ABSTRACT
A visual presentation system is described that is inexpensive, easily implemented, and adaptable to most laboratory and clinical settings. Performance evaluations demonstrated a field of view of 26 x 56 degrees, no radiofrequency interference, and high image quality. Although the system was designed for brain activation studies with functional magnetic resonance imaging (MRI), it can also be used for positron emission tomography activation studies and for presenting relaxation videos during clinical MRI.
Subject(s)
Magnetic Resonance Imaging , Photic Stimulation/methods , Costs and Cost Analysis , Humans , Magnetic Resonance Imaging/methods , Photic Stimulation/instrumentation , Tomography, Emission-Computed , Videotape RecordingABSTRACT
Subjective and physiologic effects of 33% inhaled Xe were measured with 15O-water positron emission tomography (PET) in 3 subjects at rest and during visual stimulation. The procedure was well tolerated. Robust functional activations of the visual cortex were obtained after xenon (Xe) inhalation as well as air breathing. However, Xe inhalation was followed by smaller size, but significant decreases of regional cerebral blood flow (rCBF) in visual cortex relative to the air-breathing baseline, both during visual stimulation and at rest. No such decreases were found in other sensory or motor regions.
Subject(s)
Brain/diagnostic imaging , Cerebrovascular Circulation/drug effects , Magnetic Resonance Imaging/methods , Tomography, Emission-Computed , Xenon/pharmacology , Adult , Depression, Chemical , Humans , Male , Oxygen Radioisotopes , Photic Stimulation , Visual Cortex/blood supply , Visual Cortex/drug effects , Visual Cortex/physiology , Water , Xenon/administration & dosageABSTRACT
To obtain a database of accurate anatomical images onto which dosimetry data of electromagnetic fields could be mapped, a healthy Sprague-Dawley rat, rhesus monkey, and pigmy goat were scanned using magnetic resonance imaging (MRI). Axial sections throughout the length of the animals were collected. Sections were 3 mm thick for the rat and 5 mm thick for the monkey and goat. Sagittal sections (2 mm thick) of the rat head were also scanned. Images were recorded on magnetic tape and transferred to computer disk for image enhancement and network distribution. Images are available in 16 bit Big Endian signed or 8 bit TIFF formats. This is the first database of contiguous MRI axial scans of rat, monkey, and goat available for distribution via magnetic tape (4 mm DDS) or Internet file transfer protocol. Digital transfer of the data was selected to preserve the integrity of each image, circumventing the need for the user to scan the images back into a digital format for use with their software. These images should be useful to physiologists, neuroscientists, veterinarians, anatomists, and teachers. Reconstructing these 2-dimensional images into 3-dimensional structures is an effective media for conveying spatial anatomical information in a quick and comprehensive manner.
