Signal-to-noise (SNR) is increased when which condition is used?

Signal-to-noise (SNR) is increased when which condition is used?

• A. Scatter is present
• B. Excessive kVp is used
• C. Grids are utilized
• D. Patient receives optimal dose

Answer: (C)

Scatter adds unwanted background that dulls contrast and contributes to noise, so reducing scatter boosts the brightness consistency of the true signal relative to random fluctuations. A grid works by absorbing a portion of scattered photons before they reach the image receptor, which lowers background fog and improves the signal-to-noise balance. Because some primary photons are also absorbed by the grid, exposure may need to be increased to keep the signal strong, but with proper technique the overall SNR improves. In contrast, the presence of scatter, using excessively high kVp, or relying on dose alone without addressing image quality will not inherently raise SNR. So using a grid is the condition that increases SNR.

Scatter adds unwanted background that dulls contrast and contributes to noise, so reducing scatter boosts the brightness consistency of the true signal relative to random fluctuations. A grid works by absorbing a portion of scattered photons before they reach the image receptor, which lowers background fog and improves the signal-to-noise balance. Because some primary photons are also absorbed by the grid, exposure may need to be increased to keep the signal strong, but with proper technique the overall SNR improves. In contrast, the presence of scatter, using excessively high kVp, or relying on dose alone without addressing image quality will not inherently raise SNR. So using a grid is the condition that increases SNR.