
Sameer J. Ahamed Sr. , Mahesh Shekoba , Ankith N V , Sabah Sulaiman , Aneesh MK , Monish Nachu , Srinivasalu Santhanagopal , Mallikarjuna B. Swamy 1. Department of Spine Surgery, St. Johnfs Medical College Hospital, Bangalore, IND 2. Department of Spine Surgery, St. Johnfs Medical College Hospital, Bangaluru,Karnataka, IND 3. Department of Spine Surgery, St. Johnfs Medical College Hospital, Bengaluru, IND Corresponding author: Ankith N V, ankithnv1989@gmail.com Abstract Study Design: Retrospective study. Purpose: To evaluate the diagnostic potential of Hounsfield Unit (HU) values from computed tomography (CT) and Vertebral Bone Quality (VBQ) scores from magnetic resonance imaging (MRI) as non-invasive alternatives to dual-energy X-ray absorptiometry (DEXA) for osteoporosis detection. Overview of Literature: DEXA is the gold standard for assessing bone mineral density (BMD), but it has limitations including radiation exposure and interference from degenerative changes. HU and VBQ are promising, radiation-free imaging techniques assessing different aspects of bone health: HU reflects trabecular bone density, while VBQ quantifies marrow fat content, inversely related to bone strength. Methods: A retrospective analysis of 112 adults who underwent lumbar spine DEXA, CT, and MRI within 30 days. HU was measured at the L3 vertebral body on CT, and VBQ scores were derived from MRI by comparing vertebral signal intensities to cerebrospinal fluid. Correlations with DEXA T-scores and diagnostic performance metrics, including ROC analysis, were assessed. Results: HU values demonstrated a positive correlation with DEXA T-scores (r = 0.549, p < 0.001), with decreasing HU values as BMD worsened. VBQ scores showed weaker, non-significant correlation (r = -0.175, p = 0.064). HU exhibited higher diagnostic accuracy (AUC = 0.90) than VBQ (AUC = 0.75). Combination testing improved diagnostic performance: series testing (both HU . 110 and VBQ . 3.9) showed 50% sensitivity and 83% specificity, while parallel testing (either HU . 110 or VBQ . 3.9) demonstrated 86% sensitivity and 51% specificity. Conclusions: CT-derived HU and MRI-based VBQ scores are complementary biomarkers for osteoporosis assessment. HU offers strong diagnostic accuracy, while VBQ provides a radiation-free alternative. The combination of both methods enhances diagnostic performance, making them valuable for osteoporosis screening, especially when DEXA is unavailable. Categories: Radiology, Neurosurgery, Orthopedics Keywords: bone mineral density, ct, dexa, hounsfield units, mri, osteoporosis, vertebral bone quality Introduction Osteoporosis is a skeletal disorder marked by low bone mass and microarchitectural deterioration, increasing fracture risk [1-2].Early diagnosis is vital to prevent fragility fractures, especially in the elderly. Dual-energy X-ray Absorptiometry (DEXA) remains the gold standard for assessing bone mineral density (BMD) and guiding management with WHO-based T-scores categorizing patients as normal, osteopenic, or osteoporotic [3]. Despite its widespread use, DEXA has several important limitations. First, it provides only a twodimensional areal BMD measurement that lacks information about bone microarchitecture and quality [3-4]. Second, DEXA results may be skewed by degenerative changes, aortic calcifications, and vertebral fractures, particularly in elderly [5]. Additionally, accessibility and patient compliance with DEXA screening remain 1 2 1 1 1 3 1 1
To evaluate the diagnostic potential of Hounsfield Unit (HU) values from computed tomography (CT) and
Vertebral Bone Quality (VBQ) scores from magnetic resonance imaging (MRI) as non-invasive alternatives to
dual-energy X-ray absorptiometry (DEXA) for osteoporosis detection.
Overview of Literature:
DEXA is the gold standard for assessing bone mineral density (BMD), but it has limitations including
radiation exposure and interference from degenerative changes. HU and VBQ are promising, radiation-free
imaging techniques assessing different aspects of bone health: HU reflects trabecular bone density, while
VBQ quantifies marrow fat content, inversely related to bone strength.
Methods:
A retrospective analysis of 112 adults who underwent lumbar spine DEXA, CT, and MRI within 30 days. HU
was measured at the L3 vertebral body on CT, and VBQ scores were derived from MRI by comparing vertebral
signal intensities to cerebrospinal fluid. Correlations with DEXA T-scores and diagnostic performance
metrics, including ROC analysis, were assessed.
Results:
HU values demonstrated a positive correlation with DEXA T-scores (r = 0.549, p < 0.001), with decreasing HU
values as BMD worsened. VBQ scores showed weaker, non-significant correlation (r = -0.175, p = 0.064). HU
exhibited higher diagnostic accuracy (AUC = 0.90) than VBQ (AUC = 0.75). Combination testing improved
diagnostic performance: series testing (both HU . 110 and VBQ . 3.9) showed 50% sensitivity and 83%
specificity, while parallel testing (either HU . 110 or VBQ . 3.9) demonstrated 86% sensitivity and 51%
specificity.
Conclusions:
CT-derived HU and MRI-based VBQ scores are complementary biomarkers for osteoporosis assessment. HU
offers strong diagnostic accuracy, while VBQ provides a radiation-free alternative. The combination of both
methods enhances diagnostic performance, making them valuable for osteoporosis screening, especially
when DEXA is unavailable