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Several neuropsychiatric disorders involving hippocampal structural changes have been studied extensively using volumetric magnetic resonance imaging (MRI). These studies have mostly measured total hippocampal volume while the present study aimed to delineate and measure hippocampal subfields within the whole hippocampus and subdivisions along its(More)
PURPOSE To investigate the relationship between magnetic resonance (MR) imaging markers of iron content and disease severity in patients with multiple sclerosis (MS) over a 2-year period. MATERIALS AND METHODS This prospective study was approved by the local ethics committee, and written informed consent was obtained from all participants. Seventeen(More)
BACKGROUND Magnetic resonance imaging (MRI) has shown lower hippocampal volume in major depressive disorder (MDD). Preclinical and postmortem studies show that chronic stress and MDD may affect hippocampal subfields differently, but MRI spatial resolution has previously been insufficient to measure subfield volumes. METHODS Twenty MDD participants (9(More)
High risk behaviors such as narcotic use or physical fighting can be caused by impulsive decision making in emotionally-charged situations. Improved neuroscientific understanding of how emotional context interacts with the control of impulsive behaviors may lead to advances in public policy and/or treatment approaches for high risk groups, including some(More)
PURPOSE To investigate the relationship between iron staining and magnetic resonance (MR) imaging measurements in postmortem subjects with multiple sclerosis (MS). MATERIALS AND METHODS Institutional ethical approval was obtained, and informed consent was obtained from the subjects and/or their families. Four MR imaging methods based on transverse(More)
Presented is a fitting model for transverse relaxometry data acquired with the multiple-refocused spin-echo sequence. The proposed model, requiring no additional data input or pulse sequence modifications, compensates for imperfections in the transmit field and radiofrequency (RF) profiles. Exploiting oscillatory echo behavior to estimate alternate(More)
BACKGROUND In addition to neuronal injury, inflammatory, and demyelinating processes, evidence suggests multiple sclerosis (MS) is also associated with increased iron deposition in the basal ganglia. Magnetic resonance imaging (MRI), particularly at very high field strengths, is sensitive to iron accumulation and may enable visualization and quantification(More)
Transverse relaxation (T2 ) mapping has many applications, including imaging of iron accumulation in grey matter. Using the typical multiecho spin-echo sequence with long echo trains, stimulated echo compensation can enable T2 fitting under conditions of variable radio frequency homogeneity arising from slice profile and in-plane radio frequency variation.(More)
We present a simple and intuitive means for determining the flip angles (FAs) required for smooth transitions between static pseudo steady states (SPSSs) in fast spin echo (FSE) imaging with variable FA (VFA) echo trains. We demonstrate the effectiveness of single and multiple transition pulses to successfully vary refocusing FAs while retaining high signal(More)
PURPOSE To investigate the feasibility of real-time 3D magnetic resonance imaging (MRI) with simultaneous recording of physiological signals for identifying sites of airway obstruction during natural sleep in pediatric patients with sleep-disordered breathing. METHODS Experiments were performed using a three-dimensional Fourier transformation (3DFT)(More)