[A Simple Method for Computationally Generating Metal Artifacts in CT Images for Treatment Planning: A Pilot Phantom...

Area of Science:

• Medical Imaging
• Radiation Oncology
• Computational Science

Background:

• Metal artifacts in computed tomography (CT) images reduce radiation therapy dose calculation accuracy.
• Current clinical practice involves manual contouring and assigning fixed CT numbers to artifacts, requiring impractical pre- and post-metal insertion imaging for validation.
• Accurate artifact simulation is crucial for validating and improving clinical CT image processing techniques.

Purpose of the Study:

• To develop a computationally efficient method for generating realistic metal artifacts in clinical CT images.
• To provide a practical alternative to physical imaging for validating artifact correction procedures in radiation therapy planning.
• To enhance the accuracy of dose calculations in radiation therapy by addressing metal artifact challenges.

Main Methods:

• A metal artifact simulation technique using a metal-free clinical CT image.
• Replacing CT numbers in a designated region with a high value to simulate metal.
• Generating a sinogram, modifying metal region data, and reconstructing an artifact-inclusive image using filtered back projection.

Main Results:

• The computationally generated artifacts exhibited dark and bright bands, closely resembling actual metal artifacts.
• Quantitative analysis showed good agreement between CT numbers in simulated and actual artifact regions.
• The proposed method successfully generated additional metal artifacts on clinical images.

Conclusions:

• The developed method effectively generates metal artifacts computationally on clinical CT images.
• This technique offers a valuable tool for validating clinical procedures for handling metal artifacts in radiation therapy.
• The simulation method can potentially improve the accuracy and reliability of radiation therapy planning.