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OBJECTIVES The purpose of this study was to determine if the thickness of splint padding could be determined on X-rays, and whether increasing layers of splint padding have an effect on temperature at the skin after placement. METHODS Both in vitro and in vivo testing was performed. Ten cadaveric lower extremities were used. A thermocouple was placed on the posterior calf for temperature determination. Cadavers were used with short leg posterior splints with sidebars placed using various thicknesses of padding: (1) 2 layers of Webril, (2) 4 layers of Webril, (3) 2 × 2 padding (Webril followed by kerlix, then repeated), and (4) bulky cotton padding. A splint with no padding was used as a control. Lateral X-rays of the ankle were obtained. The padding thickness was measured. The change in temperature at the level of the skin was measured throughout the process. The test was then repeated in vivo to correlate the cadaver findings with a live subject. RESULTS The mean thickness of the 5 padding types could be reliably determined on X-ray. Our cadaver temperature data shows that all padding thickness tested decreased temperature change after plaster curing, with no significant difference between wraps. Live subject testing showed similarities between the 2-layer Webril and 2 × 2 padding, and between the 4-layer Webril and bulky padding. CONCLUSIONS Padding thickness can be consistently determined on X-ray. We determined that at least 2 layers of Webril significantly decrease temperature change at the level of the skin caused by plaster curing. Two layers of Webril can be identified on X-ray by measuring at least 1 mm of padding.

Solidification or hot cracks are commonly observed defects in a number of metal alloys and may lead to deterioration of additively manufactured parts quality. In this study, ultra-high-speed x-ray radiography experiments enable the observation and characterization of bundles of hot-cracks that form in monobloc AA6061 substrate. The crack bundles are related to meltpool characteristics and pore formation. Crack propagation rate is also presented for the case of a crack that initiates from a pore. Two types of relevant pore formation are also described, namely keyhole porosity and crack-remelting porosity. The results of this study are expected to facilitate the validation of theoretical and numerical models of solidification cracking.

Polymer electrolyte fuel cells (PEFCs) are expected to be applied in wider range of applications including automobiles, and the operation at higher current density has been required. However, in the operation at high current densities, the performance of PEFCs is degraded due to liquid water accumulation in the gas diffusion layers (GDLs) which prevents the supply of oxygen to the catalyst. Furthermore, heat is generated in catalyst layer due to electrochemical reaction, leading temperature rise inside PEFCs. Since liquid water accumulation is closely related to temperature distribution, it is expected that temperature distribution alters the spots of liquid water accumulation. Therefore, it is necessary to understand the relationships between the liquid water distribution and the temperature distribution in the GDLs to improve the performance at high current density. This study intended to investigate the effects of temperature distribution on liquid water accumulation by in-situ X-ray visualization. Liquid water distribution of 60, 70, and 80 ℃ cell temperature cases were measured by X-ray radiography, and current density was kept 1.5 A/cm2 in all cases. We used a serpentine type cell with ribs and flow channels of 300 µm width with 1.5 x 3.0 mm2 active area. As for GDLs, SIGRACET 29BC was used. The humidity of hydrogen in the anode was fixed at 100%. While, the humidity of air in the cathode was adjusted so that the gap between water vapor pressure and saturation pressure becomes 4.0 kPa. Fig. 1 (a), (b) and (c) shows the liquid water distribution of the 60 ℃, 70 ℃, 80 ℃ cases. It is shown that the liquid water distribution in a region near the MPL/substrate boundary is clearly altered by the cell temperature. This effect is also observed in the averaged profiles of liquid water volume under rib areas (Fig. 1(d)). In Fig. 1(d), liquid water volume in the region near the MPL/substrate boundary (the region between 50 µm to 80 µm) of the 70 and 80 ℃ cases are clearly reduced compared to the 60 ℃ case. Since the overvoltage of each case is almost the same, the resultant temperature gradient inside GDLs due to the heat production is considered to be the same. Meanwhile, the saturated vapor pressure increases more abruptly at higher temperature, since the saturated vapor pressure is more affected by the initial cell temperature. The saturated vapor pressure of the 80 ℃ case is much larger than the other cases, therefore it is suggested that the lower amount of liquid water accumulation of the 80 ℃ case is caused by the larger saturated vapor pressure. Figure 1

