COMPARISON OF METAL ARTEFACTS FOR DIFFERENT DUAL ENERGY CT TECHNIQUES

Area of Science:

• Medical Imaging
• Radiology
• Materials Science

Background:

• Dual-energy computed tomography (DECT) is crucial for imaging metallic implants.
• Metal artifacts in CT scans can degrade image quality and diagnostic accuracy.
• Simulating bilateral hip prostheses helps evaluate imaging techniques in challenging scenarios.

Purpose of the Study:

• To compare dual-source (DS) and fast kV-switching (FKS) DECT techniques.
• To evaluate the impact of metal artifact reduction (MAR) on image quality.
• To assess CT number accuracy and material depiction in the presence of metallic hip prostheses.

Main Methods:

• A phantom with material inserts and lateral titanium or stainless steel inserts was used.
• DS and FKS DECT techniques were employed, with and without MAR.
• Virtual monoenergetic images were analyzed for CT number accuracy and material depiction.

Main Results:

• Streak artifacts were observed between metal inserts, more severe for stainless steel than titanium.
• Artifact severity and CT number accuracy were energy-dependent (keV) for both DECT techniques.
• FKS DECT demonstrated higher accuracy for CT numbers and external diameter of metal inserts compared to DS DECT.

Conclusions:

• FKS DECT provides more accurate imaging of hip prostheses than DS DECT.
• MAR improves accuracy within streak artifacts but can decrease accuracy outside them.
• Photon energy selection is critical for optimizing DECT imaging of metallic implants.