Abnormal iron deposition associated with the degenerative process could be the source of T2 shortening, which is a useful MR imaging finding in the diagnosis of ALS.

The authors retrospectively evaluated magnetic resonance (MR) images obtained at 1.5 T in 233 patients with portal hypertension and 91 subjects without it and pathologic findings in four resected spleens (one normal). Multiple, tiny (3-8 mm in diameter), low-intensity spots in the spleen were observed in 21 of 233 patients. Among the imaging studies performed in these 21 patients, the spots were seen on five of 14 T1-weighted images, 11 of 20 proton density images, and 12 of 20 T2-weighted images obtained with spin-echo techniques and on 14 of 14 fast-scan images obtained with gradient-echo rephasing. MR images in the 91 subjects did not show such lesions. MR images of the three spleens resected from patients with portal hypertension showed the low-intensity spots, which corresponded to siderotic nodules found at pathologic analysis. Despite limited pathologic confirmation, siderotic nodules (so-called Gamna-Gandy nodules) are considered the most likely cause of multiple low-intensity spots in the spleen.

BACKGROUND AND PURPOSE: MR imaging findings of LYH and pituitary adenomas are similar, but the therapeutic strategies are completely different. The purpose of this study was to evaluate sellar and parasellar MR imaging findings in patients with both diseases, as well as characteristic clinical findings.

A case of Ewing's sarcoma of the bone, arising in the right radius of a 12-year-old girl, which showed unique histologic features after pre-operative treatment, is reported. The light microscopic features of a biopsy sample were those of a small round cell tumor showing positive immunoreaction with antibodies against the product of the MIC 2 gene (O13), neuron-specific enolase, neurofilament, and synaptophysin, but no morphological differentiation. The patient received combined intensive multi-drug chemotherapy and radiation before surgery. Examination of the surgical specimen showed that the tumor was less cellular than that in the biopsy specimen, and was composed mainly of loosely textured large cells mimicking ganglion cells, occasionally forming Homer-Wright rosettes. An immunohistochemical study revealed that neural differentiation was enhanced. Immunoreactivity for Leu-7 also became positive. Although the patient underwent postoperative chemotherapy, she died of multiple lung and bone metastases 30 months after the diagnosis. Autopsy showed that metastatic foci were made up of densely packed small round cells like those seen in the biopsy samples, but associated with prominent Homer-Wright rosettes. To the authors' knowledge, this is the first report of a tumor being replaced almost entirely by ganglion cells after pre-operative chemotherapy and radiotherapy.

Pulverized Japanese bituminous coal (Taiheiyo coal) samples with diameter ranges of 38−75 μm and 180−250 μm were gasified with high-pressure steam in the presence of Ca-based CO2 sorbents. The experiments were carried out at 873 and 973 K and at holding times ranging from 0 to 120 min using a laboratory-scale fixed-bed reactor, and the solid−solid reaction between the Ca-based sorbents and the coal-included minerals during the steam gasification was investigated. Local scanning electron microscopy−energy-dispersive X-ray analysis of the solid residues obtained under different conditions showed that some constituents of the coal-included minerals, such as Si and Al, were contained in the sorbent particles. The solid−solid interaction between the Ca-based sorbents and coal-included minerals became significant at the higher temperature and at longer holding periods. This interaction will locally decrease the CO2 sorption ability of the sorbents. However, when a holding time of less than 10 min was employed, the solid−solid reaction between the minerals and the sorbents was suppressed, even at 973 K, because the rate of formation of inorganic compounds through solid−solid reaction was low. In this case, our target carbon conversion (about 50%) was attainable, owing to the devolatilization during the heating period. Our results indicate that the holding time of the feedstock in the reactor should be shortened to avoid deactivation of the Ca-based sorbents during high-pressure steam gasification.