Design and Validation of Synchronous QCT Calibration Phantom: Practical Methodology

Abstract

Introduction: Quantitative computed tomography (QCT) can supplement dual x-ray absorptiometry by enabling geometric and compartmental bone assessments. Whole-body spiral CT scanners are widely available and require a short scanning time of seconds, in contrast to peripheral QCT scanners, which require several minutes of scanning time. This study designed and evaluated the accuracy and precision of a homemade QCT calibration phantom using a whole-body spiral CT scanner. Materials and Methods: The QCT calibration phantom consisted of K 2 HPO 4 solutions as reference. The reference material with various concentrations of 0, 50, 100, 200, 400, 1000, and 1200 mg/cc of K 2 HPO 4 in water were used. For designing the phantom, we used the ABAQUS software. Results: The phantoms were used for performance assessment of QCT method through measurement of accuracy and precision errors, which were generally less than 5.1 for different concentrations. The correlation between CT numbers and concentration were close to one (R 2 = 0.99). Discussion: Because whole-body spiral CT scanners allow central bone densitometry, evaluating the accuracy and precision for the easy to use calibration phantom may improve the QCT bone densitometry test. Conclusion: This study provides practical directions for applying a homemade calibration phantom for bone mineral density quantification in QCT technique. © 201