A system for visualizing X rays from pulsed discharges in the real-time mode using X-ray intensifying screens is described. Using the system, it is possible to record images of X-ray sources in the energy range of 1–100 keV with a spatial resolution of ∼100 μm. The proposed visualization system has been tested while optimizing the radiative characteristics of the high-current vacuum pulsed discharge. It may be employed when studying of a wide class of x-ray pulsed sources.

Two setups for X-ray visualization of objects interior structure were designed and assembled in TPU. These radiographic systems are based on linear gas-discharge and GaAs semiconductor detectors. During investigation of biological object control of radiation doses has a high priority. In this report radiation dose calculations in X-ray visualization are presented. These calculation also includes dose calculations of sinograms which are used for reconstruction of tomography slices.

Neurons transmit active potentials through axons, which are essential for the brain to function. In this study, the axonal networks of the murine brain were visualized with X-ray tomographic microscopy, also known as X-ray microtomography or micro-CT. Murine brain samples were freeze-dried to reconstitute the intrinsic contrast of tissue constituents and subjected to X-ray visualization. A whole brain hemisphere visualized by absorption contrast illustrated three-dimensional structures including those of the striatum, corpus callosum, and anterior commissure. Axonal tracts observed in the striatum start from the basal surface of the cerebral cortex and end at various positions in the basal ganglia. The distribution of X-ray attenuation coefficients indicated that differences in water and phospholipid content between the myelin sheath and surrounding tissue constituents account for the observed contrast. A rod-shaped cutout of brain tissue was also analyzed with a phase retrieval method, wherein tissue microstructures could be resolved with up to 2.7 {\mu}m resolution. Structures of axonal networks of the striatum were reconstructed by tracing axonal tracts. Such an analysis should be able to delineate the functional relationships of the brain regions involved in the observed network., Comment: 28 pages, 6 figures, 1 table

Alginate-poly-L-lysine-alginate (APA) microcapsules have been explored as vehicles for therapeutic drug and cell delivery. The permselectivity of these capsules provides a unique means of controlled drug release and immunoisolation of encapsulated cells. Immunoisolation is especially attractive as it abrogates the need for chronic immunosuppressive therapy and opens up the possibility for the delivery of numerous cell sources including xenogeneic grafts. APA microcapsules containing cellular therapeutics have proven effective in the short-term treatment of a wide range of diseases requiring enzyme or endocrine replacement therapy, including type I diabetes. If these microcapsules could be noninvasively monitored with X-ray imaging modalities (i.e., fluoroscopy, CT, and digital subtraction angiography), questions such as the ideal transplantation site, the best means of delivery, and the long-term survival of grafts could be better addressed. We have developed two novel alginate-based radiopaque microcapsule formulations containing either barium sulfate (Ba X-Caps) or bismuth sulfate (Bi X-Caps). As compared to conventional, nonradiopaque APA capsules, Ba X-Caps and Bi X-Caps containing human cadaveric islets resulted in a decrease in cellular viability of less than 5% up to 14 days after encapsulation. Both radiopaque capsules were found to be permeable to lectinsor =75 kDa, but were impermeable to lectinsor =120 kDa, thus ensuring the blockage of the penetration of antibodies while allowing free diffusion of insulin and nutrients. The glucose-responsive insulin secretion of the radiopaque encapsulated human islets was found to be unaltered compared to that of unlabeled controls, with human C-peptide levels ranging from 3.21 to 2.87 (Ba X-Caps) and 3.23 to 2.87 (Bi X-Caps) ng/islet at 7 and 14 days postencapsulation, respectively. Using fluoroscopy, both Ba X-Caps and Bi X-Caps could be readily visualized as single radiopaque entities in vitro. Furthermore, following transplantation in vivo in mice and rabbits, single capsules could be identified with no significant change in contrast for at least 2 weeks. This study represents the first attempt at making radiopaque microcapsules for X-ray guided delivery and imaging of cellular therapeutics. While human cadaveric islets were used as a proof-of-principle, these radiopaque capsules may have wide ranging therapeutic applications for a variety of cell types.

