PubMed · 6919499
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
I I Rushakov. 1982. [Computed tomography].. https://pubmed.ncbi.nlm.nih.gov/6919499/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
PURPOSE: To develop a portable software tool for fast computation of digitally reconstructed radiographs (DRR) with a friendly user interface and versatile image format and display options. To provide a means for interfacing with commercial and custom three-dimensional (3D) treatment planning systems. To make the tool freely available to the Radiation Oncology community. METHODS AND MATERIALS: A computer program for computing DRRs was enhanced with new features and rewritten to increase computational efficiency. A graphical user interface was added to improve ease of data input and DRR display. Installer, programmer, and user manuals were written, and installation test data sets were developed. The code conforms to the specifications of the Cooperative Working Group (CWG) of the National Cancer Institute (NCI) Contract on Radiotherapy Treatment Planning Tools. RESULTS: The interface allows the user to select DRR input data and image formats primarily by point-and-click mouse operations. Digitally reconstructed radiograph formats are predefined by configuration files that specify 19 calculation parameters. Enhancements include improved contrast resolution for visualizing surgical clips, an extended source model to stimulate the penumbra region in a computed port film, and the ability to easily modify the CT numbers of objects contoured on the planning computed tomography (CT) scans. CONCLUSIONS: The DRR tool can be used with 3D planning systems that lack this functionality, or perhaps improve the quality and functionality of existing DRR software. The tool can be interfaced to 3D planning systems that run on most modern graphics workstations, and can also function as a stand-alone program.
For economic reasons modern equipment which produces low to medium energy X-rays covers the whole range of beam qualities from traditional superficial to orthovoltage radiation qualities. A recent trend shows an increasing number of installations of orthovoltage units in the cancer therapy community in the last five years. The use of a single anode for accelerating voltages between 60 and 300 kVp leads to compromises with regards to beam flatness and symmetry in the anode/cathode direction of the Siemens Stabilipan II radiation beam. A perspex flattening filter was designed to improve these beam parameters of the 300 kVp radiation beam (HVT 4mm Cu) at 50 cm and 60 cm FSD using a diaphragm-mounted field defining device. The filter design correlates with focal spot characteristics of the beam. The use of the filter improves flatness and symmetry for all measured field sizes from 6 x 6 cm2 to 18 x 18 cm2 by up to 8% (flatness) and 7% (symmetry) respectively. No significant difference in the depth dose characteristic of the 300 kVp beam was found with and without the filter. The only modification in the planning procedures required is the use of an attenuation factor of 0.89 for the filter. The use of the filter improves the dose distribution in treatment of patients undergoing orthovoltage radiotherapy--in particular treatments with large field sizes such as for metastases in the spinal column.
Explore the source record for details and available documents.