Analysis of intensity variability in multislice and cone beam computed tomography

Area of Science:

• Radiology
• Medical Imaging
• Dental Imaging

Background:

• Cone beam computed tomography (CBCT) is increasingly used in dentistry and radiology.
• Accurate density assessment is crucial for diagnostic interpretation.
• Comparison with multislice computed tomography (MSCT) Hounsfield units (HU) is needed to validate CBCT's quantitative capabilities.

Purpose of the Study:

• To evaluate the variability of CBCT intensity values.
• To compare CBCT intensity values with MSCT Hounsfield units (HU).
• To assess the reliability of density assessments using CBCT images.

Main Methods:

• A quality control phantom was scanned using one MSCT scanner and five CBCT scanners.
• Repeated scans were performed on one CBCT scanner with varying positions.
• Image analysis involved registration to a mathematical model, with MSCT images serving as the reference.

Main Results:

• MSCT Hounsfield units (HU) demonstrated stable density profiles.
• CBCT imaging exhibited variable intensity values across density profiles.
• Phantom repositioning led to significant fluctuations in CBCT intensity values.

Conclusions:

• CBCT intensity values are not reliable for quantitative density assessment.
• Variability is influenced by the specific CBCT device, imaging parameters, and patient positioning.
• MSCT HU provides a more stable and reliable reference for density measurements.