Figure 4

Image example comparing bone mineral density (BMD) measurements in terms of hydroxylapatit concentrations with synchronous and asynchronous calibration. (A) BMD measurement in the first vertebra of the lumbar spine (L1) of an 84-year-old female, showing a BMD of 102.2 mg/ml. BMD is calculated based on CT numbers of a non-contrast CT scan using the asynchronous reference values determined in this study. (B) Automated segmentation of L1 in the same 84-year-old female scanned with the reference phantom using syngo Osteo CT (Siemens Healthineers). Reported BMD of 96.2 mg/ml for L1 using synchronous calibration.