Atsuo Inoue1, Noriyuki Tomiyama1, Kiminori Fujimoto2, Junko Sadohara2, Itsuko Nakamichi3, Yasuhiko Tomita3, Katsuyuki Aozasa3, Mitsuko Tsubamoto1, Sachiko Murai1, Javzandulam Natsag1, Hiromitsu Sumikawa1, Naoki Mihara1, Osamu Honda1, Seiki Hamada1, Takeshi Johkoh4, Hironobu Nakamura1
1Department of Radiology, Osaka University Graduate School of Medicine, Osaka, Japan
2Department of Radiology, Kurume University School of Medicine, Kurume, Japan
3Department of Pathology, Osaka University Graduate School of Medicine, Osaka, Japan
4Department of Medical Physics, Osaka University Graduate School of Medicine, Osaka, Japan
Tóm tắt
The aim of this study was to determine magnetic resonance imaging (MRI) features of various subtypes of thymic epithelial tumors based on the World Health Organization classification. The study included 64 patients with histologically proven thymic epithelial tumors. Two observers evaluated the MRI findings in terms of tumor size, contour, lobulation, shape, homogeneity, the presence of intratumor high- and low-signal foci, enhancement degree and pattern, the presence of capsule and septum, and associated mediastinal lymphadenopathy and pleural effusion. Type A tumors were more likely to have a smooth contour, round shape, distinct capsule, and smaller size compared to any other type of thymic epithelial tumor. Thymic carcinomas demonstrated a higher prevalence of low-signal foci within the mass on T2-weighted images and mediastinal lymphadenopathy than any other types. The frequency of heterogeneous intensity on T2-weighted images increased from type A tumors to thymic carcinomas. The presence of a smooth contour, round shape, and capsule is highly suggestive of a type A tumor. Foci of low signal intensity in the mass on T2-weighted images and mediastinal lymphadenopathy are highly suggestive of thymic carcinomas.