The poor SNR of fMRI data requires that many repetitive trials be performed during an event-related experiment to obtain statistically significant levels of inferred brain activity. This is costly in terms of scanner time, necessitates that subjects perform the behavioural task(s) for long durations which may induce fatigue, and vastly increases the amount of data generated. In this paper, we present a method to enhance the statistical effect size using ICA, so that the same level of significance can be obtained with shorter scanning times. We perform ICA on fMRI data from a simple event-related motor task by projecting the original data onto the linear subspace defined by the task-related ICA components. This essentially denoises the signal and results in significant improvement in the effect size. Using simulations we demonstrate that the proposed ICA-denoising procedure is robust to a variety of realistic noise models and enhances the performance of least squares estimates of the evoked hemodynamic response.
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http://dx.doi.org/10.1109/IEMBS.2005.1616366 | DOI Listing |
Background: Hypothyroidism is a common sequela after radiotherapy for nasopharyngeal carcinoma (NPC). Magnetic resonance imaging (MRI) has gained prominence in thyroid imaging, leveraging its non-ionizing radiation, high spatial resolution, multiparameter and multidirectional imaging. Few previous studies have investigated the evaluation of radiation-induced thyroid injury by MRI.
View Article and Find Full Text PDFFront Neural Circuits
January 2025
Department of Advanced Medical and Surgical Sciences, Advanced MRI Research Center, University of Campania "Luigi Vanvitelli", Naples, Italy.
The substantia nigra pars compacta (SNc), one of the main dopaminergic nuclei of the brain, exerts a regulatory function on the basal ganglia circuitry via the nigro-striatal pathway but its possible dopaminergic innervation of the thalamus has been only investigated in non-human primates. The impossibility of tract-tracing studies in humans has boosted advanced MRI techniques and multi-shell high-angular resolution diffusion MRI (MS-HARDI) has promised to shed more light on the structural connectivity of subcortical structures. Here, we estimated the possible dopaminergic innervation of the human thalamus via an MS-HARDI tractography of the SNc in healthy human young adults.
View Article and Find Full Text PDFFront Oncol
January 2025
Medical Imaging Center, The First Hospital of Kunming, Kunming, China.
Objective: The invasiveness of pituitary neuroendocrine tumor is an important basis for formulating individualized treatment plans and improving the prognosis of patients. Radiomics can predict invasiveness preoperatively. To investigate the value of multiparameter magnetic resonance imaging (mpMRI) radiomics in predicting pituitary neuroendocrine tumor invasion into the cavernous sinus (CS) before surgery.
View Article and Find Full Text PDFFront Aging Neurosci
January 2025
Department of Neurology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.
Introduction: Cerebral small vessel disease (CSVD) is a chronic systemic degenerative disease affecting small blood vessels in the brain, leading to cognitive impairments. Transcranial direct current stimulation (tDCS), a non-invasive brain stimulation technique that applies low electrical currents to the scalp, shows promise in treating cognitive and movement disorders. However, further clinical evaluation is required to assess the long-term effects of tDCS on neuroplasticity and gait in patients with CSVD.
View Article and Find Full Text PDFObjective: Cervical degeneration involves many pathophysiological changes. Vertebral bone loss, sclerotic hyperplasia of the vertebral body and intervertebral disc degeneration (IDD) are most common degenerative factors. However, whether there is a correlation between changes in vertebral bone mass and IDD remains unclear.
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