Combinations of two imaging parameters to improve bone mineral density (BMD) assessment in patients with lumbar degenerative diseases

(2023) 24:747 Li et al. BMC Musculoskeletal Disorders https://doi.org/10.1186/s12891-023-06888-8 BMC Musculoskeletal Disorders Open Access RESEARCH Combinations of two imaging parameters to improve bone mineral density (BMD) assessment in patients with lumbar degenerative diseases Wenshuai Li1,2†, Houze Zhu1,2†, Hongsen Tian1,2, Tong Tong1,2, Zijian Hua1,2, Xuan Zhao1,2, Yong Shen1,2 and Linfeng Wang1,2* Abstract Purpose To explore whether combining the Hounsfield unit (HU) values and vertebral bone quality (VBQ) scores can improve the BMD assessment in patients with lumbar degenerative diseases. Methods The HU values were measured by CT image, and VBQ scores were calculated by lumbar MRI image. The correlations of the opportunistic imaging parameters to the lowest T-scores were analyzed. Receiver-operating characteristic curve (ROC) analysis was used to evaluate the accuracy in detecting osteoporosis. Finally, the specificity and sensitivity of different combined methods of the HU values and VBQ scores in the diagnosis of osteoporosis were compared. Results Patients with osteoporosis had the lowest HU values and the highest VBQ scores. The correlation coefficients between the VBQ scores and the T-scores were smaller than HU values (L1 HU value: 0.702; average HU value:0.700; L1 VBQ score: -0.413; VBQ score: -0.386). The areas under the curve (AUCs) of the HU values were greater than those of the VBQ scores, and the AUCs of the L1 VBQ score were similar to the VBQ score (L1 HU value: 0.850; average HU value:0.857; L1 VBQ score: 0.704; VBQ score: 0.673). When combining the two imaging parameters in series, the specificity of the detection of osteoporosis was improved (L1 HU value and L1 VBQ score: 87.3%; Average HU value and VBQ score: 85.9%). When combining the two imaging parameters in parallel, the sensitivity of the detection of osteoporosis was improved (L1 HU value or L1 VBQ score: 88.1%; Average HU value or VBQ score: 91.5%). Conclusions Combinations of the HU values and VBQ scores could improve the diagnostic performance of osteoporosis. In addition, considering the same diagnostic performance but easier measurement, parameters at the singlesegment level were recommended to assist in the diagnosis of osteoporosis. Keywords Osteoporosis, Hounsfield units, Vertebral bone quality, Lumbar degenerative disease † Wenshuai Li and Houze Zhu contributed equally to this work. *Correspondence: Linfeng Wang Full list of author information is available at the end of the article © The Author(s) 2023. 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The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data. Li et al. BMC Musculoskeletal Disorders (2023) 24:747 Introduction Osteoporosis is defined as low bone mass and microarchitectural deterioration of bone tissue with consequent increases in bone fragility and susceptibility to fracture [1]. As the population ages, osteoporosis has become a common disease. Especially in patients requiring spinal surgery, bone mineral density (BMD) assessment is critical. Osteoporosis is one of the important risk factors for complications such as fixation failure, screw loosening, and pseudarthrosis after spinal surgery [2–4]. Dual energy x-ray absorptiometry (DXA) is presently used as the gold standard method for assessing BMD [5]. WHO diagnostic criteria for osteoporosis are often used clinically [4]: osteoporosis (the lowest T-score ≤ − 2.5), osteopenia (− 2.5 < the lowest T-score < − 1), and normal BMD (the lowest T-score ≥ − 1). However, DXA sometimes may not reflect the vertebral cancellous BMD well because of degenerative arthritis, osteophyte formation, and spinal sclerosis [6–8]. To more accurately measure the vertebral cancellous BMD, several tools that assist DXA have been widely studied [9–12]. The Hounsfield unit (HU) value obtained by computed tomography (CT) scanning was considered a useful technique for the assessment of lumbar BMD, and the corresponding threshold has been established [9–11]. Schreiber et al. [13] initially found that the HU value was significantly correlated with BMD and T-score, and also significantly correlated with compressive strength. Subsequently, Pickhardt et al. [14] used abdominal CT to perform opportunistic screening for osteoporosis, further improved a study involving 1867 samples, and established corresponding thresholds. When the HU value is close to 110, it is considered that the screening of osteoporosis has good specificity. After that, a large number of studies proved the correlation between lumbar HU value and BMD and also obtained similar conclusions. In addition, some studies have also found that the HU value can predict osteoporosis-related complications [15, 16]. Another novel technique for assessing bone quality is the vertebral bone quality (VBQ) score, which uses non-contrast, T1-weighted lumbar spine MRI and has a good diagnostic ability of osteoporosis [12, 17]. When the T-score was used as a criterion, the VBQ score was about 80% accurate in determining osteoporosis and the threshold of VBQ score is close to 3.0 [18]. Subsequently, a study has shown that the VBQ score is an independent predictor of fragility fractures [19]. More recently, the VBQ score is an effective indicator of bone quality in patients with osteoporotic compression fractures [20]. In addition, the VBQ score has been shown to have moderate to excellent intra-rater reliability (ICC:0.667–0.957) and good inter-rater reliability (ICC: 0.818), which makes the method easy to generalize [21]. Page 2 of 10 A common benefit of the HU value and VBQ score is that they can be used to measure the region of interest (ROI), so the region that affects the measurement of cancellous bone in the vertebral body can be avoided. Because lumbar CT and MRI are often routine examinations for patients undergoing lumbar surgery, another common benefit of the HU value and VBQ score is the use of opportunistic imaging to provide meaningful data on bone mass that avoids additional financial (...truncated)