Which of the following is a potentially negative consequence of an increased anode angle?

Which of the following is a potentially negative consequence of an increased anode angle?

• A. Increased effective focal spot
• B. Decreased effective focal spot
• C. No change in focal spot
• D. Decreased heat capacity

Answer: (A)

Increasing the anode angle makes the effective focal spot larger. The actual focal spot on the anode remains the same size, but as the anode is tilted, the projection of that spot onto the imaging plane becomes elongated, so the effective focal spot grows. A larger effective focal spot reduces image sharpness because the geometric blur increases, which is a negative for spatial resolution. While a bigger angle can spread heat over a larger area of the anode and may allow higher exposures, the downside is the loss of sharpness due to the larger focal spot.

Increasing the anode angle makes the effective focal spot larger. The actual focal spot on the anode remains the same size, but as the anode is tilted, the projection of that spot onto the imaging plane becomes elongated, so the effective focal spot grows. A larger effective focal spot reduces image sharpness because the geometric blur increases, which is a negative for spatial resolution. While a bigger angle can spread heat over a larger area of the anode and may allow higher exposures, the downside is the loss of sharpness due to the larger focal spot.