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71.
Y Zhang S Seshadri R C Ellison T Heeren D T Felson 《American journal of epidemiology》2001,154(9):795-802
Previous studies have examined the relation of endogenous estrogen levels or estrogen replacement therapy to the risk of poor cognitive function, but results have been inconclusive. Bone mineral density has been proposed as a marker for cumulative estrogen exposure. The authors studied the relation of bone mineral density to the prevalence of verbal memory impairment among 4,304 elderly subjects in the Third National Health and Nutrition Examination Survey (1988-1994). Bone mineral density was measured in five regions of the proximal femur with dual-energy x-ray absorptiometry. Verbal memory was assessed using delayed recall of a three-item word list and a six-item story. Verbal memory impairment was defined as a combined score of <4. The prevalence of verbal memory impairment for each increasing bone mineral density quintile at the femoral neck was 8.35, 5.74, 5.22, 5.00, and 3.38% in women and 11.54, 7.27, 8.47, 6.29, and 5.89% in men, respectively. With adjustment for age, sex, and other covariates, the prevalence ratios of verbal memory impairment for each increased bone mineral density quintile were 1.00, 0.64, 0.65, 0.55, and 0.44, respectively (p for trend < 0.001). These results suggest that bone mineral density in the elderly is associated with verbal memory impairment. The mechanisms underlying this relation are not understood, but cumulative exposure to estrogen may play a role. 相似文献
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Two hundred and ninety one women were evaluated for cervical cancer by cytology and colposcopy. Of these, 152 patients underwent colposcopically directed biopsy for histological evaluation. Colposcopy and cytology were in agreement in 88 per cent of cases whereas colposcopy and histopathology were in agreement in 79 per cent of cases. Cytology underestimated the severity of the lesion in nine per cent while colposcopy underestimated the lesion in 7.2 per cent (False negative rate). In 13.8 per cent of cases colposcopy overestimated the lesion (False positive rate). The cone biopsy rate in this series was 30 per cent. We conclude that since colposcopy shows excellent correlation with histopathology, it will be a useful tool to reduce cone biopsy rates, particularly in younger women in the child-bearing age group. 相似文献
74.
A Picture Archiving and Communication System (PACS) was installed in the Medical Intensive Care Unit of the Hospital of the University of Pennsylvania. For one year, 8 week periods of FILM ONLY usage were alternated with 8 week periods of PACS OR FILM usage. The time interval between obtaining portable chest images and taking image dependent actions decreased when the PACS was used, however, about 40% of the action decisions were made without a radiologist's consultation. Only 5% of action decisions were made without consultation during the FILM ONLY periods. A new clinical study for measuring diagnostic accuracy and efficiency as well as communication patterns is described. 相似文献
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Mukund Joshi MD FAMS Karthik Ganesan DNB Harsha Navani Munshi DNB Subramania Ganesan MD Ashwin Lawande DNB 《Seminars in Ultrasound, CT and MRI》2008,29(2):72-97
Current advancements in imaging technology, especially three-dimensional/four-dimensional ultrasound and contrast-enhanced imaging, have increased the diagnostic yield of adnexal masses. The benefit of ultrasound is the characterization of an adnexal mass, suggesting the probable etiology of the mass. Masses may be divided as solid, cystic, or complex. It is predominantly the solid and complex masses that need a thorough evaluation. The role of color-flow imaging is now gaining importance and criteria for distinguishing between benign and malignant masses are often possible. Availability of a scoring system enables the differentiation of small adnexal masses. Several benign lesions may present as complex masses but can be distinguished and diagnosed on sonography. The availability of 3D ultrasound has been of great use to understand spatial relations and vascular morphology. Sonography allows a more detailed assessment of morphologic features of an adnexal mass. With a benign-appearing adnexal mass on sonography, the need for any further diagnostic tests is often obviated. 相似文献
79.
Lateral resolution in elastography 总被引:2,自引:0,他引:2
The factors that control the lateral resolution in elastography were investigated using a simulation study. The lateral resolution was estimated from the simulated axial strain elastograms as the smallest measurable distance between two equally stiff lesions embedded in a homogeneously softer background. The lesions were symmetrically positioned lateral to the center of the target, at the focus of the transducer. Ultrasound (US) systems with different transducer frequencies, bandwidths and f-numbers were simulated. The effects of the ultrasonic parameters, the lateral spacing between adjacent echo signals, the cross-correlation window length, the lesion/background elastic contrast and the lateral motion of scatterers on the estimated lateral resolution were investigated. The results show that the lateral resolution in elastography is proportional to the beam width of the US system used to acquire the data, and is on the same order as the sonographic lateral resolution. 相似文献
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