This study aims to evaluate the diagnostic efficacy and differences between 18F-FDG PET/CT and MR STIR sequences combined with EBUS-TBNA, 18F-FDG PET/CT combined with EBUS-TBNA, and MR STIR sequences combined with EBUS-TBNA - three types of multimodal imaging for assessing NSCLC N-stage, in order to select the best assessment protocol to guide treatment decisions and prognostic assessments.

Inclusion Criteria:

• Biopsy pathologically confirmed NSCLC, or clinically highly suspicious NSCLC (assessed as highly suspicious by the MDT team of this study);
• N1, N2, or N3 confined to the mediastinum and hilum, as assessed by imaging;
• Proposed systematic lymph node dissection without any treatment;
• Appropriate laboratory tests (serum tumor markers);
• All examination intervals ≤ 4 weeks;
• KPS score ≥ 50 (ECOG/WHO equivalent);
• Aged > 18 years; 8. Patients can fully understand and voluntarily participate in this trial and sign the informed consent; the examination can be completed independently.

Exclusion Criteria:

• Contraindication to EBUS-TBNA operation;
• Presence or history of other malignancies within 10 years;
• Inability to understand the examination procedure or to cooperate.