![]() Grid, but it is positioned above or below the convergent The target of the X-ray tube is correctly centered to the.Loss of primary radiation across the entire When a linear grid is tilted, there is uniform 3 factors affect the magnitude of cut off from lateral.Grid, producing a uniformly light radiograph. Uniform loss of radiation over the entire surface of the.When the X-ray tube is positioned lateral to theĬonvergent line but at the correct focal distance.The higher the grid ratio,narrower the exposed area.The center of the film with no exposure at the periphery. Severe peripheral cut off with a dark band of exposure in When a focused grid is used upside down, there is. ![]() 4 SITUATIONS THAT PRODUCE GRID CUT OFF :Ģ.Amount of cut off is always greatest with high ratio grids.Thicker than the width of the interspaces. Cut off is complete and no primary radiation reaches theįilm when the projected images of the Lead strips are.Primary beam and the Lead foil strips of the grid. Result of a poor geometeric relationship between the.The Lead strips are projected wider than they would be Loss of primary radiation that occurs when the images of.More closely related to the Lead content of the grid than.Measure of the grid’s ability to improve contrast which is.Ratio of the contrast with a grid to the contrast without a.ī= INCIDENT RADIATION / TRANSMITTED RADIATION Unlike primary transmission, Bucky factor indicates theĪbsorption of both primary and secondary radiation.Measure of the Grid’s ability to absorb scatter radiation.Increased when the change from grid to a non grid Indicates the amount of exposure factors that should be.Transmitted radiation passing through the grid. Ratio of the incident radiation on the grid to the.Made after removal of the grid to determine the intensity Made with the grid in place to determine the intensity ofĢ. Measurement of the percentage of primary radiationġ.Interspaces and dividing this sum into 1. LINES PER INCH : Number of Lead strips per inch ofĬalculated by adding the thickness of the Lead strips and Can only be used effectively with either very small Xray Focused at infinity so they do not have a convergent line Lead strips are parallel when viewed in cross section. Line focused grids converge at a line in space calledĬrossed Grids converge in a point in space calledįOCAL DISTANCE : Perpendicular distance between the Grid made up of lead strips that are slightly angled so that ![]() Grid ratio of two crossed grids is equal to the sum of theĬannot be used with oblique techniques requiring Made of two superimposed linear grids that have the same Tube along the length of the Grid without loss of primary Major advantage is that they allow us to angle the X-ray The Lead strips are parallel to each other in their
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