[1] Recent advances in underwater vehicle navigation and sonar technology now permit detailed mapping of complex seafloor bathymetry found at mid-ocean ridge crests. Imagenex 881 (675 kHz) scanning sonar data collected during low-altitude ( 5 m) surveys conducted with DSV Alvin were used to produce submeter resolution bathymetric maps of five hydrothermal vent areas at the East Pacific Rise (EP...

OBJECTIVE To investigate the origin of signals from scanning laser Doppler flowmetry (SLDF) and the influence of axial scan depth on the measurement of blood flow in the rat retina. METHODS We performed SLDF in 5 adult Sprague-Dawley rats using a specially modified Heidelberg retina flowmeter. Axial scans were obtained from +2 diopters (D) to -3 D (in steps of 0.25 D) or from +1 D to -2 D (in...

PURPOSE To visualize, quantitatively assess, and interpret outer retinal morphology by using high-speed, ultrahigh-resolution (UHR) OCT. METHODS Retinal imaging was performed in the ophthalmic clinic in a cross-section of 43 normal subjects with a 3.5-microm, axial-resolution, high-speed, UHR OCT prototype instrument, using a radial scan pattern (24 images, 1500 axial scans). Outer retinal la...

PURPOSE To report choroidal thickness and volume in healthy eyes using swept source optical coherence tomography (SS-OCT). METHODS A prospective observational study of 122 patients examined with swept source OCT (DRI-OCT, Topcon, Japan). In each eye, we performed 256 horizontal scans, 12 mm in length and centered on the fovea. We calculated choroidal thickness manually with a built-in caliper...

PURPOSE We aimed to investigate white matter diffusivity abnormalities in hereditary spastic paraplegia with thin corpus callosum (HSP-TCC) patients in relation with electrophysiological findings. MATERIALS AND METHODS Brain magnetic resonance imaging (MRI) and diffusion tensor imaging were performed on four HSP-TCC patients and 15 age-matched healthy subjects. Voxel-wise statistical analysis...

PURPOSE Magnetic resonance imaging (MRI) was used to map the refractive index distribution in human eye lenses in vivo and to investigate changes with age and accommodation. METHODS Whole-eye MR images were obtained for sagittal and transverse axial planes in one eye each of 15 young (19-29 years) and 15 older (60-70 years) subjects when viewing a far ( approximately 6 m) target and at indivi...

The chiral self-discrimination of twelve molecules showing axial chirality has been studied. They included peroxides, hydrazines, carboxylic acids, amides, and allenes. The homo and heterochiral dimers of the selected compounds, that present two hydrogen bonds, have been studied by means of density functional theory ~B3LYP/6-311G**! and ab initio ~MP2/6-311G** and MP2/6-31111G**! methods. The e...

Elastography imaging is performed by subjecting the tissue under investigation to a form of mechanical excitation. The resultant tissue displacement vector is measured and can be used compute the spatial variation of strain within the tissue. These strain maps, known as elastograms, serve as surrogates for tissue elasticity. While elastography can be performed with any imaging modality, ultraso...

Fig. 2 Results for three HS pulses: a high bandwidth pulse (row 1), a reduced bandwidth pulse (row 2), and an optimized pulse with reduced bandwidth (row 3). Flip-angle maps are calculated on the grid of targeted static and RF field variations (column 1) and within an axial slice of the human brain (column 2). Frequency profiles for B1/ B1,nom intensities of 0.35, 0.50, 0.75, and 1.00 are shown...

images of VPM-PET (left), Ktrans from ETM (middle), and EFPM (right). Choroid Plexus (thick arrow) and pituitary gland (arrow heads) are clearly depicted. The GCV shows high Ktrans on the maps of ETM, rendered with red color, but not EFPM. Note that GCV and other large vessels were not found on the PET image render blue representing lowest intensity. Figure 2. Axial (1st row) and sagittal (2nd ...