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711.
712.
Hirschprung disease is usually diagnosed in infancy. Occasionally patients reach adulthood without diagnosis or treatment. Four cases of adult Hirschprung disease are described. The principal radiographic findings are a markedly dilated, feces-filled colon above the zone of transition; a narrowed rectum; a cone- or funnel-shaped zone of transition; and a mosaic colonic pattern caused by collapsed redundant mucosa after colonic cleansing. In an adult, identification on a barium enema examination of an abrupt, smooth transition zone in the rectum with proximal colonic dilatation, in conjunction with an appropriate clinical history, should suggest the diagnosis of adult Hirschprung disease. 相似文献
713.
714.
Suspected recurrent rectosigmoid carcinoma after abdominoperineal resection: MR imaging and histopathologic findings 总被引:17,自引:1,他引:16
Eleven patients who underwent abdominoperineal resection for rectosigmoid carcinoma were examined with magnetic resonance (MR) imaging for suspected recurrent tumor in the presacral space. There were 12 suspected masses in the 11 patients. Ten lesions were malignant, and in two lesions only nonneoplastic inflammatory tissue was found. The signal intensity (SI) of each lesion relative to that of muscle was determined visually and correlated with the histologic findings at surgery or biopsy. The SIs of malignant and benign lesions were indistinguishable. All lesions showed areas of high SI that correlated with carcinoma and tumor necrosis or with non-neoplastic inflammation and edema. Areas of low SI corresponded to reactive fibrous tissue (desmoplastic reaction) with small islands of tumor or to nonneoplastic fibrosis. MR imaging can be useful in determining the extent of suspected tumors, but SIs on T2-weighted images do not permit histologic diagnosis. In particular, distinction of benign from malignant tissue is difficult in tumors with a desmoplastic reaction. 相似文献
715.
Benign esophagorespiratory fistulas in adults 总被引:2,自引:0,他引:2
Four benign esophagorespiratory fistulas, three secondary to granulomatous disease and one presumed to be congenital, have been diagnosed in adults at the authors' institution in the past year. The patients had symptoms of chronic or recurrent pulmonary infections, and two experienced coughing after swallowing. Chest radiographs demonstrated refractory consolidation, with or without cavitation and frequently accompanied by an air-distended esophagus. Barium studies were diagnostic. All patients responded well to antibiotic and surgical therapy. 相似文献
716.
717.
718.
Pulmonary abnormalities and PET data analysis: a retrospective study 总被引:13,自引:0,他引:13
Lowe VJ; Duhaylongsod FG; Patz EF; Delong DM; Hoffman JM; Wolfe WG; Coleman RE 《Radiology》1997,202(2):435
719.
Gamma camera radionuclide images: improved contrast with energy- weighted acquisition 总被引:4,自引:0,他引:4
An energy-weighted acquisition (EWA) technique has been developed that utilizes all scintillation events, weighting their contributions depending on their energy, to formulate a radionuclide image. Photopeak events from primary radiation contribute positively; scatter events contribute negatively, providing for scatter subtraction and improved image contrast. EWA is employed with an on-line weighted-acquisition module (WAM) as the data are acquired, rather than as a postprocessing technique. EWA was compared with normal window imaging in patients and in phantoms. For gallium-67 and thallium-201, contrast improved by as much as 40%. A much smaller improvement in contrast was observed with technetium-99m due to its ideal monoenergetic emissions. Single photon emission computed tomographic studies also showed improved contrast and were without artifact. EWA has great promise, and with further development quantitative scatter correction may be possible. 相似文献
720.
In the present study we investigate the nature of the murine bone marrow cell subset responsible for the marked increase in histamine synthesis induced by interleukin-3 (IL-3). Because mast cells, and eventually their committed precursors, represent a potential source of histamine in this context, we examined their possible participation in this biologic activity with particular attention. We provide evidence that neither of these populations respond to IL-3 in terms of histamine synthesis and that other differentiated end cells or stromal components of the bone marrow are also not involved in this phenomenon. Starting from these findings, we further characterized the immature hematopoietic compartment responsible for IL-3-induced histamine synthesis using fluorescence-activated cell sorter (FACS) sorting based on rhodamine retention or wheat germ agglutinin (WGA) affinity. These procedures have allowed us to ascribe the following features to histamine-producing cells: (1) They belong to a low-density, progenitor- enriched bone marrow subset containing cells of relatively important size and internal structure. (2) The highest histamine levels are generated by the rhodamine-bright fraction of this population, while the most primitive rhodamine-dull cells do not express this biologic activity. (3) Histamine-producing cells do not copurify with colony- forming units in spleen day 7 and day 12 in WGA-bright fractions. (4) Their enrichment is associated with increased frequencies of cells forming colonies in methylcellulose (CFU-C), suggesting the involvement of several progenitors with partially limited differentiation potential in this biologic activity. 相似文献