Volumetric accuracy of cone-beam computed tomography

Area of Science:

• Radiology
• Medical Imaging
• Dental Technology

Background:

• Cone-beam computed tomography (CBCT) is crucial for dental imaging.
• Accurate volumetric measurements are essential for diagnosis and treatment planning.
• Understanding factors affecting CBCT accuracy is vital for reliable results.

Purpose of the Study:

• To evaluate how object shape and position influence CBCT volumetric accuracy.
• To determine the impact of varying tube voltage and current on scan accuracy.
• To assess the overall reliability of CBCT for volumetric measurements.

Main Methods:

• Fabrication of four geometric objects (cylinder, cube, pyramid, hexagon) with precise dimensions.
• Acquisition of CBCT images using an Alphard Vega Dental CT system.
• Analysis of volumetric accuracy using OnDemand 3D software, calculating volume error (VE) under different exposure settings.

Main Results:

• Mean volume error (VE) ranged from -4.47% to 2.35%.
• Object shape did not significantly correlate with VE.
• Object distance from the image center and tube voltage significantly impacted VE, while tube current did not.

Conclusions:

• The tested CBCT device demonstrated satisfactory volumetric measurement accuracy.
• High-resolution, low-dose serial scans may suffice for volume assessment.
• Findings offer guidance for optimizing CBCT protocols for accurate volume measurements.