Shape memory polymers can be programmed into a secondary geometry and recovered to their primary geometry with the application of a controlled stimulus. Porous shape memory polymer foam scaffolds that respond to body temperature show particular promise for embolic medical applications. A limitation for the minimally invasive delivery of these materials is an inherent lack of X-ray contrast. In this work, a triiodobenzene containing a monomer was incorporated into a shape memory polymer foam material system to chemically impart X-ray visibility and increase material toughness. Composition and process changes enabled further control over material density and thermomechanical properties. The proposed material system demonstrates a wide range of tailorable functional properties for the design of embolic medical devices, including X-ray visibility, expansion rate, and porosity. Enhanced visualization of these materials can improve the acute performance of medical devices used to treat vascular malformations, and the material porosity provides a healing scaffold for durable occlusion.

To determine the extension of a lesion of the fibular ligament with customary techniques is a highly subjective matter, since it underlies personal evaluation criteria. These criteria determine the indication for surgery. Socalled fixation devices are now made available, to avoid a wide margin of errors and to provide a means of attaining standardized and reproducable findings, which facilitate clinical diagnosis. We examined the Scheuba-fixation device in terms of its diagnostic value. In routine application in the clinic the device has proven to be useful, helping to decide on the proper treatment, especially in borderline cases.

Amniography was applied in combination with tomography and the following results were obtained. (1) In 23 normal gravidae, the placenta could be located in 22 of them by the method, its position determined by this method was confirmed at delivery in 21 of the cases. (2) Of 8 cases with antepartum hemorrhage as the principal complaint, one was diagnosed of partial placenta praevia plus presentation of the umbilical cord and another of deep-lying placenta, and the accuracy of the diagnosis was con-firmed at the cesarean section in the former and the delivery per vaginam in the latter. In all the other 6 cases, placenta praevia was found negative by the method, and every time the accuracy of the diagnosis was confirmed at delivery. (3) Of the anomalies of the umbilical cord, presentation, coiling around the neck and relative shortness due to multiple coiling can be diagnosed by application of this method. (4) The diagnosis whether the fetus is alive or dead is also possible by this method. (5) No side-effect of Urografin and no any lesion by the centesis to the mother and the fetus could be observed in any case. (6) 11 pregnant rats were exposed to the same dose of X-ray as at the clinical experiment and the litters were kept and fed for 8 to 16 months after birth. Among the 96 youngs, 25 died during the time of observation, but none of them from leukemia.

A method has been described by means of which cancerous tissue has been made visible in ordinary flat-plate x-rays. Polyvinylpyrrolidone (PVP), a blood plasma expander, has been used as the injection medium because its large molecules are trapped or delayed in their passage through primary or metastatic carcinomatous tissues. For this purpose, PVP with bismuth and PVP with iron have been injected alternately into veins of the arm. Three to six weeks later, opacities which can be seen in flat-plate x-rays identify and reveal the sharply-outlined borders of carcinomatous lesions.

Sialoangiography is demonstrated to be useful in the diagnosis and evaluation of inflammatory processes, and tumors of the major salivary glands and their areas. Parenchymal changes as well as space occupying lesions within the glands, and tumors exerting pressure from outside the gland are shown to manifest their specific changes by their effect upon the ducts, with pathognomonic alterations and distortion of the ducts or normal architecture of the ductal system. Intrinsic duct changes are all due to ductal obstruction and a wide variety of causes is shown. The normal findings, including minor anatomical variations is contrasted with abnormal sialoangiographic findings. These abnormalities are evidenced by changes in the duct morphology and the course of the ducts altered by the presence of intrinsic, extrinsic, or deep lobed tumors. The technique of sialoangiography is discussed. The author's method is outlined, including specific views and special methodology.

