Role of diffusion-weighted Echo-Planar MR imaging in differentiation of residual or recurrent head and neck tumors and posttreatment changes

Abstract

BACKGROUND AND PURPOSE: The purpose of this work was to evaluate whether diffusion-weighted MR imaging can be used in differentiating residual or recurrent head and neck tumors from postoperative or postradiation changes. MATERIALS AND METHODS: This study included 32 patients clinically suspected for recurrent head and neck tumor after surgery (n = 3), radiation therapy (n = 13), or both (n = 16). Diffusion-weighted MR imaging was done by using a single-shot spin-echo echo-planar sequence. The apparent diffusion coefficient (ADC) value of the suspected lesion was calculated and correlated with pathologic results. RESULTS: Adequate diffusion-weighted MR images and ADC maps were obtained in 30 patients (93.8%). The mean ADC value of residual or recurrent lesions (1.17 ± 0.33 × 10-3 mm2/s) was less than that of posttherapeutic changes (2.07 ± 0.25 × 10-3 mm 2/s), and the difference was statistically significant (P