Which would lead to an increase in patient dose?

Which would lead to an increase in patient dose?

• A. Decreased Fill Factor
• B. Increased DEL Size
• C. Decreased Storage Capacitor
• D. Decreased TFT Gate

Answer: (A)

The key idea is how detector efficiency affects the exposure needed to get a usable image. A decreased fill factor means a smaller fraction of each detector element is sensitive to x-rays, leaving more dead space. That lowers the amount of signal generated for the same incoming dose, so the system has to be exposed to a higher dose to achieve the same image quality and brightness. Other options don’t inherently force more dose: increasing detector element size reduces spatial resolution but doesn’t automatically require more exposure; decreasing the storage capacitor or the TFT gate size mainly affect dynamic range, charge storage, or readout, not the amount of exposure needed to produce a satisfactory image.

The key idea is how detector efficiency affects the exposure needed to get a usable image. A decreased fill factor means a smaller fraction of each detector element is sensitive to x-rays, leaving more dead space. That lowers the amount of signal generated for the same incoming dose, so the system has to be exposed to a higher dose to achieve the same image quality and brightness.

Other options don’t inherently force more dose: increasing detector element size reduces spatial resolution but doesn’t automatically require more exposure; decreasing the storage capacitor or the TFT gate size mainly affect dynamic range, charge storage, or readout, not the amount of exposure needed to produce a satisfactory image.