双能CT检测肺内孤立性结节钙化的价值

Evaluation of dualenergy computed tomography in detection of calcification in solitary pulmonary nodule

目的探讨用双能ＣＴ检测肺内孤立性结节（ＳＰＮ）钙质存在的价值，建立一种判断ＳＰＮ良、恶性的新标准。方法用双能（８０、１４０ｋＶｐ）ＣＴ扫描水模、体模、正常人体、ＳＰＮ，分析其ＣＴ值变化，计算ＳＰＮ钙盐含量，再用设定密度范围所占区域的面罩样（ｄｅｎｓｉｔｙｍａｓｋ）后处理显示钙盐形态、分布，判断ＳＰＮ的良、恶性。结果水模、体模、正常人体及ＳＰＮ中含有高原子序数物质时，低能较高能时ＣＴ值升高，且在ｄｅｎｓｉｔｙｍａｓｋ后处理下显示出钙盐的分布及形态，用此方法诊断ＳＰＮ良、恶性的敏感性为８０％，特异性为８０％，χ２＝５，Ｐ＜０．００５。结论用此方法既能检测出ＳＰＮ内的钙化，又能显示出钙化形态和分布，对判断ＳＰＮ的良。

Objective To investigate a new method of detecting calcification in solitary pulmonary nodule (SPN) and to build a new standard of distinguishing benign from malignant SPN. Methods Dualenergy CT(140 kVp 80 kVp)was performed for water phantom,body phantom, normal volunteers and patients with SPN. The CT number changes were compared and their calcification contents were calculated. The shape and distribution of calcification were displayed by density mask processing and finally diagnosis of benign or malignant SPN was made. Results On low energy CT scan the CT number increased as compared with high energy scan for tissue with high atomic number. The SPN containing calcification also demonstrated increased CT value on low energy scan (sensitivity 80% and specifith 80%;P<0.005). Conclusions Dualenergy CT can demonstrate the calcifications in SPN as well as their appearance and distribution thereby it is a valuable imaging technique for detecting and diagnosing benign or malignant SPN.