Xiaosong Sun,1 Zhengchao Wei,1 Yiqiang Luo,2 Ming Wang1 

1Department of Thyroid-Head & Neck Surgery, Jilin Cancer Hospital, Changchun, People’s Republic of China; 2Department of Preventive Health Care, Jilin Cancer Hospital, Changchun, People’s Republic of China

Correspondence: Ming Wang, Email immc847@163.com

Background: Thyroid cancer exhibits the highest cervical lymph node metastasis rate (20– 50%) among head and neck malignancies, with occult metastasis occurring in 30– 80% of papillary carcinoma cases. However, conventional single-modality imaging faces certain challenges: MRI has limited sensitivity for detecting micro-metastases (< 2mm), while Doppler ultrasound may overlook metastases in isoechoic lymph nodes. Therefore, it is crucial to evaluate the diagnostic value of combining MRI and CDUS. This study aims to retrospectively analyze the diagnostic value of combining MRI and CDUS blood flow parameters in detecting cervical lymph node metastasis in thyroid cancer and to compare the diagnostic performance with MRI or CDUS alone.
Objective: To analyze the evaluation value of combining MRI and color Doppler ultrasound (CDUS) blood flow parameters in detecting cervical lymph node metastasis of thyroid cancer, particularly for occult metastases.
Methods: A retrospective analysis was conducted on 263 thyroid cancer patients (June 2022-June 2024). Diagnostic consistency between MRI, CDUS parameters (resistive index, pulsatility index, vascular patterns) and pathology were compared. Multimodal evaluation criteria were established: (1) MRI positive signs (lymph node diameter > 8mm, cystic change, enhancement heterogeneity) (2) CDUS thresholds (RI≥ 0.75, PI≥ 1.25 with chaotic vascularity).
Results: Among 263 patients, 98 had pathologically confirmed metastases. CDUS showed higher consistency with pathology (Kappa=0.783) than MRI (Kappa=0.645). Combined modality achieved 94.9% sensitivity vs 86.7% (CDUS) and 78.6% (MRI), with accuracy improving from 82.1%/75.3% to 89.4% (P< 0.05). Notably, 12/22 occult metastases (≤ 3mm) were only detected by combined approach.
Conclusion: The synergistic combination leverages MRI’s structural characterization and CDUS’s hemodynamic sensitivity, effectively overcoming single-modality limitations in detecting micro-metastases. This dual-assessment protocol addresses thyroid cancer’s propensity for early lymphatic spread, providing critical preoperative staging guidance.

Keywords: magnetic resonance imaging, ultrasound blood flow parameters, thyroid cancer, cervical lymph node metastasis, evaluation value