How to Recognize a Bad Grid Moire Pattern: The image on the right. It’s created by the grid and detector interacting, like when you take a picture of a TV screen. Seeing a moire pattern means grid suppression is not working. This could be a software issue, or could be because the grid [...]
What is a Grid? A grid, fully named an “X-Ray Antiscatter Grid," is comprised of alternating lines of lead and another, much more X-ray transparent material, that is put directly in front of the detector or film. The purpose of them is to remove x-rays that have scattered and are not moving in [...]
When evaluating the quality and performance of a mammography grid, it is difficult to perform a quantitative analysis. As a general method, the first step is to measure and compare the difference in film density (or detector exposure) across the entire area. The second step is to check the x-ray quality with a [...]
According to the American Cancer Society 2007 Global Facts and Figures, breast cancer is the first or second most commonly diagnosed form of cancer in many of the largest medical markets. According to the National Cancer Institute, more than 270,000 new cases are expected in the United States this year. Additionally, breast cancer [...]
Antiscatter grids are considered an indispensable tool to improve image contrast and even decrease imaging doses if they are properly selected and installed specifically for the imaging system. However, the most critical problem remaining as an obstacle for their successful use in digital x-ray imaging is probably the the observation of the grid [...]
While most anti-scatter grids are produced manually, JPI-2100 grids are fabricated based on the semiconductor process. This creates far more uniformity between grid lines than a hand assembled grid. The dose distribution after transmission through a JPI-2100 grid homogeneous. Therefore, its mammography image is much cleaner, with equal exposure across the entire image. [...]
JPI has developed high precision carbon-interspaced antiscatter grids to be suitable for Digital Radiography (DR) by adopting a precise sawing process. For systematic evaluation of the grid performance, we prepared several sample grids having different grid frequencies (4.0 to 8.5 lines/mm) and grid ratios (5:1 to 10:1) and established a well-controlled test condition [...]
Since the development of the antiscatter grid in 1913, a major problem has been the resulting lines that can appear in the x-ray image. This critical defect created a risk of misdiagnosis by physicians. In 1920, Dr. Hollis Potter devised a solution for this problem by finding a movement patter that would eliminate [...]
When two grids have the same specifications, why are their transmissions different? The reason is that the interspace width and height is different. As the x-ray interacts with different amounts of lead and aluminum, its attenuation changes. Do standard tests cover everything with regard to grid quality? Grid characteristics change with the x-ray [...]
A very difficult problem for recent high-resolution digital x-ray detectors is that, as resolution goes up, so does the difficulty of eliminating grid artifacts from the image. This is a problem for mammography systems in particular, where resolutions are much higher than in general radiography. In this article, we will discuss mathematical methods [...]
