Preoperative Osteoporosis Screening Using Thoracolumbar Computed Tomography with Asynchronous Calibration

<p>Introduction: Although bone health assessment prior to spine surgery is imperative, assessment of bone mineral density (BMD) with dual energy X-ray absorptiometry (DXA) is not easily available at all centers before spine surgery. Moreover, it has been recently reported that lumbar Computed Tomography (CT) -based Hounsfield Units (CTHU) correlate with BMD from DXA scans. If CTHU can be utilized for bone health assessment prior to spine surgery, it would be very useful to assess patients' bone health without added expense to the patient. Therefore, we investigated the usefulness of opportunistic assessment of bone health with CTHU.</p><p>Methods: Subjects comprised 138 patients who underwent a lumbar CT and DXA within a 6-month period. Three types of scanners were used for CT. CTHU values between the T12 and L4 vertebral levels were measured, calibrated by asynchronous phantom, compared to T-scores from DXA scans, and compared in patients with and without osteoporotic fractures. Furthermore, we also examined the threshold for DXA-defined osteoporosis (T-score ≤ −2.5) and the presence of osteoporotic fracture using receiver operating characteristic (ROC) curve analysis.</p><p>Results: CTHU values correlated with T-scores with DXA scan of both lumbar spine and hip. CTHU values were significantly lower in patients with osteoporotic fractures than in patients without osteoporotic fractures. Furthermore, the ROC analyses revealed that the thresholds for DXA-defined osteoporosis and the presence of osteoporotic fracture were 74.1 and 69.1, respectively.</p><p>Conclusions: CTHU values from three types of scanners correlates with T-scores with DXA scan of lumbar spine and hip and can be useful to screening of osteoporosis. The thresholds for DXA-defined osteoporosis and the presence of osteoporotic fracture were 74.1 and 69.1, respectively.</p>