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We carried out an investigation to identify neuromelanin-containing noradrenergic and dopaminergic neurons in the locus ceruleus and substantia nigra pars compacta of healthy volunteers and patients with Parkinson's disease using a newly developed magnetic resonance imaging technique that can demonstrate neuromelanin-related contrast. The high-resolution(More)
BACKGROUND AND PURPOSE A reduction in the area of the substantia nigra (SN) has been shown in patients with Parkinson disease. The substantia nigra is anteroinferolateral to the red nucleus, and it is important to precisely locate its true anatomic location to accurately measure SN area. Our purpose was to determine the exact location of the substantia(More)
PURPOSE To investigate age-related changes in the locus ceruleus (LC) in healthy subjects using neuromelanin magnetic resonance (MR) imaging at 3 Tesla. METHODS We examined 64 healthy volunteers (aged 23 to 80 years) using neuromelanin-sensitive T1-weighted images and measured the contrast of areas of high signal intensity corresponding to the LC. (More)
PURPOSE To investigate the difference in enhancement effects and relaxivities of the gadolinium chelate at 1.5 and 3 Tesla (T) and to elucidate the contribution of the high magnetic field to contrast enhancement in spin-echo (SE) and gradient-echo (GRE) images. METHODS Phantoms containing water with or without gadopentetate dimeglumine (Gd-DTPA) at(More)
PURPOSE To evaluate the performance and efficacy for intensity inhomogeneity correction of various sequences of the human brain in 7T MRI using the extended version of the unified segmentation algorithm. MATERIALS Ten healthy volunteers were scanned with four different sequences (2D spin echo [SE], 3D fast SE, 2D fast spoiled gradient echo, and 3D(More)
BACKGROUND/AIMS Despite improvements in endoscopic hemostasis and pharmacological therapies, upper gastrointestinal (UGI) ulcers repeatedly bleed in 10% to 20% of patients, and those without early endoscopic reintervention or definitive surgery might be at a high risk for mortality. This study aimed to identify the risk factors for intractability to initial(More)
PURPOSE To determine whether and to what degree absolute apparent diffusion coefficient (ADC) values vary between different imagers, vendors, field strengths, and intraimager conditions. MATERIALS AND METHODS Informed consent and institutional review board approval were obtained. Diffusion-weighted (DW) images with nearly identical parameters were(More)
OBJECT Cerebral hyperperfusion after carotid endarterectomy (CEA) impairs cognitive function and is often detected on cerebral blood flow (CBF) imaging. The purpose of the present study is to investigate structural brain damage seen on magnetic resonance (MR) images obtained in patients with cerebral hyperperfusion and cognitive impairment after CEA. (More)
BACKGROUND We investigated alterations in the substantia nigra pars compacta (SNc) and locus ceruleus (LC) in schizophrenic and depressive patients by using a neuromelanin-sensitive magnetic resonance imaging (MRI) technique that enables direct visualization of these nuclei and examined whether this technique could distinguish between these disorders and(More)