Internal or in-scan validation: a method to assess CBCT and MSCT gray scales using a human cadaver

Area of Science:

• Radiology
• Medical Imaging
• Dental Imaging

Background:

• Cone beam computed tomography (CBCT) and multislice computed tomography (MSCT) are advanced imaging techniques.
• Quantifying tissue density is crucial for accurate diagnosis and treatment planning.
• The Hounsfield unit (HU) scale is a standard for measuring radiodensity in CT scans.

Purpose of the Study:

• To evaluate the applicability of CBCT and MSCT for quantifying tissue density.
• To determine if the Hounsfield unit scale is applicable to CBCT imaging.
• To compare gray scale values between CBCT and MSCT in the mandible region.

Main Methods:

• A clinical MSCT scanner and CBCT were used to image a phantom with mandible region slices.
• Effective energy-adjusted photon beam attenuation references were employed.
• Gray values from both scanner datasets were compared using linear profile lines.

Main Results:

• A strong correlation was found between the gray values from CBCT and MSCT scans.
• Position-dependent differences were quantified, validating the imaging methods.
• The internal validation process demonstrated consistency between the two imaging modalities.

Conclusions:

• An internal, in-scan validation method can estimate and potentially compensate for protocol differences between MSCT and CBCT.
• This validation approach can guide users when expecting deviations in imaging protocols.
• CBCT shows potential for accurate tissue density quantification comparable to MSCT.