Slice thickness

Figure Bl.14.5. J2-weighted images of the propagation of chemical waves in an Mn catalysed Belousov-Zhabotinsky reaction. The images were acquired in 40 s intervals (a) to (1) using a standard spin echo pulse sequence. The slice thickness is 2 nun. The diameter of the imaged pill box is 39 nun. The bright bands...

B1.18.5.2 OPTICAL SECTIONING, SMALLEST SLICE THICKNESS AND AXIAL RESOLUTION... 

The slice thickness is proportional to the wavelengdi of the light and a fiinction of the aperture angle. For X = 0.5 pm, the slice thickness is about 0.25 pm for a = nil. Obviously, the point spread fiinction serves also to... 

MHz (left). The trabecular structure and 512 x 256 pixels, FOV 6x3 mm, resolution the muscle tissue are clearly resolved, the 11.7 pm per pixel, slice thickness 64 pm, TR... 

Figure 2.2.14 shows cross-sections of salmon acquired with a gradient echo sequence (TR = 30 ms, TE = 15 ms, slice thickness = 4 cm, image matrix = 128 x 128, total acquisition time = 3.84 s). For the female salmon, roe were clearly visualized as dark regions because the T2 is shorter than that of the surrounding tissues. For the male salmon, milt was observed instead of roe. However, the image intensity of the milt was similar to that of the surrounding tissues. 

Fig. 5.2.7 Identification of location and size of local pulses within the trickle bed. A high spatial resolution image (in-plane spatial resolution 1 75 [tm x 175 im slice thickness 1 mm) is overlayed with a standard deviation map calculated from images acquired at a spatial resolution of in-plane spatial resolution 1.4 mm x 2.8 mm slice thickness 2 mm.

Fig. 5.5.14 Schematic diagram showing how the double-phase encoded DEPT sequence achieves both spatial and spectral resolution within the reactor, (a) A spin-echo ]H 2D image taken through the column overlayed with a grid showing the spatial location within the column of the two orthogonal phase encoded planes (z and x) used in the modified DEPT sequence. The resulting data set is a zx image with a projection along y. In-plane spatial resol-ution is 156 [Am (z) x 141 [xm (x) for a 3-mm slice thickness. The center of each volume from which the data have been acquired is identified by the intersection of the white lines. The arrow indicates the direction of flow.

Fig. 12 Visualization of mean conversion, X, within selected volumes located within the slice section identified in Fig. 11. The local volumes have in-plane dimensions of 1.5 mm x 1.5 mm and a depth (image slice thickness) of 500 pm. Data are shown for three feed flow rates (a) 0.025, (b) 0.05, and (c) 0.1 ml min-1. As flow rate increases, the residence time characterizing the bed decreases and, as expected, conversion also decreases. Reprinted from ref. 33, with kind permission of Springer Science and Business Media.

Fig. 5. Standard fast spin-echo imaging of the pelvis and the lower leg. Typical contrasts between musculature and other tissues are demonstrated. Bl = bladder, Fe = femur. Gluteus = gluteus muscle. Original recording parameters matrix 192 x 256, slice thickness 6 mm, a-c field of view (fov) = 380 mm, d-f fov = 180 mm. (a) and (d) Proton density weighting TR = 5000 ms, TE = 12 ms. (b) and (e) Ti-weighting TR = 500 ms, TE = 12 ms. (c) and (f) 7 2-weighting TR = 5000 ms, TE = 100 ms.

Liver slices were initially prepared manually using razor blades or mechanical instruments such as the Stadie Riggs tissue sheer [4]. The reproducibility of the thickness of the slices at that time was largely dependent on the skills of the operator. Of note is the fact that the minimal slice thickness that could be produced was about 0.5 mm. This dimension appeared to limit the penetration of nutrients and oxygen into the inner cell layers central necrosis in the slice occurred during incubation [35]. 

Gamble, M. H. and Rice, P. (1988). The effect of slice thickness on potato crisp yield and composition. ]. Food Eng. 8, 31-46. 

X 10 grm. ions per sq. cm. The solution contains 10 grm. ions per c.c., hence the slice thickness which must be denuded is 1 6 X 10 cms., since the tailing off is gradual in character this thickness is a minimum estimate of the thickness of the diffuse layer. 

Steingard et al., 1996 65 DD 18 PC 6-17 Structural MRI, 5 mm slice thickness DD < PC frontal lobe volume DD > PC lateral ventricular volume... 

Botteron et al., 14 MZ and 22 DZ twins discordant for MDD 12 MZ and 2 DZ NC twins 17-23 Structural MRI, 1 mm slice thickness Twins with history of MDD < twins no history of MDD = NC subgenual prefrontal cortex volume... 

De Beilis et al., 1999 44 PTSD 20/44 with comorhid MDD 61 NC 6-17 Structural MRI, 1.5 mm slice thickness PTSD = PTSD + MDD = NC hippocampal volume PTSD = PTSD + MDD > NC lateral ventricle volume PTSD = PTSD + MDD < NC middle and posterior regions of the corpus callosum... 

There is also an Urschel model CC sheer, able to produce flat potato slices, standard Crinkle, V slices, oval shreds, crescent shred, V shred, and strip cuts. Then there is the Urschel model GRL strip cutter, designed specifically for cutting plain and crinkle cut potato strips with slice thicknesses up to 14 mm and crosscut knife cuts from 7.1 to 22.2 mm. 

D image is extracted from individual points along the spectral range (2.4-5 ppm). Three series of images are shown within each series the chemical shift separation between images is 0.065 ppm. This complete data set took approximately 27 h to acquire—as a 128 x 128 data array with in-plane resolution of 140 pm x 140 pm for an image slice thickness of 1mm. 

Fig. 19. 2-D MR image of an oscillating chemical reaction occurring within a bed of diameter 15 mm packed with 1-mm-diameter glass beads. In-plane resolution was 195 pm x 195 pm, and the image slice thickness was 1 mm. A single image was acquired in 1 s. Chemical waves are imaged as a result of the...

Clearly by working with typical spatial resolutions of approximately 30-50 pm, individual pores within the material are not resolved. However, a wealth of information can be obtained even at this lower resolution (53,54,55). Typical data are shown in Fig. 20, which includes images or maps of spin density, nuclear spin-lattice relaxation time (Ti), and self-diffusivity of water within a porous catalyst support pellet. In-plane spatial resolution is 45 pm x 45 pm, and the image slice thickness is 0.3 mm. The spin-density map is a quantitative measure of the amount of water present within the porous pellet (i.e., it is a spatially resolved map of void volume). Estimates of overall pellet void volume obtained from the MR data agree to within 5% with those obtained by gravimetric analysis. 

Fig. 20. Spin density, and water diffusion images for a 2.2-inm-diameter, spherical silica catalyst support pellet. In-plane pixel resolution was 45 pm x 45 pm image slice thickness was 0.3 mm. (a) Spin-density map lighter shades indicate higher liquid content, (b) map (150 00 ms) lighter shades indicate longer values of Ti. (c) Diffusivity map ((0-1.5) x 10 m s ) lighter shades indicate higher values of water diffusivity within the pellet.

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