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排序方式: 共有1043条查询结果,搜索用时 46 毫秒
981.
Intracranial circulation: preliminary clinical results with three- dimensional (volume) MR angiography 总被引:5,自引:0,他引:5
Masaryk TJ; Modic MT; Ross JS; Ruggieri PM; Laub GA; Lenz GW; Haacke EM; Selman WR; Wiznitzer M; Harik SI 《Radiology》1989,171(3):793-799
The authors assessed the clinical utility of a magnetic resonance angiography technique in the evaluation of intracranial circulation. Eighteen patients with a low likelihood of cerebrovascular disease (control group) and 40 patients with suspected cerebrovascular disease were imaged with a FISP (fast imaging with steady precession) sequence (repetition time of 50 msec, echo time of 15 msec, velocity compensation in the read and section-select directions with acceleration compensation in the read direction, 15 degrees anisotropic volume, and a 1.25-mm partition thickness). Ninety-four percent of images in the control group and 72% of images in the group with cerebrovascular disease were considered useful for diagnosis. This technique can provide accurate images of intracranial circulation and can be performed in conjunction with two-dimensional spin-echo or gradient-echo imaging. It was most useful in the evaluation of patent intracranial aneurysms, vessel displacement, and large-vessel occlusive disease. Disadvantages included limited field of view, persistent signal voids, limited spatial resolution, and inadequate depiction of lesions with slow flow. 相似文献
982.
To devise and implement an in-plane magnetic resonance angiography examination of the carotid bifurcation capable of producing high-resolution images, the authors examined 19 normal carotid arteries and 14 patients with angiographically documented disease with two flow-correction techniques: a three-gradient, velocity-refocused technique with spin-echo (SE) and gradient-echo sequences, and a four-gradient velocity- and acceleration-corrected SE technique. With use of three equal gradients in the read direction, velocity-related phase changes were minimized by placing the dephasing gradient after the 180 degree pulse and near the read gradient. Acceleration effects were minimized through the use of short echo times and cardiac gating. Both velocity- and acceleration-produced phase changes were corrected with the four-gradient scheme but at the expense of some limitations in spatial resolution. Both techniques consistently produced satisfactory images of the carotid bifurcation in healthy individuals. However, the results indicate that the present gradient-phase modulation techniques have several drawbacks, including susceptibility to patient motion, overlapping with the jugular vein, and inability to image carotid stenosis accurately due to turbulence. 相似文献
983.
984.
Fifteen patients with lymphoma and hypercalcemia (greater than or equal to 11.0 mg/dL) were identified by screening the serum chemistry profile obtained from patients upon admission to the Los Angeles County/USC Medical Center. Seven of the 15 (47%) possessed a frankly elevated serum concentration of 1,25-dihydroxyvitamin D [1,25-(OH)2-D]. An additional patient with severe hypercalcemia (16.2 mg/dL) had a serum 1,25-(OH)2-D concentration in the midnormal range, not a suppressed value. To examine the potential existence of hypercalciuria in absence of overt hypercalcemia, prospective screening of 23 normocalcemic patients with lymphoma was undertaken. Four of the 23 patients (17%) had increased fractional urinary calcium excretion rates (0.35 +/- 0.3 mg calcium/100 mL glomerular filtrate [GF], mean +/- SE; normal, less than 0.16 mg/100 mL GF); two of the hypercalciuric patients had a frankly elevated serum 1,25-(OH)2-D concentration. Of the 19 hypercalcemic/hypercalciuric lymphoma patients identified, none had an elevated serum immunoreactive parathyroid hormone concentration. Fourteen of the 19 hypercalcemic/hypercalciuric patients (74%) suffered from B-cell neoplasms, three had Hodgkin's lymphoma, and two had adult T-cell leukemia/lymphoma. All hypercalcemic/hypercalciuric patients had widespread disease (stage III or IV). Six patients, four with hypercalcemia and two with hypercalciuria, had acquired immunodeficiency syndrome (AIDS). These data suggest that the deregulated synthesis of a 1,25-(OH)2-D-like metabolite is a common cause of hypercalcemia and hypercalciuria in patients with lymphoma including patients with AIDS-associated tumors. 相似文献
985.
One-stage treatment of congenital dislocation of the hip in older children, including femoral shortening 总被引:6,自引:0,他引:6
R D Galpin J W Roach D R Wenger J A Herring J G Birch 《The Journal of bone and joint surgery. American volume》1989,71(5):734-741
We reviewed the results of primary operative treatment in twenty-five patients (thirty-three hips) who were two years or older and had congenital dislocation of the hip. None of the patients had had previous treatment for the dislocation. Preliminary traction was not used in any patient. Femoral shortening and, in twenty-one hips, pelvic osteotomy were performed at the time of open reduction. At the most recent follow-up (average, three years and seven months), according to the radiographic classification system of Severin, there were seven excellent, seventeen good, and eight fair results; one hip had a poor result. Avascular necrosis developed in three of the thirty-three hips. At follow-up, these hips had a radiographic result of excellent, good, and fair, respectively. Twenty-one patients (twenty-eight hips) were reviewed with respect to range of motion and recovery from limb-length discrepancy. According to the rating system of Ferguson and Howorth, there were seventeen excellent, seven good, and three fair results; one hip had a poor result. It was concluded that children who are two years or older and who have a congenital dislocation of the hip can safely be treated with an extensive one-stage operation consisting of open reduction combined with femoral shortening and, often, pelvic osteotomy, without increasing the risk of avascular necrosis. The limb-length discrepancy that is produced by the shortening does not appear to cause a clinical problem. 相似文献
986.
987.
988.
G. R. B. Skinner M. E. Turyk C. A. Benson G. D. Wilbanks P. Heseltine J. Galpin R. Kaufmann L. Goldberg C. E. Hartley A. Buchan 《Medical microbiology and immunology》1997,186(1):31-36
A randomised, placebo-controlled, multi-centre trial of intracellular subunit herpes simplex virus (HSV) type 1 vaccine NFU.Ac.HSV-1(S–)MRC (Skinner vaccine) was conducted at three medical centres in the United States. Subjects with documented herpes genitalis
of at least 1-year duration and a history of six or more genital HSV recurrences in the 12 months prior to study entry were
randomised to receive vaccine or placebo at 0, 1 and 2 months. Vaccination induced significant neutralising, enzyme-linked
immunosorbent assay and lymphocyte transformation response to HSV-1 antigen. The frequency of recurrences was reduced in the
vaccinated female patients at both 3 and 6 months following vaccination with an overall reduction in patients of both sexes
which did not reach statistical significance. Recurrence severity was reduced as measured by decreased number of lesions and
associated symptoms per recurrence (P = 0.04). The data suggest that clinical manifestations of latent HSV genital infection may be modified by therapeutic immunisation.
Received: 19 February 1997 相似文献
989.
990.