The role of diffusion-weighted imaging and ADC value in head and neck lesions

Abstract

Aim:  To evaluate the contrast enhanced magnetic resonance imaging (MRI), diffusion weighted MRI findings of head and neck lesions in combination with histopathological diagnosis.

Method: Forty-two patients referred to our university, department of Radiology between July 2008 and June 2011 with a prediagnosis of head-neck lesion. Patients whom underwent contrast enhanced MRI, diffusion weighted MRI, and incisional or excisional biopsy, were included in the study. Patients, whose MRI examinations were suboptimal due to any artefacts, were excluded. After determination of MRI parameters, such as signal intensity, enhancement pattern, apparent diffusion coefficient (ADC) value, and contrast enhanced MRI and diffusion weighted MRI examinations were evaluated by a radiologist who had ten years of experience. Histopathological evaluation was made by a pathologist who had no information about patients’ MRI findings.

Results: The mean ADC value of benign and malignant lesions were 0.128x10-3±0.053 mm²/sn and 0.100x10-3±0.026mm²/sn respectively. ADC value was found to be significantly higher in benign lesions compared to malignant ones (p=0.032). Conventional MRI criteria such as signal intensity, internal structure, presence of cystic space and enhancement were found to be insignificant in the differentiation of benign and malignant lesions.

Conclusion: Conventional MRI sequences are important in the diagnosis of head and neck lesions but not sufficient due to the overlapping findings. Diffusion weighted MRI, applied in addition to conventional MRI examination, is an efficient technique and has additional diagnostic value in determining nature of head and neck lesions in the preoperative period.