Computed Tomography Technologist Practice Exam 2025 - Free CT Technologist Practice Questions and Study Guide

Beam hardening is a phenomenon that occurs when low-energy photons in an X-ray beam are absorbed more readily by the tissues being imaged than high-energy photons. As the beam passes through dense materials (such as bone or metal), the average energy of the transmitted beam increases—hence "hardening." This results in a skewed representation of the tissues within the scanned area.

The primary consequence of beam hardening is that it leads to inaccurate image representation. The increased average photon energy can cause visible artifacts in the resulting images, including dark bands or streaks, which distort the actual composition and density of the structures being imaged. For instance, in a CT scan, this may manifest as an underestimation of the density of areas that have high atomic number, like bone, leading to misdiagnoses or inappropriate treatment decisions.

Understanding that beam hardening can cause these discrepancies is crucial for technologists, as it highlights the importance of considering this effect when evaluating image quality and interpreting diagnostic results. Adjusting scanning parameters and using calibration techniques can help mitigate these undesirable effects, ultimately improving the accuracy of the imaging process.