Cranial CT artifacts and gantry angulation

Area of Science:

• Radiology
• Medical Imaging
• Neuroimaging

Background:

• Computed tomography (CT) of the brain is crucial for diagnosing neurological conditions.
• Standard scanning parallel to the canthomeatal line can lead to streak artifacts from bone-induced beam hardening.
• These artifacts compromise the evaluation of the brain stem and posterior fossa structures.

Purpose of the Study:

• To investigate methods for reducing bone-induced streak artifacts in brain CT scans.
• To evaluate the effectiveness of altering gantry angulation in minimizing posterior fossa artifacts.
• To determine the optimal gantry inclination for improved brain stem and neighboring structure visualization.

Main Methods:

• Phantom study and clinical trial were conducted.
• Scans were performed with varying gantry angulations, including a 5-degree inclination below the Reid baseline.
• Slice thickness and exposure parameters were varied to assess their impact on artifacts.

Main Results:

• A specific gantry angulation significantly reduced streak artifacts.
• An inclination of 5 degrees below the Reid baseline was found to be effective in minimizing interpetrous artifacts.
• Variations in slice thickness and exposure parameters did not significantly affect the posterior fossa artifact.

Conclusions:

• Altering gantry angulation is an effective strategy to reduce bone-induced beam hardening artifacts in brain CT.
• A 5-degree gantry tilt below the Reid baseline is recommended for minimizing artifacts in the posterior fossa.
• This technique can improve the diagnostic quality of neuroimaging studies, particularly for brain stem evaluation.