Yang Qiushi, Wang Zeguo, Han Heli, Zhang Han, Yu Wanjiang
Department of Radiology, Qingdao Hospital, University of Health and Rehabilitation Sciences (Qingdao Municipal Hospital), Qingdao, China.
Quant Imaging Med Surg. 2024 Jun 1;14(6):4041-4053. doi: 10.21037/qims-23-1741. Epub 2024 May 24.
The technological innovation of fast kilovoltage (KV)-switching dual-energy computed tomography (DECT) has enabled the accurate measurement of vertebral bone density; however, it does not account for the effects of abdominal fat and ribs on the vertebral body. In our study, a European spine phantom (ESP) was used to establish an abdominal phantom for normal weight and obese people, and to explore the best scanning parameters for DECT to measure the bone mineral density (BMD) of the human lumbar spine.
Revolution CT was used to conduct energy spectrum scanning for each body mode. A total of 20 sets of energy spectrum scans was conducted and each set of conditions was scanned 10 times. The data conformed to a normal distribution, and the differences between the measured and actual values of ESP L1-3 vertebrae were compared using a one-sample -test, and quantitative data were described by . A P value <0.05 was considered statistically significant. Relative error (RE) and root mean square error (RMSE) of BMD measurements were calculated for different scanning conditions in normal and obese populations.
When simulating the upper abdominal condition (L1-2 level, fat area 140 cm, with rib influence) in a normal weight population, there was no statistical difference (P>0.05) in BMD measurements for each vertebra at 0.8 s/rotation (rot) with different tube currents, the smallest RE at 0.8 s/rot, 190 mA condition, and the smallest RMSE for L1 and 2 vertebral BMD measurements at 190 mA; when simulating the abdominal condition at the L4 level in a normal weight population (fat area of 240 cm, no rib influence), there were no statistical differences between the measurements at 0.8 s/rot, 190 and 275 mA conditions (P>0.05), and the RE and RMSE in the 190 mA condition was smaller than that in the 275 mA condition. Simulating the upper abdominal condition in the obese population (L1-2 level, fat area 340 cm, with rib influence), there were no statistical difference between the measurements in the 0.8 s/rot, 315 and 355 mA conditions (P>0.05), the RE and RMSE in the 315 mA condition was less than those in the 355 mA; simulated obese abdominal condition at the L4 level in the population (fat area 450 cm, no rib influence) resulted in 0.8 s/rot, no statistical difference in measurements between 315 mA (P>0.05), RE in 315 mA conditions were L1: 3.75%, L2: -1.06%, L3: 0.42%, and the RMSE under 315 mA condition were L1: 2.13, L2: 1.21, L3: 1.66.
When using Revolution CT to measure lumbar spine bone density, 0.8 s/rot at 190 mA may be the best scanning parameter for a normal weight population, and 0.8 s/rot at 315 mA may be the best scanning parameter for an obese population.
快速千伏（KV）切换双能计算机断层扫描（DECT）的技术创新使得能够准确测量椎体骨密度；然而，它没有考虑腹部脂肪和肋骨对椎体的影响。在我们的研究中，使用欧洲脊柱模型（ESP）为正常体重和肥胖人群建立腹部模型，并探索DECT测量人体腰椎骨密度（BMD）的最佳扫描参数。
使用Revolution CT对每种身体模型进行能谱扫描。共进行了20组能谱扫描，每组条件扫描10次。数据符合正态分布，使用单样本检验比较ESP L1 - 3椎体测量值与实际值之间的差异，定量数据用 描述。P值<0.05被认为具有统计学意义。计算正常和肥胖人群不同扫描条件下BMD测量的相对误差（RE）和均方根误差（RMSE）。
在正常体重人群中模拟上腹部情况（L1 - 2水平，脂肪面积140 cm，有肋骨影响）时，不同管电流下0.8秒/旋转（rot）时各椎体BMD测量无统计学差异（P>0.05），在0.8秒/rot，190 mA条件下RE最小，L1和2椎体BMD测量在190 mA时RMSE最小；在正常体重人群中模拟L4水平腹部情况（脂肪面积240 cm，无肋骨影响）时，0.8秒/rot，190和275 mA条件下测量无统计学差异（P>0.05），190 mA条件下的RE和RMSE小于275 mA条件下的。在肥胖人群中模拟上腹部情况（L1 - 2水平，脂肪面积340 cm，有肋骨影响）时，0.8秒/rot，315和355 mA条件下测量无统计学差异（P>0.05），315 mA条件下的RE和RMSE小于355 mA条件下的；在人群中模拟肥胖L4水平腹部情况（脂肪面积450 cm，无肋骨影响）时，0.8秒/rot，315 mA测量无统计学差异（P>0.05），315 mA条件下L1的RE为3.75%，L2为 - 1.06%，L3为0.42%，315 mA条件下L1的RMSE为2.13，L2为1.21，L3为1.66。
使用Revolution CT测量腰椎骨密度时，190 mA下0.8秒/rot可能是正常体重人群的最佳扫描参数，315 mA下0.8秒/rot可能是肥胖人群的最佳扫描参数。
