In CT, the attenuated radiation is measured by what?

In CT, the attenuated radiation is measured by what?

• A. Scintillation Crystals
• B. Geiger Counters
• C. Detectors
• D. Photodiodes

Answer: (C)

In CT, the amount of X-ray radiation that makes it through the patient (the attenuated beam) is captured by detectors. The detector array sits opposite the X-ray source and measures the transmitted photons, converting that radiation into an electrical signal that can be used to reconstruct the image. Modern detectors typically combine a scintillation crystal layer, which converts X-rays to light, with photodiodes or similar sensors that turn that light into an electrical signal; some designs use different direct-conversion materials. This signal from all detectors across many angles provides the data the computer uses to compute the internal structure. Geiger counters aren’t suited for CT because they aren’t designed for the high dynamic range and rapid, continuous data needed for imaging. Scintillation crystals and photodiodes are components within the detector system, but the measurement itself is performed by the detector assembly as a whole.

In CT, the amount of X-ray radiation that makes it through the patient (the attenuated beam) is captured by detectors. The detector array sits opposite the X-ray source and measures the transmitted photons, converting that radiation into an electrical signal that can be used to reconstruct the image. Modern detectors typically combine a scintillation crystal layer, which converts X-rays to light, with photodiodes or similar sensors that turn that light into an electrical signal; some designs use different direct-conversion materials. This signal from all detectors across many angles provides the data the computer uses to compute the internal structure.

Geiger counters aren’t suited for CT because they aren’t designed for the high dynamic range and rapid, continuous data needed for imaging. Scintillation crystals and photodiodes are components within the detector system, but the measurement itself is performed by the detector assembly as a whole.