Utility of diffusion-weighted imaging with background signal suppression in metastatic cervical lymph nodes

Abstract

Objective To prospectively evaluate the value of diffusion-weighted imaging with background signal suppression (DWIBS) in the detection and diagnoses of metastatic cervical lymph nodes. Methods Twenty patients with head and neck squamous cell carcinomas underwent conventional MRI and DWIBS. The ADC values were measured and compared between metastatic and benign lymph nodes. The abilities of DWIBS and conventional MRI in the evaluation of metastatic cervical lymph nodes were compared. Results Conventional MRI demonstrated 101 lymph nodes, in which 58 were diagnosed as metastatic nodes. When MRI criteria were used for discrimination between metastatic and benign nodes, the obtained sensitivity, specificity, accuracy, positive and negative predictive value were 78% (47/60), 81%(44/54), 80% (91/114), 82% (47/57) and 77% (44/57), respectively. The mean ADC values of metastatic nodes (n =60) and benign nodes (n =54) were (0.945 ±0.122) × 10-3 mm2/s and (1. 210 ±0. 151 ) × 10-3 mm2/s ( t = - 10. 354 ,P ＜0. 01 ). When an ADC value of 1. 090 × 10 -3 mm2/s was used as the threshold for discrimination between metastatic and benign nodes, the obtained sensitivity, specificity,accuracy, positive and negative predictive value were 88% (53/60), 80% (43/54), 84% (96/114), 83%(53/64) and 86% (43/50), respectively. Conclusion DWIBS is helpful in diagnosing metastatic cervical lymph nodes of head and neck squamous cell carcinoma, and is superior to conventional MRI in their detection. Key words: Lymph nodes; Head and neck neoplasms; Diffusion magnetic resonance imaging