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Objective: To observe the energy spectral CT manifestations of focal organizing pneumonia (FOP) and peripheral lung cancer (PLC). Methods: Data of 40 patients with FOP (FOP group) and 60 patients with PLC (PLC group) confirmed by pathology who underwent chest dual-phase energy spectral CT were retrospectively analyzed. CT40~100 keV values on single energy images, iodine concentration, water concentration and effective atomic number at arterial and venous phase of lesions were measured and recorded, respectively. The corresponding energy spectral curve was drawn, and the slope of the curve was calculated. The quantitative parameters were compared between 2 groups. Results: There was no statistically differences of patients' age, gender, clinical symptoms nor lesions' size or location between 2 groups (all P>0.05). CT40 keV, CT50 keV, CT60 keV and CT 70 keV values, λ70 keV, iodine concentration, effective atomic number at arterial phase in PLC group were all higher than those in FOP group (t=3.46, 3.08, 3.08, 2.03, 2.32, 2.69, 2.73, all P0.05). Conclusion: Energy spectral CT findings of FOP and PLC had certain difference, providing references for differential diagnosis of FOP and PLC.
RESUMO
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.