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排序方式: 共有916条查询结果,搜索用时 15 毫秒
1.
Two types of contrast media are now used in clinical magnetic resonance imaging (MRI). Intravenous gadolinium-DTPA serves as a marker of blood-brain barrier disruption while intravenous magnetic iron oxide particles are of value in imaging the liver and spleen. The efficacy of MRI is improved with these agents but the examination is prolonged.  相似文献   
2.
A method for measuring flow based on the shifting of the rephasing pulse following slice selection in partial saturation is described. The technique is based on a partial saturation sequence and retains much of the high signal which is a feature of the use of this sequence. Images obtained while encoding for the flow signal compated with those when not encoding appear very similar.  相似文献   
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用混合粘合剂碳糊电极测定丁螺环酮   总被引:6,自引:1,他引:5  
用混合粘合剂碳糊电极测定丁螺环酮张正奇,曾鸽鸣,刘传桂,黎艳飞(湖南大学化学化工系,长沙410082)碳糊电极无毒,制作方便,表面更新容易,应用电位范围广,在药物分析中已有应用[1~5]。我们在液体石腊中加入添加剂,组成混合粘合剂,可显著改善电极的检...  相似文献   
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This communication describes the design and application of a receiver coil operating at liquid nitrogen temperature and intended as a surface coil in a whole-body imager. Its particular application is seen as the external receiver for parasitic internal or implanted detectors.  相似文献   
7.
To assess the effect of stimulus correlated motion on the appearance of functional magnetic resonance images, conventional visual and motor protocols were each performed by four normal volunteers and an image co-registration technique was used to retrospectively monitor subject motion. In three studies synthetic data sets were constructed from single baseline images using the positional information obtained from the co-registration procedure. Cumulative difference images were then created from both the synthetic and functional image sets. Stimulus correlated motion was detected in all eight studies and the synthetic cumulative difference images showed striking similarities to the equivalent functional images in each case.  相似文献   
8.
Y Niv  C Turani  E Kahan  GM Fraser 《Gastroenterology》1997,112(6):2104-2107
Polycystic kidney disease is an autosomal dominant disease that may be associated with cystic disease of the liver. In women, the cysts may develop early and be more troublesome than in men. Cystadenocarcinoma of the pancreas is uncommon, comprising 1% of primary pancreatic malignancies. This case report is the first to describe a familial association between polycystic kidney disease and cystadenocarcinoma of the pancreas and liver in the English medical literature. A patient with autosomal dominant polycystic kidney disease (ADPKD) and multiple hepatic cysts developed cystadenocarcinoma of the pancreas with multiple malignant liver cysts. The patient's mother, sister, and niece had ADPKD, and the patient's sister also died of pancreatic cystadenocarcinoma. We believe that the development of these two disease entities in which the primary pathology is cyst formation has a genetic association. (Gastroenterology 1997 Jun;112(6):2104-7)  相似文献   
9.
Phosphorus was imaged in vivo in human cortical and trabecular bone and the T(1) and T(2) (*) were measured. An ultrashort TE (UTE) pulse sequence (TE = 70 microm) was used with half pulse excitation and radial mapping of k-space from the center out. T(2) (*) was measured using multiple echo times and T(1) was measured both by saturation recovery and by a method using different RF pulse amplitudes. Seven normal subjects (32-85 years) were examined. Phosphorus was imaged, with a true in-plane resolution of 2.9 x 2.9 mm and a signal-to-noise ratio (SNR) of 19:1, in both cortical and trabecular bone. The mean T(2) (*) value was 207 +/- 12 micros, and the mean T(1) value was 8.6 +/- 3.0 sec. Images and measurements were obtained in realistic times on a clinical MR system. This may provide a new approach to characterizing disease of bone.  相似文献   
10.
A new commercial test for the diagnosis of rotavirus gastroenteritis was assessed. With some modifications it compared favourably with electron microscopy and immunofluorescence.  相似文献   
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