Method of Individual Adjustment for 3D CT Analysis: Linear Measurement

Area of Science:

• Medical Imaging
• Radiology
• Biomedical Engineering

Background:

• Accurate 3D analysis of cephalometric data is crucial for surgical planning.
• Standard 3D CT measurements can be imprecise due to variations in scan parameters.
• Length-based measurements are fundamental in cephalometric examinations.

Purpose of the Study:

• To regularize measurement values in 3D CT reconstructed images for higher-precision 3D analysis.
• To focus on length-based 3D cephalometric examinations.
• To develop a method for obtaining accurate real physical values from Picture Archiving and Communication System (PACS) measurements.

Main Methods:

• Linear distances on skull models were measured using Vernier calipers (real values).
• 3D CT scans of models were performed with varying tilt angles, and measurements were taken from PACS.
• PACS measurements were adjusted using Display Field of View (DFOV) values and compared to real values.

Main Results:

• No significant correlation was found between real values and unadjusted PACS measurements concerning tilt angle.
• Significant correlations (p < 0.001) were observed between real values and DFOV-adjusted PACS measurements.
• A correlation expression was derived to convert PACS measurements to real physical values.

Conclusions:

• DFOV adjustment is essential for accurate length-based 3D cephalometric analysis from CT scans.
• Precise preoperative length confirmation and postoperative improvement analysis are achievable.
• This method aids in facial bone surgery symmetry correction.