Opportunistic use of lumbar computed tomography and magnetic resonance imaging for osteoporosis screening

Compared with the healthy patients, patients with osteoporosis had a lower Hounsfield unit (HU) value and a higher vertebral bone quality (VBQ) score. Both the HU value and VBQ score can simply distinguish patients with osteoporosis (OP), with a cutoff value of HU value < 97.06 and VBQ score > 3.08.

The purpose of this study is to determine whether the opportunistic use of computed tomography (CT) or magnetic resonance imaging (MRI) is effective for identifying spine surgical patients with OP.

We retrospectively evaluated 109 lumbar spine surgery patients who received lumbar quantitative CT (QCT) and MRI. Using the area under the curve, the CT-based HU value and MRI-based VBQ score were calculated. Then, based on the QCT results, receiver operating characteristic (ROC) curves were constructed to determine the diagnostic performance of the HU value and VBQ score.

The HU value was significantly lower in the OP group, and the VBQ score was significantly higher in the OP group. Using the area under the curve, the diagnostic performance of the HU value and VBQ score for OP were 0.959 and 0.880, respectively. The diagnostic threshold values determined with optimal sensitivity and specificity were an HU value of 97.06 and a VBQ score of 3.08.

Opportunistic use of CT and MRI can simply distinguish patients with OP, which are expected to be potential alternatives to T-score for the osteoporosis screening.