CT scan artifact

 A CT scan artifact refers to any distortion or error in a CT (Computed Tomography) image that can mislead or obscure the interpretation of the scan. These artifacts can arise from various sources and are often categorized based on their causes:

1. Patient-Related Artifacts:

   • Motion Artifacts: Caused by patient movement during the scan, leading to streaks or blurring.
   • Beam-Hardening Artifacts: Occur when x-rays pass through dense materials, like bones, causing dark streaks or shading.

2. Scanner-Related Artifacts:

   • Ring Artifacts: Caused by faulty detector elements, appearing as concentric rings.
   • Streak Artifacts: Often due to metallic objects (e.g., dental fillings, implants) within the body, which create bright streaks.

3. Physics-Related Artifacts:

   • Partial Volume Artifacts: Occur when different tissues are averaged within a single voxel, leading to incorrect density readings.
   • Photon Starvation: When x-rays are heavily attenuated by dense structures, resulting in poor image quality in certain areas.

4. Reconstruction Artifacts:

   • Aliasing Artifacts: Result from undersampling during the scan, leading to misregistration of structures.
   • Helical Artifacts: Specific to helical (spiral) CT, these can appear due to the pitch and interpolation method used during image reconstruction.

Preventing and managing these artifacts typically involves a combination of proper patient positioning, use of artifact reduction algorithms, adjusting scan parameters, and sometimes using alternative imaging modalities.