Automated Method for Evaluation of Z-axis Laser Alignment Accuracy using the Siemens Computed Tomography Phantom

Area of Science:

• Medical Imaging
• Quality Control
• Computed Tomography (CT)

Background:

• Accurate z-axis laser alignment is crucial for precise image acquisition in CT scanners.
• Manual alignment checks can be time-consuming and prone to subjective errors.

Purpose of the Study:

• To develop an automated system for measuring z-axis laser alignment in CT.
• To evaluate the accuracy and reliability of the automated system using a Siemens CT phantom.

Main Methods:

• Image segmentation of the CT phantom to determine its radius.
• Analysis of pixel value profiles along engraved notches to measure distance.
• Conversion of pixel distance to millimeters for z-axis displacement (d) calculation.

Main Results:

• High correlation (R > 0.99) between automated and set z-axis displacement values.
• Automated measurements showed minimal differences (0.14-0.26 mm) compared to manual measurements across various slice thicknesses.
• The system demonstrated reliability for z-axis displacement measurements from 0 to 9 mm.

Conclusions:

• The developed automated software provides objective and accurate z-axis laser alignment measurements.
• This automated approach can enhance the quality control process for CT scanners.
• The system has the potential to improve diagnostic accuracy by ensuring proper laser alignment.