title: [Application of single-source dual-energy spectral CT in differentiating lymphoma and metastatic lymph nodes in the head and neck].
abstract: OBJECTIVE
  To investigate the feasibility of differentiation of lymphoma, metastatic lymph nodes of squamous cell carcinoma (SCC) and papillary thyroid carcinoma (PTC) in the head and neck by single-source dual-energy spectral CT.
  
  
  METHODS
  25 cases of non-Hodgkin lymphoma (NHL) with 236 lymph nodes, 3 cases of Hodgkin's lymphoma (HL) with 32 lymph nodes, 21 cases of SCC with 86 lymph nodes and 19 cases of PTC with 92 lymph nodes were evaluated by enhanced GSI. CT attenuation of lymph nodes in the monochromatic images at different keV levels and the iodine and water contents of these lymph nodes were measured. The slope of spectral curve was calculated using CT value at 40 keVand 90 keV. All results were analyzed with ANOVA and t test.
  
  
  RESULTS
  70 keV had the best single energy images. Normalized Hounsfield unit (NHU) of diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL), T lymphoblastic lymphoma (T-LBL), HL, PTC and SCC was 0.32 ± 0.10, 0.46 ± 0.08, 0.41 ± 0.11, 0.41 ± 0.11, 0.56 ± 0.15 and 0.34 ± 0.16, respectively. Normalized iodine concentration (NIC) of them was 0.20 ± 0.08, 0.32 ± 0.08, 0.25 ± 0.09, 0.30 ± 0.12, 0.49 ± 0.18 and 0.23 ± 0.18, respectively. The slope of spectral curve (k) of them was -1.92 ± 0.55, -2.45 ± 0.60, -1.82 ± 0.57, -2.57 ± 0.54, -5.44 ± 2.41 and -1.97 ± 0.81, respectively. Compared with the NHU, there was a statistically significant difference in each pair except DLBCL and SCC, and T-LBL and HL. Compared with the NIC, there was a statistically significant difference in each pair except DLBCL and SCC, FL and HL, T-LBL and SCC, and T-LBL and HL. Compared with the slope of spectral curve, there was statistically significant difference in each pair except DLBCL and T-LBL, DLBCL and SCC, FL and HL, and T-LBL and SCC.
  
  
  CONCLUSIONS
  Malignant lymph nodes of different types of diseases have certain different values of quantitative parameters in spectral CT imaging. By using CT attenuation, the shape and slope of spectral curve and the iodine content, single-source dual-energy CT may potentially provide a quantitative analysis tool for the diagnosis and differential diagnosis of lymph node alterations.
authors.affiliation: Department of Diagnostic Imaging, Cancer Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100021, China.
authors.forename: Xiaoyi
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Diagnostic Imaging, Cancer Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100021, China.
authors.forename: Yanfeng
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Department of Diagnostic Imaging, Cancer Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100021, China; Email: cjr.wuning@vip.163.com.
authors.forename: Ning
authors.initials: N
authors.lastname: Wu
authors.affiliation: Department of Diagnostic Imaging, Cancer Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100021, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Yang
authors.affiliation: Department of Diagnostic Imaging, Cancer Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100021, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Li
authors.forename: Zheng
authors.initials: Z
authors.lastname: Zhu
authors.forename: Dehong
authors.initials: D
authors.lastname: Luo
mesh_terms: D002277:Carcinoma / Q000000981:diagnostic imaging; D002291:Carcinoma, Papillary; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging; D003937:Diagnosis, Differential; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging*; D006689:Hodgkin Disease / Q000000981:diagnostic imaging; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging*; D008223:Lymphoma / Q000000981:diagnostic imaging*; D008224:Lymphoma, Follicular / Q000000981:diagnostic imaging; D016403:Lymphoma, Large B-Cell, Diffuse / Q000000981:diagnostic imaging; D008228:Lymphoma, Non-Hodgkin / Q000000981:diagnostic imaging; D009333:Neck; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed