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Duyn JH van Gelderen P Talagala L Koretsky A de Zwart JA 《Journal of magnetic resonance imaging : JMRI》2005,22(6):751-753
Measurement of brain perfusion using arterial spin labeling (ASL) or dynamic susceptibility contrast (DSC) based MRI has many potential important clinical applications. However, the clinical application of perfusion MRI has been limited by a number of factors, including a relatively poor spatial resolution, limited volume coverage, and low signal-to-noise ratio (SNR). It is difficult to improve any of these aspects because both ASL and DSC methods require rapid image acquisition. In this report, recent methodological developments are discussed that alleviate some of these limitations and make perfusion MRI more suitable for clinical application. In particular, the availability of high magnetic field strength systems, increased gradient performance, the use of RF coil arrays and parallel imaging, and increasing pulse sequence efficiency allow for increased image acquisition speed and improved SNR. The use of parallel imaging facilitates the trade-off of SNR for increases in spatial resolution. As a demonstration, we obtained DSC and ASL perfusion images at 3.0 T and 7.0 T with multichannel RF coils and parallel imaging, which allowed us to obtain high-quality images with in-plane voxel sizes of 1.5 x 1.5 mm(2). 相似文献
74.
An in vitro is described that attempts to detect patients with a potential for adverse systemic reactions to contrast material. This test involves measuring the rate of conversion of prekallikrein to kallikrein under certain standard conditions. In a preliminary retrospective study, the test could be used to identify such patients with a sensitivity of 88%, a specificity of 82%, and a predictive value of 79%. 相似文献
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Duyn A Van Eijkeren M Kenter G Zwinderman K Ansink A 《Acta obstetricia et gynecologica Scandinavica》2002,81(4):351-355
BACKGROUND: Only a small proportion of cervical cancer recurrences is detected during routine follow-up. We investigated which percentage of recurrences is detected during follow-up, which diagnostic tools are helpful to detect recurrent disease and which factors are of prognostic significance once recurrent disease has been established in patients treated for cervical cancer stage IB-IVA. METHODS: Characteristics of the primary tumor, characteristics of recurrent disease and follow-up were collected retrospectively from clinical records of 277 patients who achieved a complete remission of at least 3 months after primary treatment for cervical cancer in 1992, 1993 and 1994 in three university hospitals in the Netherlands. RESULTS: Of 277 patients, 47 (17%) developed recurrent disease; this was most often detected after self-referral (45%), and in 32% during routine follow-up. Survival did not differ significantly between these two groups. The presence of symptoms (87%) was the most important first abnormal test result leading to diagnosis of recurrence. In univariate analysis, disease-free interval (DFI) and treatment modality were significant prognostic factors for crude survival of recurrence. However, treatment modality varied considerably and the subgroups were small. Therefore, multivariate analysis was not feasible and clinically valid conclusions could not be drawn. CONCLUSIONS: In only 32% of all cases, recurrence was detected during a scheduled follow-up visit. In the majority of patients, recurrent cervical cancer was detected by symptoms (87%). In recurrent disease, DFI was a prognostic factor for survival. 相似文献
77.
Duyn A Van Eijkeren M Kenter G Zwinderman K Ansink A 《Acta obstetricia et gynecologica Scandinavica》2002,81(8):759-763
BACKGROUND: Only a small proportion of cervical cancer recurrences is detected during routine follow-up. We investigated which percentage of recurrences is detected during follow-up, which diagnostic tools are helpful to detect recurrent disease and which factors are of prognostic significance once recurrent disease has been established in patients treated for cervical cancer stage IB-IVA. METHODS: Characteristics of the primary tumor, characteristics of recurrent disease and follow-up were collected retrospectively from clinical records of 277 patients who achieved a complete remission of at least 3 months after primary treatment for cervical cancer in 1992, 1993 and 1994 in three university hospitals in the Netherlands. RESULTS: Of 277 patients, 47 (17%) developed recurrent disease; this was most often detected after self-referral (45%), and in 32% during routine follow-up. Survival did not differ significantly between these two groups. The presence of symptoms (87%) was the most important first abnormal test result leading to diagnosis of recurrence. In univariate analysis, disease-free interval (DFI) and treatment modality were significant prognostic factors for crude survival of recurrence. However, treatment modality varied considerably and the subgroups were small. Therefore, multivariate analysis was not feasible and clinically valid conclusions could not be drawn. CONCLUSIONS: In only 32% of all cases, recurrence was detected during a scheduled follow-up visit. In the majority of patients, recurrent cervical cancer was detected by symptoms (87%). In recurrent disease, DFI was a prognostic factor for survival. 相似文献
78.
Excel97在药物分析中的应用 总被引:1,自引:0,他引:1
目的:在药物分析中,电子表格软件MicrosoftExce197for Windows。方法:利用Excel的数据处理功能,进行药物的图表绘制、数据计算和统计处理,回归分析,特别是计算分析,并可建立分析数据库。结果和结论:Excel操作简单,功能强大,数据分析工作直观。 相似文献
79.
目的:比较国产辛伐他汀与进口辛伐他汀治疗原发性高胆固醇血症的疗效及安全性。方法:采用开放区组随机对照、多中心的临床设计。150例高胆 固醇血症病人分为验证组(50例)、对照组(48例)和开放组(52例),剂量均为每晚顿服10mg,服药8周。结果:验证组与对照组服药前后比较,血清总胆 固醇(TC)分别降低26.36%和28.3%,低密度脂蛋白胆固醇(LDL-C)分别降低33.17%和35.51%;验 相似文献
80.
Diet and cancer prevention: the fiber first diet 总被引:3,自引:0,他引:3
Diet can play a major role in cancer prevention. The international
differences in cancer incidence are largely accounted for by lifestyle
practices that include nutrition, exercise, and alcohol and tobacco use.
About 50% of cancer incidence and 35% of cancer mortality in the U.S.,
represented by cancers of the breast, prostate, pancreas, ovary,
endometrium, and colon, are associated with Western dietary habits. Cancer
of the stomach, currently a major disease in the Far East, relates to
distinct, specific nutritional elements such as excessive salt intake. For
these cancers, information is available on possible initiating genotoxic
factors, promoting elements, and prophylactic agents. In general, the
typical diet in the United States contains low levels of the potent
carcinogenic agents, heterocyclic amines, formed during the cooking of
meats. It provides only about half the potent appropriate fiber intake and
is high in calories. About twice as many calories as would be desirable
come from fat, certain kinds of which enhance the development of cancers.
Other foods with functional properties, such as soy products and tea, can
be beneficial. To achieve reduction in risk of certain cancers, diet must
be optimized, primarily to reduce caloric intake and the fat component. The
latter should be 20% or less of total caloric intake and fiber should be
increased to 25- 35 g per day for adults. One approach to achieving these
goals is the Fiber First Diet, a diet designed around adequate fiber intake
from grains, especially cereals, vegetables, legumes, and fruits, which
thereby reduces both calorie and fat intake. Such dietary improvements will
not only reduce cancer and other chronic disease risks, but will contribute
to a healthy life to an advanced age. A corollary benefit is a lower cost
of medical care.
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