Diagnostic ability of spectral CT-based vertebral hydroxyapatite concentration for bone mineral density assessment in patients with liver cirrhosis: evaluating in unenhanced, arterial, and portal venous phase after intravenous contrast administration

Objectives To access the impact of intravenous contrast on the diagnostic efficacy of abdominal spectral CT-based vertebral hydroxyapatite (HAP) concentration measurement for bone mineral density (BMD) assessment in menopausal women, women undergoing menopausal transition, and men older than 50 years with liver cirrhosis. Methods 172 patients (mean age, 63.78 ± 7.20 years; range, 51–82 years) with liver cirrhosis enrolled in the study. These individuals underwent comprehensive abdominal spectral abdominal spectral CT scans, which included both unenhanced and contrast-enhanced arterial phase (AP) and portal venous phase (VP). Vertebral HAP concentration was quantified in the medullary compartment of vertebral body (L1–L3) using HAP-based material decomposition images. The receiver operating characteristic (ROC) curves were adapted to investigate the diagnostic efficacy of using unenhanced, AP and VP HAP concentrations for evaluating BMD validated by T-scores on dual-energy x-ray absorptiometry. Results HAP values were significantly different among the three scan phases (all P < 0.05). By adjusting thresholds, high accuracies were obtained for detecting low bone mass (osteoporosis or osteopenia) with HAP measurements in all scan phases (all areas-under-ROC > 0.9). The data did not reveal a statistically significant disparity between the unenhanced and AP (P = 0.055) to detect low bone mass. The efficacies for detecting low bone mass had statistically significant reduction with HAP concentrations in VP (P = 0.012). Conclusions Vertebral HAP concentrations increased in AP and VP compared to unenhanced phase. Advances in knowledge Adjusting thresholds higher in contrast-enhanced phases may maintain high detection efficacies for low bone mass.