Radiographic Grid.pptx

Radiographic grids are devices designed to minimize scatter radiation while preserving the primary X-rays that contribute to image formation.

1. Radiographic Grid Presenter: Dr. Dheeraj Kumar MRIT, Ph.D. (Radiology and Imaging) Assistant Professor Medical Radiology and Imaging Technology School of Health Sciences, CSJM University, Kanpur 04/09/2023 Radiographic Grid By- Dr. Dheeraj Kumar 1

2. Introduction Radiographic grids are devices designed to minimize scatter radiation while preserving the primary X-rays that contribute to image formation. They consist of alternating radiopaque lead strips and interspace material, creating a matrix that selectively allows primary radiation to pass through while absorbing scattered radiation. 04/09/2023 Radiographic Grid By- Dr. Dheeraj Kumar 2

3. W orking P rinciple The working principle of radiographic grids lies in their ability to absorb scattered radiation. When X-rays pass through the patient, some are scattered in various directions. The lead strips in the grid absorb a significant portion of this scattered radiation. As a result, the primary X-rays, necessary for image formation, remain predominant. 04/09/2023 Radiographic Grid By- Dr. Dheeraj Kumar 3

4. History The mid-20th century marked a turning point with the introduction of the first radiographic grids. Pioneers like Hollis Potter and Gustave Bucky recognized the need to tackle the issue of scatter and explored innovative solutions. In 1904, Bucky's invention of the grid, known as the "Bucky Grid," was a pivotal step toward achieving clearer images. 04/09/2023 Radiographic Grid By- Dr. Dheeraj Kumar 4

5. Types of Grids Parallel Grids: These have lead strips running parallel to each other and are well-suited for examinations with minimal divergence of X-ray beams. Focused Grids: In these grids, lead strips are angled to match the divergence of X-rays, reducing the risk of grid cut-off and allowing for greater latitude in patient positioning. 04/09/2023 Radiographic Grid By- Dr. Dheeraj Kumar 5

6. Moving grids Moving grids are innovative devices designed to counteract the challenges associated with stationary grids. They incorporate a mechanism that introduces controlled motion to the grid during the X-ray exposure. This motion helps minimize the impact of grid lines, grid cut-off, and the Moiré effect on the final radiographic image. 04/09/2023 Radiographic Grid By- Dr. Dheeraj Kumar 6

7. Scatter Radiation and Its Effects Scatter Radiation Defined: Scatter radiation refers to secondary X-rays that result from the interaction of primary X-rays with patient tissues. It contributes to decreased image quality. Impact on Image Quality: Scatter radiation reduces image contrast, blurs fine details, and affects overall diagnostic accuracy, making its control vital. 04/09/2023 Radiographic Grid By- Dr. Dheeraj Kumar 7

8. Components of Radiographic Grids Radiopaque Strips: Radiopaque lead strips within the grid absorb scattered radiation, preventing it from reaching the image receptor. Interspace Material: Interspace material, often made of aluminum or plastic, allows primary X-rays to pass through, contributing to the formation of the radiographic image. Grid Ratio: Grid ratio is the ratio of the height of the lead strip to the width of the interspace material. It determines scatter absorption efficiency and image quality. 04/09/2023 Radiographic Grid By- Dr. Dheeraj Kumar 8

9. Grid Ratio and Image Quality Grid Ratio Explained: Grid ratio directly impacts image quality. A higher grid ratio increases scatter absorption, enhancing image contrast but also requiring higher exposure factors. Choosing the Right Ratio: Selecting the appropriate grid ratio depends on the imaging scenario. Higher ratios are favoured for specialized imaging while lower ratios balance dose and image quality. 04/09/2023 Radiographic Grid By- Dr. Dheeraj Kumar 9

10. Grid Frequency and Detail Understanding Grid Frequency: Grid frequency refers to the number of lead strips per unit length (usually per inch or centimeter ). Higher grid frequency reduces visibility of grid lines on the image. Influence on Image Detail: Higher grid frequency results in improved image detail and clarity, making it ideal for capturing fine anatomical structures. 04/09/2023 Radiographic Grid By- Dr. Dheeraj Kumar 10

11. Grid Alignment and Focusing Distance Importance of Proper Alignment: Accurate alignment of the grid and central X-ray beam is essential to prevent grid cut-off and ensure consistent image quality across the entire field. Impact of Focusing Distance: Maintaining the recommended focusing distance between the grid and the patient helps optimize image quality by minimizing distortion and artifacts. 04/09/2023 Radiographic Grid By- Dr. Dheeraj Kumar 11

12. Grid Cut-off and Errors Grid Cut-off Explained: Grid cut-off occurs when improper positioning or incorrect technique factors lead to a reduction in primary radiation reaching the image receptor. Common Errors: Off- center grids result from misalignment of the X-ray tube and grid, while upside-down grids lead to grid cutoff due to reversed lead strip orientation. 04/09/2023 Radiographic Grid By- Dr. Dheeraj Kumar 12

13. Advancements in Grid Technology Moving Grids: Moving grids introduce dynamic motion during exposure to minimize the appearance of grid lines on the image, enhancing image quality. Stationary Grids with Software Correction: Stationary grids, coupled with software-based corrections, compensate for grid-related artifacts, resulting in cleaner images. 04/09/2023 Radiographic Grid By- Dr. Dheeraj Kumar 13

14. Digital Radiography and Grids Grid Considerations in Digital Imaging: Digital imaging systems require adjustments due to increased grid absorption, necessitating modifications in technique factors. Importance of Grids in Digital Imaging: Despite advancements in digital technology, grids remain essential for improving image quality and diagnostic accuracy. 04/09/2023 Radiographic Grid By- Dr. Dheeraj Kumar 14

15. Practical Application and Care Proper Positioning: Accurate grid positioning ensures that the central X-ray beam is aligned, minimizing artifacts and maintaining image quality. Collimation and Field Coverage: Proper collimation not only reduces patient exposure to radiation but also ensures the image is well- centered and high in quality. 04/09/2023 Radiographic Grid By- Dr. Dheeraj Kumar 15

16. References Bushong , S. C. (2018). Radiologic Science for Technologists: Physics, Biology, and Protection. Mosby. Fauber , T. L. (2019). Radiographic Imaging and Exposure. Elsevier Health Sciences. Carlton, R. R., & Adler, A. M. (2016). Principles of Radiographic Imaging: An Art and A Science. Cengage Learning. Clark, K. R., Bushong , S. C., & Slovis , T. L. (2019). Essentials of Radiographic Physics and Imaging. Elsevier Health Sciences. 04/09/2023 Radiographic Grid By- Dr. Dheeraj Kumar 16

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