GIÁ TRỊ CỦA CỘNG HƯỞNG TỪ KHUẾCH TÁN VÀ ĐỘNG HỌC BẮT THUỐC TRONG CHẨN ĐOÁN U BIỂU MÔ TUYẾN ỨC

Abstract

Introduction: Thymic epithelial tumor (TET) is the most common neoplasm of the adult’s anterior mediastinum. Chest magnetic resonance imaging (MRI) has been increasingly introduced into clinical practice thanks to its excellent tissue characterization and evidence of lowering the number of unnecessary interventions. Diffusion-weighted (DW) imaging provides information on the cellularity of tumors, and dynamic contrast-enhanced (DCE) technique helps to assess tumor perfusion. The present study was conducted with the aim of depicting the DW and DCE magnetic resonance (MR) findings of TETs. Methods: This is a retrospective study including 56 TET patients that underwent chest MR scanning from September 2018 to July 2022. The pathologically-proven tumors were classified into three groups according to the simplified WHO classification: low-risk thymoma (LRT), high-risk thymoma (HRT), and non-thymoma (NT). The apparent diffusion coefficient (ADC) value, time-intensity curve (TIC) pattern, and time to peak enhancement (TTP) of these tumors were recorded and compared between the three groups. Results: ADC values decreased with increasing malignancy. The ADC values ​​were highest in LRT (median: 1.04), lower in HRT (median: 0.93), and lowest in NT (median: 0.69) (unit: x 10^-3 mm²/sec). Thymoma achieved peak enhancement sooner than NT, of which the median TTP was 105 and 180 sec, consecutively. LRT (median TTP: 60 sec) reached peak enhancement earlier than HRT (median TTP: 120 sec) or NT (median TTP: 180 sec). The washout TIC was the predominant pattern in LRT (71.4%). In the HRT group and the NT group, the most common TIC pattern was the plateau (52.6% and 56.2%, respectively).Conclusion: DW and DCE-MRI are useful advanced MR tools to characterize TETs.