1. What is Grid Ratio?

Grid Ratio is a key parameter in radiography that describes the relationship between the height of the lead strips (h) and the distance between them (d) in an anti-scatter grid. It affects the grid's performance in improving image contrast by reducing scattered radiation.

2. How Does the Calculator Work?

The calculator uses the Grid Ratio formula:

Where:

• \( h \) — Height of lead strips (mm)
• \( d \) — Width of interspace between lead strips (mm)

Explanation: The grid ratio determines how effectively the grid removes scattered radiation while allowing primary radiation to pass through.

3. Importance of Grid Ratio

Details: Higher grid ratios provide better scatter rejection but require more precise alignment and higher exposure factors. Common grid ratios range from 5:1 to 16:1 in medical radiography.

4. Using the Calculator

Tips: Enter the lead height (h) and interspace width (d) in millimeters. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What are typical grid ratio values?
A: Common grid ratios are 5:1, 6:1, 8:1, 10:1, 12:1, and 16:1, with higher ratios providing better scatter rejection.

Q2: How does grid ratio affect image quality?
A: Higher ratios improve contrast by better scatter rejection but require increased exposure and are more sensitive to alignment errors.

Q3: What's the relationship between grid ratio and Bucky factor?
A: Higher grid ratios generally have higher Bucky factors, meaning more radiation is needed to achieve the same image density.

Q4: When should I use a higher grid ratio?
A: Higher ratios are preferred for thicker body parts or higher kVp techniques where scatter production is greater.

Q5: What are the limitations of grid ratio?
A: Very high grid ratios may cause cutoff artifacts if not perfectly aligned and require significantly higher patient dose.