NFB) is a popular neuromodulation method to help one selectively enhance or inhibit his/her brain activities by means of real-time visual or auditory feedback of EEG signals. Sensory motor rhythm (SMR) NFB protocol has been applied to improve cognitive performance, but a large proportion of participants failed to self-regulate their brain activities and could not benefit from NFB training. Therefore, it is important to identify the neural predictors of SMR up-regulation NFB training performance for a better understanding the mechanisms of individual difference in SMR NFB. Twenty-seven healthy participants (12 males, age: 23.1 ± 2.36) were enrolled to complete three sessions of SMR up-regulation NFB training and collection of multimodal neuroimaging data [resting-state EEG, structural magnetic resonance imaging (MRI), and resting-state functional MRI (fMRI)]. Correlation analyses were performed between within-session NFB learning index and anatomical and functional brain features extracted from multimodal neuroimaging data, in order to identify the neuroanatomical and neurophysiological predictors for NFB learning performance. Lastly, machine learning models were trained to predict NFB learning performance using features from each modality as well as multimodal features. According to our results, most participants were able to successfully increase the SMR power and the NFB learning performance was significantly correlated with a set of neuroimaging features, including resting-state EEG powers, gray/white matter volumes from MRI, regional and functional connectivity (FC) of resting-state fMRI. Importantly, results of prediction analysis indicate that NFB learning index can be better predicted using multimodal features compared with features of single modality. In conclusion, this study highlights the importance of multimodal neuroimaging technique as a tool to explain the individual difference in within-session NFB learning performance, and could provide a theoretical framework for early identification of individuals who cannot benefit from NFB training. [ABSTRACT FROM AUTHOR]

Objectives: To compare visualization of joint intracranial and carotid vessel walls between 5× compressed sensing accelerated three-dimensional DANTE-SPACE sequence (CS VWI) acquired in 5 min and the same sequence accelerated by 2.7× parallel imaging (PI VWI) which takes 9-10 min currently.Methods: Following institutional review board approval and informed consent, 28 subjects including 20 stroke patients underwent PI and CS VWI examinations with an acquired spatial resolution of isotropic 0.55 mm and joint coverage of intracranial and carotid arteries. Quantitative wall thickness measurements of CS VWI and PI VWI were compared on healthy volunteers and patients with wall thickening respectively. Subjective wall visualizations of the two VWI methods on patients were scored by two radiologists blindly and independently using a 4-point scale followed by inter-rater reproducibility analysis.Results: Linear regression analysis of wall thickness measurements showed excellent agreement between CS VWI and PI VWI in both healthy volunteers (r = 0.99) and stroke patients with wall thickening (r = 0.99). Subjective wall visualization score of CS VWI was slightly lower than PI VWI (3.13 ± 0.41 vs. 3.31 ± 0.79) but still had good diagnostic quality (> 3 based on a 4-point scale). The two radiologists' scores agreed excellently, evidenced by the intraclass correlation coefficient (ICC) values being higher than 0.75 (p < 0.001).Conclusions: Compressed sensing expedients joint intracranial and carotid VWI acquired at an isotropic resolution of 0.55 mm in 5 min without compromising quantitative vessel wall thickness measurement or diagnostic wall visualization.Key Points: • CS VWI facilitates comprehensive visualization of intracranial and carotid vessel walls at an acquired isotropic resolution of 0.55 mm in a single 5-min scan. • CS VWI affords comparable vessel wall visualization and morphology measurement as PI VWI with a shortened acquisition time by 45%. • CS VWI alleviates the intensive trade-off between imaging resolution and scan time, and benefits the scan efficiency, motion robustness, and patient tolerance of high-resolution joint intracranial and carotid VWI. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the clinical performance of a newly developed three-dimensional (3D) intra- and extracranial arterial vessel wall joint imaging technique at 3T using T1-weighted 3D variable-flip-angle turbo spin-echo sequence with improved cerebrospinal fluid suppression in patients with cerebrovascular disease.Materials and Methods: 122 consecutive patients (mean age 45.96 ± 12.16 years) with clinically confirmed cerebrovascular symptoms were imaged using a 3D intra- and extracranial arterial vessel wall joint imaging sequence with and without contrast enhancement on a 3 T MR system. The number of plaques and culprit plaques were evaluated. The image quality score, percent stenosis, remodeling ratio, and plaque burden were measured and compared between intracranial and carotid arterial plaques, and between non-culprit and culprit plaques.Results: Except for 23 patients, there were 322 plaques (111 culprit plaques) detected in 96 patients with large artery atherosclerosis. Of the plaques, 278 (96 culprit plaques) and 44 (15 culprit plaques) plaques were identified in intracranial and extracranial arteries, respectively. Image quality did not differ significantly between pre- and post-contrast vessel wall magnetic resonance images. There were also no significant differences in the percent stenosis, remodeling ratio, and plaque burden between intracranial and carotid arteries, and between non-culprit and culprit plaques. The enhancement rate of culprit plaques was significantly higher than that of non-culprit plaques.Conclusions: The described joint imaging is a promising vessel wall magnetic resonance imaging method for comprehensive diagnosis of cerebrovascular symptoms and investigation of etiology. The imaging technique is a potentially valuable means to optimize treatment. [ABSTRACT FROM AUTHOR]