TITLE:
Retrospective Study of Bone Mineral Density through Phantom-Less Quantitative CT
AUTHORS:
Hongmin Xu, Alexander Kui, Alice Barrington, Emad Allam, Jian-Feng Chen
KEYWORDS:
Quantitative CT (QCT), Bone Mineral Density (BMD), Thoracic BMD, Lumbar BMD, Phantom-Less
JOURNAL NAME:
Open Journal of Radiology,
Vol.15 No.1,
February
10,
2025
ABSTRACT: Background: Quantifying bone mineral density (BMD) is important to monitor and evaluate bone health status. When applied to chest and abdomen CT images, the BMD values of thoracic and lumbar spines can be determined. Objective: This study aims to analyze the distribution of lumbar BMD across different age groups and races, investigate the correlation between lumbar BMD and thoracic BMD, evaluate the feasibility of using chest CT scans for BMD assessment, and analyze numerical data to establish CT-based thresholds for diagnosing osteopenia and osteoporosis. Methodology: CT imaging data from 400 female subjects aged 20 - 80 years, acquired from 2010 to 2022, was studied retrospectively. We examined variations in lumbar BMD among females across different ages and races. The thoracic BMD values were measured relative to aortic blood and subcutaneous adipose tissue on chest CT images, while the lumbar BMD values were measured relative to psoas muscle and subcutaneous adipose tissue on abdominal CT images. Then, the correlation coefficient of BMD values between thoracic and lumbar was calculated. The receiver operating characteristic (ROC) of thoracic spine BMD values was studied with the lumbar spine BMD values considered the gold standard for osteoporosis diagnosis. Results: Thoracic BMD ranged from 60 - 350 mg/cm3, while lumbar BMD ranged from 60 - 350 mg/cm3 in most subjects. Between thoracic and lumbar BMD, a strong positive correlation (r = 0.95) was determined and the area under the ROC curve was 0.969. Lumbar BMD demonstrates age-related decline and has a strong positive correlation with thoracic BMD. Among the four major racial groups—White, Black, Hispanic, and Asian—Hispanics exhibited the highest lumbar BMD, while Whites showed the lowest. Conclusions: Lumbar BMD demonstrates age-related decline and strongly correlates with thoracic BMD. These findings support the use of CT as a valuable tool in screening for osteoporosis.