Which technique is employed to mitigate the "star" effect during tomographic reconstruction?

Which technique is employed to mitigate the "star" effect during tomographic reconstruction?

• A. Iterative reconstruction
• B. Filtered back projection
• C. Fourier transform
• D. Adaptive smoothing

Answer: (B)

The technique that is used to mitigate the "star" effect during tomographic reconstruction is iterative reconstruction. This approach enhances image quality by improving noise performance and reducing artifacts that can occur during the image reconstruction process. In tomographic imaging, particularly in techniques like SPECT and PET, the "star" artifact arises from the shape and orientation of the data used in reconstruction, specifically when using filtered back projection. Filtered back projection can lead to these artifacts due to its nature of applying a filter to the raw data before projecting it back into the image space. Iterative reconstruction, on the other hand, addresses these limitations by making multiple passes over the data and refining the image iteratively. It allows for better modeling of the data collection process and provides a way to update the image estimate based on the measured data and any prior knowledge about the expected image characteristics. This results in improved image quality and helps to effectively reduce artifacts, including the "star" effect. Adaptive smoothing is a separate technique that can assist in noise reduction but does not specifically target the “star” effect like iterative reconstruction does. Meanwhile, Fourier transform is a mathematical technique used in various imaging modalities but is not directly responsible for addressing the artifacts associated with tomographic reconstruction.

The technique that is used to mitigate the "star" effect during tomographic reconstruction is iterative reconstruction. This approach enhances image quality by improving noise performance and reducing artifacts that can occur during the image reconstruction process.

In tomographic imaging, particularly in techniques like SPECT and PET, the "star" artifact arises from the shape and orientation of the data used in reconstruction, specifically when using filtered back projection. Filtered back projection can lead to these artifacts due to its nature of applying a filter to the raw data before projecting it back into the image space.

Iterative reconstruction, on the other hand, addresses these limitations by making multiple passes over the data and refining the image iteratively. It allows for better modeling of the data collection process and provides a way to update the image estimate based on the measured data and any prior knowledge about the expected image characteristics. This results in improved image quality and helps to effectively reduce artifacts, including the "star" effect.

Adaptive smoothing is a separate technique that can assist in noise reduction but does not specifically target the “star” effect like iterative reconstruction does. Meanwhile, Fourier transform is a mathematical technique used in various imaging modalities but is not directly responsible for addressing the artifacts associated with tomographic reconstruction.