Ali-Reza Mohammadi-Nejad

• PhD
• Research Fellow at University of Nottingham

Background Multimorbidity has been identified as a research priority in recent years, fibrosis (progressive organ scarring) is one mechanism which may underpin multimorbidity. Some studies suggest hypertension could be fibrotic, particularly severe hypertension (uncontrollable with medications), however it is not currently known whether severe hype...

The impact of SARS-CoV-2 and the COVID-19 pandemic on cognitive and mental health is recognised, yet specific effects on brain health remain understudied. We investigated the pandemics impact on brain ageing using longitudinal neuroimaging data from the UK Biobank. Brain age prediction models were trained from hundreds of multi-modal imaging featur...

Associations between datasets can be discovered through multivariate methods like Canonical Correlation Analysis (CCA) or Partial Least Squares (PLS). A requisite property for interpretability and generalizability of CCA/PLS associations is stability of their feature patterns. However, stability of CCA/PLS in high-dimensional datasets is questionab...

Background Idiopathic pulmonary fibrosis (IPF) is a serious disease of the lung parenchyma. It has a known polygenetic risk, with at least seventeen regions of the genome implicated to date. Growing evidence suggests linked multimorbidity of IPF with neurodegenerative or affective disorders. However, no study so far has explicitly explored links be...

The reciprocal interaction between pain and negative affect is acknowledged but pain‐related alterations in brain circuits involved in this interaction, such as the mediodorsal thalamus (MDThal), still require a better understanding. We sought to investigate the relationship between MDThal circuitry, negative affect and pain severity in chronic mus...

Background Type 2 diabetes mellitus impacts the brain microstructural environment. Diffusion tensor imaging (DTI) has been widely used to characterize white matter microstructural abnormalities in type 2 diabetes but fails to fully characterise disease effects on complex white matter tracts. Neurite orientation dispersion and density imaging (NODDI...

Background: Idiopathic pulmonary fibrosis (IPF) is a serious disease of the lung parenchyma. It has a known polygenetic risk, with at least seventeen regions of the genome implicated to date. Growing evidence suggests linked multimorbidity of IPF with neurodegenerative or affective disorders. However, no study so far has explicitly explored links b...

Objective Long-term opioid use is associated with diminished pain relief, hyperalgesia, and addiction which is not well understood. This study aimed to characterise opioid-related brain network alterations in chronic pain, focused on the right amygdala, and left mediodorsal thalamic nuclei that play key roles in affective pain processing, and are p...

Background and purpose: Anticholinergic (AC) medication use is associated with cognitive decline and dementia, which may be related to an AC-induced central hypocholinergic state, but the exact mechanisms remain to be understood. We aimed to further elucidate the putative link between AC drug prescription, cognition, and structural and functional...

While neuroimaging studies reveal that several brain regions may participate in multiple groups (networks), this group overlap is neglected in multi-modal data fusion frameworks. Indeed, it is not clear how much “information” is lost due to this negligence. To study this issue, we present a group-structured sparse canonical correlation analysis (gs...

Background Anticholinergic (AC) medication use is associated with cognitive decline and dementia, which may be related to an AC induced central hypocholinergic state, but the exact mechanisms remain to be understood. We aimed to further elucidate the putative link between AC drug prescription, cognition and structural and functional impairment of t...

Associations between high-dimensional datasets, each comprising many features, can be discovered through multivariate statistical methods, like Canonical Correlation Analysis (CCA) or Partial Least Squares (PLS). CCA and PLS are widely used methods which reveal which features carry the association. Despite the longevity and popularity of CCA/PLS ap...

Mapping connections in the neonatal brain can provide insight into the crucial early stages of neurodevelopment that shape brain organisation and lay the foundations for cognition and behaviour. Diffusion MRI and tractography provide unique opportunities for such explorations, through estimation of white matter bundles and brain connectivity. Atlas...

Mapping connections in the neonatal brain can provide insight into the crucial early stages of neurodevelopment that shape brain organisation and lay the foundations for cognition and behaviour. Diffusion MRI and tractography provide unique opportunities for such explorations, through estimation of white matter bundles and brain connectivity. Atlas...

Infancy is the most critical period in human brain development. Studies demonstrate that subtle brain abnormalities during this state of life may greatly affect the developmental processes of the newborn infants. One of the rapidly developing methods for early characterization of abnormal brain development is functional connectivity of the brain at...

Recent studies in the field of multi-modal data fusion demonstrate that considering the prior spatial structure and groupness information available from many years of intensive neuroimaging research can increase interpretability and detection accuracy of the hidden phenomena within multi-modal datasets. Although recent functional neuroimaging data...

Multi-modal data fusion has recently emerged as a comprehensive neuroimaging analysis approach, which usually uses canonical correlation analysis (CCA). However, the current CCA-based fusion approaches face problems like high-dimensionality, multi-collinearity, unimodal feature selection, asymmetry, and loss of spatial information in reshaping the...

Excessive yawning was described in some neurological conditions as part of periictal or ictal manifestations of epilepsy, most commonly temporal lobe. We present the first case of controllable yawning as a primary seizure semiology with dominant frontal lobe involvement in a 20-year-old man. Video electroencephalography recorded 8 yawning episodes...

Super-paramagnetic iron oxide (SPIO) nanoparticles are actively investigated to enhance disease detection through molecular imaging using magnetic resonance imaging (MRI). Detection of the cells labeled by SPIO depends on the MRI protocols and pulse sequence parameters that can be optimized. To evaluate the sensitivity and specificity of the image...

MRl simulation is a suitable method to evaluate and acquire understanding of the complex blood oxygenation level dependent (BOLD) effect. To study the observability of BOLD signal, we extended a MRI simulator. This simulator is capable of complete modeling of object (tissue) and main field inhomogeneities. We made a digital phantom in which the mag...

In this paper we simulated echo planar imaging (EPI) pulse sequence in 3D SIMRI simulator based on solution of the Bloch equation. The novelty of our work is the modification of simulator to simulate EPI which has a rectilinear trajectory in k-space. In this flexible simulation we assessed the effect of imaging speed (via number of excitations) on...

To evaluate the sensitivity and specificity of MR acquisition methods for molecular imaging, we extended a magnetic resonance imaging (MRI) simulator. This simulator is capable of complete modeling of object (tissue) in microscopic level to study the effect of spatial distribution and concentration of nanoparticles. Using this tool we studied gradi...