TY - JOUR
T1 - Value of CT spectral imaging in the differential diagnosis of thymoma and mediastinal lymphoma
AU - Xie, Yijing
AU - Zhang, Shipeng
AU - Liu, Jianli
AU - Liang, Xiaohong
AU - Zhang, Xueling
AU - Zhang, Yuting
AU - Zhang, Zhuoli
AU - Zhou, Junlin
N1 - Funding Information:
This work was supported by Talent Innovation and Entrepreneurship Project of Lanzhou (No.2016-RC-58), and Natural Science Foundation Project of Gansu Province (No.17JR5RA253).
Publisher Copyright:
© 2019 The Authors. Published by the British Institute of Radiology under the terms of the Creative Commons Attribution-NonCommercial 4.0 Unported License
PY - 2019
Y1 - 2019
N2 - Objective: To investigate the imaging characteristics of thymoma and mediastinal lymphoma using spectral CT and evaluate whether the quantitative information can improve the differential diagnosis of these diseases. Methods: This retrospective study was approved by the institutional review board, and written informed consent was obtained from all patients. Overall, 39 patients with mediastinal tumors (24 thymomas and 15 mediastinal lymphomas) were examined with CT spectral imaging during the arterial phase (AP) and venous phase (VP). Iodine concentrations were derived from iodine-based material-decomposition CT images and normalized to the iodine concentration in the aorta. The difference in normalized iodine concentrations (NICs), HU curve slop(λHU), and the differences between AP and VP for CT values of lesions in 70 Kev were calculated. The two-sample t-test was performed to compare quantitative parameters, and non-quantitative parameters were compared with the Chi-square test (Fisher exact). Receiver operating characteristic (ROC) curves were generated to help establish threshold values for the parameters required for the significant differentiation of thymomas from mediastinal lymphomas. Two readers qualitatively assessed the lesion types according to the imaging features. The sensitivity and specificity of the qualitative and quantitative studies were compared. Results: NICs during the VP and λHU during the AP in patients with mediastinal lymphomas differed significantly from those in patients with thymomas. The mean NICs during the VP were 0.28 ± 0.08 mgml−1 (±standard deviation) vs 0.49 ± 0.15 mgml−1, respectively. The λHU during the AP was 0.69 ± 0.17 vs 1.26 ± 0.74, respectively. The NICs during the VP and λHU during the AP had high sensitivity and specificity in differentiating mediastinal lymphomas from thymomas. The tumor location, margin, necrosis, presence of swollen mediastinal lymph nodes, relationship with adjacent vessels, and enhancement pattern differed significantly between the groups (p < 0.05). The combination of NICs and λHU had higher sensitivity and specificity than did those of conventional qualitative CT image analysis during the combined phases. Conclusion: CT spectral imaging has promising potential for the diagnostic differentiation of mediastinal lymphomas and thymomas. The iodine content and λHU could be valuable parameters for differentiating thymomas and mediastinal lymphomas. Advances in knowledge: The iodine content and HU, provided by spectral CT, could be used as new parameters to distinguish mediastinal lymphomas from thymomas.
AB - Objective: To investigate the imaging characteristics of thymoma and mediastinal lymphoma using spectral CT and evaluate whether the quantitative information can improve the differential diagnosis of these diseases. Methods: This retrospective study was approved by the institutional review board, and written informed consent was obtained from all patients. Overall, 39 patients with mediastinal tumors (24 thymomas and 15 mediastinal lymphomas) were examined with CT spectral imaging during the arterial phase (AP) and venous phase (VP). Iodine concentrations were derived from iodine-based material-decomposition CT images and normalized to the iodine concentration in the aorta. The difference in normalized iodine concentrations (NICs), HU curve slop(λHU), and the differences between AP and VP for CT values of lesions in 70 Kev were calculated. The two-sample t-test was performed to compare quantitative parameters, and non-quantitative parameters were compared with the Chi-square test (Fisher exact). Receiver operating characteristic (ROC) curves were generated to help establish threshold values for the parameters required for the significant differentiation of thymomas from mediastinal lymphomas. Two readers qualitatively assessed the lesion types according to the imaging features. The sensitivity and specificity of the qualitative and quantitative studies were compared. Results: NICs during the VP and λHU during the AP in patients with mediastinal lymphomas differed significantly from those in patients with thymomas. The mean NICs during the VP were 0.28 ± 0.08 mgml−1 (±standard deviation) vs 0.49 ± 0.15 mgml−1, respectively. The λHU during the AP was 0.69 ± 0.17 vs 1.26 ± 0.74, respectively. The NICs during the VP and λHU during the AP had high sensitivity and specificity in differentiating mediastinal lymphomas from thymomas. The tumor location, margin, necrosis, presence of swollen mediastinal lymph nodes, relationship with adjacent vessels, and enhancement pattern differed significantly between the groups (p < 0.05). The combination of NICs and λHU had higher sensitivity and specificity than did those of conventional qualitative CT image analysis during the combined phases. Conclusion: CT spectral imaging has promising potential for the diagnostic differentiation of mediastinal lymphomas and thymomas. The iodine content and λHU could be valuable parameters for differentiating thymomas and mediastinal lymphomas. Advances in knowledge: The iodine content and HU, provided by spectral CT, could be used as new parameters to distinguish mediastinal lymphomas from thymomas.
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U2 - 10.1259/bjr.20180598
DO - 10.1259/bjr.20180598
M3 - Article
C2 - 30507309
AN - SCOPUS:85061997490
SN - 0007-1285
VL - 92
JO - British Journal of Radiology
JF - British Journal of Radiology
IS - 1095
M1 - 20180598
ER -