BES TEST™ accuracy evaluation by means of 3D-printed phantoms

The BES TEST (TM) (Bone Elastic Structure Test), is a recently developed software medical device that detects pathological changes of bone trabecular architecture by measuring its elastic characteristics, known to be directly related to its resistance. The results are expressed by the Bone Structure Index (BSI) or by its T-score, that is the number of standard deviations from the healthy population average. Purpose: Evaluate the precision of BES TEST (TM) under reproducibility conditions, defined as repeated measurements on the same or similar objects which include different locations, operators, and measuring systems. Methods: A total of 5 I replicate measurements were performed by four different operators on five different phantoms. Each phantom was 3D printed using Stereolithography (SLA) and Fused Deposition Modeling (FDM) and has a unique internal structure that mimics trabecular bone. ISO 5725 guidelines were followed for the interpretation of results. Results: The 3D-printed phantoms performed like real bones when analyzed with BES TEST (TM). The reproducibility 95% Confidence Interval expressed in BSI is CIR = +/- 11.1, which corresponds in T-score to CIR,Tscore = +/- 0.49. The Least Significant Change in BSI is LSCR = +/- 7.9, which corresponds to LSCR,Tscore = +/- 0.35. Conclusion: The reproducibility of BES TEST (TM) within the admissible range is not inferior to that of gold standard tests for osteoporosis. 3D printing proved a valuable tool to perform reliable replicate measurements without having patients undergo unnecessary tests.