• Home • Catalog • About Us • New Products • Search • Contact Us • Careers • See Us at... • Services • Brochures •

Antiscatter Grids - An Essential Component of Image Quality - Part 1


by Dr. Frank Ranallo, PhD

A grid may only comprise about 1% of the cost of an imaging system, but its importance to system performance is much greater than its cost might indicate. Properly selected and installed high quality grids can dramatically improve image quality and even decrease patient dose. However grids are often woefully neglected both in their initial specification and in the testing of their performance.

In part 2 of this article I will discuss some of the important tests that should be performed with grids to verify their quality and proper alignment. In this article I will discuss some of the properties of grids and some of the most common examples of how things can go wrong in grid selection and use.

Grids are made up of regularly spaced thin septa of lead separated by interspaces of aluminum or fiber. An 18 by 18 inch grid will contain many hundreds of lead septa, each 18 inches long but less than 1 cm high. The first important properly of a grid is the orientation or direction of the grid lines (the direction of the long dimension of the grid strips). Read the full article here.

Dr Frank Ranallo, PhD, DACR is Associate Professor of Medical Physics and Radiology at the University of Wisconsin Medical School

 

New! Gammex RBA-6 - Daily Output and Symmetry Monitor

- The RBA-6 is designed for daily monitoring of output, symmetry, energy and flatness of radiation therapy treatment Gammex RBA-6machines.  The multi-detector instrument provides users with a simple, rapid system for checking multiple energies on different machines.  The “touch” screen entry of commands makes set-up and customization quick and simple.

The Windows™ -based control software tracks the name, radiation units, energy, build-up material added, gantry angle, SSD, number of exposures and MU/exposure for each measurement.  User-determined warning points can be set to provide information on “hot” and “warm” areas based on the parameters established by the physicist.  Data can be transferred via Flashcards to standard Word-processor and/or spreadsheet applications.

The RBA-6 can be expanded economically with the optional Diode Dosimetry Software and diode detectors to perform 5-channel diode dosimeter.  This allows the instrument to have double use: 1) as a check for daily beam output and 2) as a dosimeter! 


Gammex 467 - Tissue Characterization Phantom

Gammex 467- The 467 phantom by Gammex provides users with a faster and easier method for tissue variation corrections during isodose treatment planning.  Correlation of tissue electron densities with CT number (Hounsfield Units, HU) is necessary for reliable dose calculation.  The phantom offers a wide range of densities in the bone and tissue rods provided.   Its Solid Water™ core provides the long term reliability you have experienced with other Gammex phantoms for years.

Data obtained using the phantom can easily be transferred to your treatment planning system to correct for tissue inhomogeneities.

An optional Titanium insert rod can expand the range and utility of the phantom even further.

 

Comments to webmaster@gammex.com about this web site are welcome. Copyright © 2008 Gammex Inc.  All Rights Reserved Last modified: 04/03/08  Privacy Statement | Legal Info |