Bone Density Measurement Based on Material Decomposition Images of Spectral CT / 中国医学影像学杂志

ABSTRACT

Purpose To explore the value of hydroxyapatite (HAP) in the measurement of bone mineral density (BMD) based on the quantitative material decomposition images of spectral CT on healthy adult females.Materials and Methods A total of 128 healthy females who underwent upper abdominal CT examination with spectral CT at the Second Hospital of Lanzhou University from September 2013 to February 2016 were enrolled as the research group.Those patients with trauma,surgery,tumor or other diseases affecting BMD were excluded.The patients (ages ranged from 18 to 87 years) were divided into 6 groups according to their ages＜30 years (n=23),30-39 years (n=20),40-49 years (n=22),50-59 years (n=24),60-69 years (n=19) and ≥ 70 years (n=20).The HAP and calcium concentration at central part of L2 centrum of spongy bone were measured.Meanwhile,119 healthy females who underwent dual energy X-ray absorption (DEXA) examination were selected as the controls and also divided into groups according to the same criteria as the research group.The BMD of the controls was also measured at L2 centrum and showed as areal density (g/cm2).The measurements of the research group were analyzed.The correlation analysis was done between hydroxyapatite,calcium concentration and age.The correlations between hydroxyapatite,calcium concentration and BMD obtained by DEXA were also analyzed.Results There were significant differences in the HAP and calcium concentration among different age groups (P＜0.05).The results of spectral CT and the DEXA showed correlations.Both HAP and calcium concentration showed positive relationship with BMD obtained by DEXA (r=0.874 and 0.796,respectively,both P＜0.05).The HAP and calcium concentration showed positive relationship with age in the groups (ages ranged from 18-39 years) (r=0.538 and 0.416,P＜0.05) and negative relationship with age in the groups (ages over 40 years) (r=-0.629 and-0.562,P＜0.05).Conclusion Material decomposition images of spectral CT can reflect bone changes,and HAP is a new base material for BMD measurement.