Dual-Energy CT in the Assessment of Mediastinal Lymph Nodes: Comparative Study of Virtual Non-Contrast and True Non-Contrast Images.
10.3348/kjr.2013.14.3.532
- Author:
Seon Young YOO
1
;
Yookyung KIM
;
Hyun Hae CHO
;
Mi Joo CHOI
;
Sung Shine SHIM
;
Jeong Kyong LEE
;
Seung Yon BAEK
Author Information
1. Department of Radiology, School of Medicine, Ewha Womans University, Seoul 158-710, Korea.
- Publication Type:Original Article ; Comparative Study ; Evaluation Studies
- Keywords:
Dual-energy CT;
Chest;
Lymph nodes;
Virtual non-contrast;
Iodine subtraction
- MeSH:
Adult;
Aged;
Aged, 80 and over;
Calcinosis/*radiography;
Contrast Media/diagnostic use;
Female;
Humans;
Image Processing, Computer-Assisted;
Lymph Nodes/*radiography;
Male;
Mediastinum/*radiography;
Middle Aged;
Reproducibility of Results;
Sensitivity and Specificity;
Tomography, X-Ray Computed/*methods
- From:Korean Journal of Radiology
2013;14(3):532-539
- CountryRepublic of Korea
- Language:English
-
Abstract:
OBJECTIVE: To evaluate the reliability of virtual non-contrast (VNC) images reconstructed from contrast-enhanced, dual-energy scans compared with true non-contrast (TNC) images in the assessment of high CT attenuation or calcification of mediastinal lymph nodes. MATERIALS AND METHODS: A total of 112 mediastinal nodes from 45 patients who underwent non-contrast and dual-energy contrast-enhanced scans were analyzed. Node attenuation in TNC and VNC images was compared both objectively, using computed tomography (CT) attenuation, and subjectively, via visual scoring (0, attenuation < or = the aorta; 1, > the aorta; 2, calcification). The relationship among attenuation difference between TNC and VNC images, CT attenuation in TNC images, and net contrast enhancement (NCE) was analyzed. RESULTS: CT attenuation in TNC and VNC images showed moderate agreement (intraclass correlation coefficient, 0.612). The mean absolute difference was 7.8 +/- 7.6 Hounsfield unit (HU) (range, 0-36 HU), and the absolute difference was equal to or less than 10 HU in 65.2% of cases (73/112). Visual scores in TNC and VNC images showed fair agreement (kappa value, 0.335). Five of 16 nodes (31.3%) which showed score 1 (n = 15) or 2 (n = 1) in TNC images demonstrated score 1 in VNC images. The TNC-VNC attenuation difference showed a moderate positive correlation with CT attenuation in TNC images (partial correlation coefficient [PCC] adjusted by NCE: 0.455) and a weak negative correlation with NCE (PCC adjusted by CT attenuation in TNC: -0.245). CONCLUSION: VNC images may be useful in the evaluation of mediastinal lymph nodes by providing additional information of high CT attenuation of nodes, although it is underestimated compared with TNC images.
