Opportunistic screening for osteoporosis using routine clinical care computed tomography brain studies

Dee Zhen Lim; Milo Macbain; Marcus Kok; Ghanda Wiggins; Hussein Abbouchie; Sze Ting Lee; Eddie Lau; Ruth P Lim; Cherie Chiang; Numan Kutaiba

doi:10.1007/s00256-024-04703-6

Opportunistic screening for osteoporosis using routine clinical care computed tomography brain studies

Skeletal Radiol. 2024 May 16. doi: 10.1007/s00256-024-04703-6. Online ahead of print.

Authors

Dee Zhen Lim¹, Milo Macbain², Marcus Kok³, Ghanda Wiggins², Hussein Abbouchie², Sze Ting Lee^{4

5}, Eddie Lau^{2

4

5}, Ruth P Lim^{2

5}, Cherie Chiang^{5

6}, Numan Kutaiba^{2

3

5}

Affiliations

¹ Department of Radiology, Austin Health, 145 Studley Road, Heidelberg, VIC, 3084, Australia. deezhen.lim2@austin.org.au.
² Department of Radiology, Austin Health, 145 Studley Road, Heidelberg, VIC, 3084, Australia.
³ Department of Radiology, Eastern Health, 8 Arnold Street, Box Hill, VIC, 3128, Australia.
⁴ Department of Molecular Imaging and Therapy, Austin Health, 145 Studley Road, Heidelberg, VIC, 3084, Australia.
⁵ University of Melbourne, Grattan Street, Parkville, VIC, 3010, Australia.
⁶ Department of Endocrinology, Austin Health, 145 Studley Road, Heidelberg, VIC, 3084, Australia.

PMID: 38755335
DOI: 10.1007/s00256-024-04703-6

Abstract

Objective: Osteoporosis and falls are both prevalent in the elderly, and CT brain (CTB) is frequently performed post head-strike. We aim to validate the relationship between frontal bone density (Hounsfield unit) from routine CTB and bone mineral density from dual-energy X-ray absorptiometry (DEXA) scan for opportunistic osteoporosis screening.

Materials and methods: Patients who had a non-contrast CTB followed by a DEXA scan in the subsequent year were included in this multi-center retrospective study. The relationship between frontal bone density on CT and femoral neck T-score on DEXA was examined using ANOVA, Pearson's correlation, and receiver operating curve (ROC) analysis. Sensitivity, specificity, negative and positive predictive values, and area under the curve (AUC) were calculated.

Results: Three hundred twenty-six patients (205 females and 121 males) were analyzed. ANOVA analysis showed that frontal bone density was lower in patients with DEXA-defined osteoporosis (p < 0.001), while Pearson's correlation analysis demonstrated a fair correlation with femoral neck T-score (r = 0.3, p < 0.001). On subgroup analysis, these were true in females but not in males. On ROC analysis, frontal bone density weakly predicted osteoporosis (AUC 0.6, 95% CI 0.5-0.7) with no optimal threshold identified. HU < 610 was highly specific (87.5%) but poorly sensitive (18.9%). HU > 1200 in females had a strong negative predictive value for osteoporosis (92.6%, 95% CI 87.1-98.1%).

Conclusion: Frontal bone density from routine CTB is significantly different between females with and without osteoporosis, but not between males. However, frontal bone density was a weak predictor for DEXA-defined osteoporosis. Further research is required to determine the role of CTB in opportunistic osteoporosis screening.

Keywords: Computed tomography; Osteoporosis screening; Skull density.