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1.
Kumar U Albala DM 《Journal of endourology / Endourological Society》2000,14(10):779-85; discussion 785-6
Transperitoneal laparoscopic nephrectomy is performed much as originally described by Clayman and associates, although preoperative embolization of the kidney is no longer routine. Some surgeons use a hand-assisted technique, especially in difficult cases or when the organ is being removed intact, as in live-donor nephrectomy. 相似文献
2.
Fibrin glue applications in urology 总被引:1,自引:0,他引:1
Fibrin glue is used as a hemostatic and adhesive agent. Until recently, safety issues had delayed approval of the commercial
preparation in the United States. Fibrin glue has found several urologic applications, especially as an adhesive agent. It
has excellent potential in laparoscopic surgery, where conventional tissue approximation techniques are cumbersome and time-consuming.
Fibrin glue has also been used as a delivery vehicle for autologous cell transplantation and may play a major role in tissue
engineering techniques in the future. 相似文献
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4.
Finite-element method in electrical impedance tomography 总被引:1,自引:0,他引:1
E. J. Woo P. Hua J. G. Webster W. J. Tompkins 《Medical & biological engineering & computing》1994,32(5):530-536
In electrical impedance tomography (EIT), current patterns are injected into a subject and boundary voltages are measured
to reconstruct a cross-sectional image of resistivity distribution. Static EIT image reconstruction requires a computer model
of a subject, an efficient data-collection method and robust and fast reconstruction algorithms. The finite-element method
is used as the computer model. The paper describes the finite-element analysis software package developed, including an interactive
graphical mesh generator and fast algorithms for solving linear systems of equations using sparse-matrix and vector techniques.
Various models of irregularly shaped subjects are developed using mesh-design tools, including automatic mesh generation and
optimisation using the Delaunay algorithm. Even though the software package is customised for use in electrical impedance
tomography, it can be used for other biomedical research areas, such as impedance cardiography, cardiac defibrillation and
impedance pneumography. 相似文献
5.
Widespread integration of networking technology will change the hospital imaging environment, making computational, archiving, and film production services available to network-connected modalities. This change will be reflected in the designs of the image acquisition modalities themselves. A view of the future is presented in which the modalities depend on network-provided services, simplifying the modalities’ designs and making them more cost-effective. Achieving this view will require cooperative efforts by standards groups, PACS and modality manufactures, and hospital organizations.
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International Urology and Nephrology - 相似文献
8.
Investigators in nuclear medicine have long been in search of a practical method to increase the number of detected events in cardiac SPECT. A clinically practical method requires a simple data acquisition protocol, clinically acceptable reconstruction times, artifact levels near or below visual threshold, and the use of currently available cameras and computers. Towards this end, we have developed the Cardiofocal collimator, a variable-focus collimator for cardiac SPECT that increases the number of detected events from the heart by more than a factor of two compared to that of a parallel-hole collimator with equivalent resolution. In both the transverse and axial dimensions, the focusing is strongest at the centre of the collimator, and gradually relaxes to nearly parallel-hole collimation at the edge of the collimator. The variable-focus concept provides an increase in the number of counts from organs imaged near the centre of the collimator, where the heart will spend most of the time during a cardiac SPECT study, while adequately sampling enough of the background activity distribution to prevent truncation artifacts in the reconstructed images. Images are reconstructed in clinically acceptable times using a filtered backprojection reconstruction algorithm. The algorithm supports both full-scan (360 degrees) and short-scan (180 degrees plus the fan angle) acquisitions. The results of simulations and phantom studies are included to demonstrate the performance of the Cardiofocal collimator. 相似文献
9.
Glossary of molecular imaging terminology 总被引:5,自引:0,他引:5
10.
Collimator angulation error and its effect on SPECT 总被引:1,自引:0,他引:1
Angulation errors in collimator septa degrade tomographic resolution in SPECT due to mispositioning of events in the projection data. These errors should be small compared to other contributions to SPECT system resolution, such as intrinsic camera and collimator resolution, gantry alignment, and algorithmic smoothing. We describe a radioisotope technique to measure septal angulation errors over the entire collimator surface to +/- 0.05 degrees (RMS). A simple computer simulation is used to estimate a tolerance level, based on a 1% degradation in reconstructed resolution, of 0.25 degrees (RMS) and 0.6 degrees (max.) for collimator septal deviations. We also point out two methods for collimator linearity correction during SPECT reconstruction. 相似文献