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Chemical-shift selective imaging with an improved selective presaturation pulse can be used to suppress the fat signal uniformly across the entire abdominal cavity. The required magnetic field homogeneity is no higher than for a routine diagnostic scan. Therefore, no extra setup time for shimming is needed. The technique has been implemented on our clinical system for routine fat suppression scans. © 1991 Academic Press, Inc. © 1991 Academic Press, Inc.

We report the case of a young black male with a spinal intradural granulocytic sarcoma proved by needle aspiration. The tumor was evaluated by myelography, computed tomography, and magnetic resonance imaging (MRI). Other than its rarity, the “dripping candle wax” appearance on MR T1-weighted images and the lack of enhancement with Gd-DTPA makes this case unique. Progressive changes of the tumor following chemo- and radiotherapy were successfully demonstrated by MR.

The combination of a paramagnetic agent with an oil emulsion can uniformly enhance the small bowel. We discovered that the entire small bowel becomes homogeneously brighter than its surroundings when imaged with all commonly utilized pulse sequences. We have tried various combinations of ferric ammonium citrate, ferrous sulfate, gadolinium-DPTA and corn oil, olive oil and peanut oil. All paramagnetic oil emulsions tested were uniformly distributed throughout the small bowel, but the enhancement effect is much stronger with the ferric ammonium citrate and gadolinium-DPTA oil emulsions. We have also developed a mixture of Geritol, corn oil, ice cream and milk, which uniformly coats the small bowel wall, has good enhancement effect, tastes good, and is nutritious. With this dietary contrast, retroperitoneal structures including the pancreas can be well delineated. We conclude that the combination of a paramagnetic agent with an oil emulsion can work as a safe and effective magnetic resonance imaging (MRI) oral contrast agent with high patient acceptance.

We compared the effectiveness of 1 mM Geritol, 12% corn oil emulsion, Kaolin-pectin, single contrast oral barium sulfate, and effervescent granules as enteric magnetic resonance imaging (MRI) contrast agents. Five volunteers were recruited. Each volunteer ingested for examinations, separated by at least one week, either 500 ml of each of the liquid preparations or two packets of the CO2 granules (producing 400 ml of CO2 per packet). Abdominal MR images were then obtained using a 1.5 T Magnetom imager and SE 550/22, SE 2000/45/90 and FISP 40/18/40 degrees pulse sequences. The oil emulsions were best tolerated. Barium sulfate caused the greatest amount of nausea, followed by Geritol and Kaolin-pectin. With FISP 40/18/40 degrees, 60%-80% of the small bowel was well delineated using oil emulsion, Kaolin-pectin, or barium sulfate. We conclude that oil emulsion was by far the best enteric MR contrast agent in our study. Good delineation of the small bowel and pancreas can be achieved using oil emulsion and gradient echo pulse sequences. The lack of side-effects and the excellent taste make it highly acceptable to human subjects.

A chemical procedure is reported to modify the semiconductor surface which results in an efficient p-InP/S/sup 2-/,Sx/sup 2-/ photoelectrochemical cell. The procedure is as follows: The p-InP electrode was initially etched in 12M HCl for 1-2 minutes, followed by immersion in polysulfide solution (1M Na/sub 2/S+1M/sub 2/S or 2.5M Na/sub 2/s+1M S+1M NaOH. To the polysulfide-wetted surface of the p-InP, a drop of 0.2M CoCl/sub 2/ was added. A black precipitate of cobalt sulfide was immediately formed, the majority of which was rinsed off with deionized water. 7 refs.

The photoelectrochemical properties of cells based on the solid polymer electrolyte (SPE) poly(ethylene oxide)/NaSCN with Na2S/S as a redox species are investigated experimentally. The preparation of the SPE is described in detail. Current/voltage curves or voltage/time are shown for cells using p-InP/SPE/conducting-glass, n-GaAs/SPE/conducting-glass, and p-InP/SPE/n-CdS structures. It is concluded that practical cells based on SPE of this type will require increases in the ionic conductivity of poly(ethylene oxide). 13 references.

Photoelectrochemical cells having the capability of energy storage are covered. Photoanodes used for these cells were selected from MoSe2, GaAs and CdSe. Redox electrolyte species present at the semiconductor–electrolyte interface included Br–/Br2(MoSe2), S2–/S2–n(CdSe) and Se2–/Se2–2(GaAs). Electroactive materials at the counter-electrode of the storage systems were I–I2, Se2–/Se2–2 and Cd.The performance of these photoelectrochemical storage cells for charge upon photoanode illumination and their subsequent electrochemical discharge is discussed.