In a casual review of the American and English literature, I have found 125 cases of gallstones in children, with or without definite gall-bladder disease. The ages of the children have varied from 46 days to 15 years. This case is being reported because gall-bladder pathology in children is still not a looked-for occurrence, most of the gallstones being found during an exploratory laparotomy or at autopsy. Further, not one of the reports showed X-ray films such as, in this case, made the pre-operative diagnosis of gall-bladder disease, with stone, possible. H. McK., a white male, aged 7, was admitted to Dr. L. A. Montgomery's service with a complaint of almost daily attacks of abdominal pain, for a period of almost two months. The pain had no definite relationship to meals and the attacks varied from five to twenty minutes in duration. The pain was fairly well localized just to the right of the umbilicus, but there was tenderness in this region only during the attacks. The mother stated that “outside” ph...

IN 1948 and 1950 Lindblom1 , 2 reported his experience with diskography. In these reports he described a method of direct visualization of normal and pathologic lumbar intervertebral disks by means of the injection of a readily absorbable contrast medium into the substance of the disk. The procedure appeared to have considerable promise. Our first experience was reported in 1951.3 Subsequent experiences with 89 patients upon whom 169 satisfactory diskograms were obtained were published in 1952.4 The present report includes an additional 165 patients upon whom 339 disks were injected. Sixty-eight of these patients were operated upon, with exploration of 107 disks. . . .

An electronic X-ray system is described which allows more information to be obtained than do the usual radio-graphic methods which lump together the effects of different wavelengths. It gives high contrast images and allows otherwise unnoticeable detail to be detected with a quantitative evaluation of composition. The system has been used to visualize a normal thyroid and analyze it for normal iodine distribution, though a thyroid gland cannot usually be seen at all in a radiograph. An analogy with a new electrocardiographic method is noted.

It is an established fact that the placenta can be visualized in soft-tissue x-ray films in over 90 per cent of all women who are in the third trimester of pregnancy. This was forecast by Speidel and Turner 1 in 1924. In a paper dealing chiefly with x-ray visualization of the uterus and adnexa with the aid of artificial pneumoperitoneum, they stated: "It should be possible, by means of the roentgenogram, by the relation that the head of the fetus bears to the lower segment of the uterus, to determine the degree of encroachment of the placenta upon the internal os, and whether we have a central, lateral, or marginal placenta previa." During the past several years at the Boston Lying-in Hospital we have made x-ray studies of all cases of uterine bleeding and of transverse or oblique position of the fetus occurring during the third trimester of pregnancy. The purpose of this paper is to report our experience regarding the x-ray diagnosis of placenta previa through the use of the soft-tissue technique introduced by Snow and Powell 2 and the cystographic method first described by Ude, Weum, and Urner 3 .

ALTHOUGH the results of surgical treatment of protruded intervertebral disks are better than those when such treatment is not carried out, nevertheless they do leave something to be desired. Therefore, any method of investigation which promises to add to our knowledge of this problem deserves careful consideration. For this reason, when Lindblom's method of roentgenographic visualization of the intervertebral disk came to our attention, we decided to investigate its potentialities. In 1948 Lindblom, 1 of Sweden, published his description of a method of direct injection of the intervertebral disk with a rapidly absorbable water-soluble contrast substance. Although only 15 disks had been so examined, he considered the method of great practical value and superior to myelography in accuracy. In 1950 he published the results of injection of 52 lumbar intervertebral disks. 2 The purpose of this preliminary report is to discuss our experience with the injection of 169 disks. One