Role of Apparent Diffusion Coefficient in Characterisation of Neck MassesA Cross-sectional Study

Abstract

Introduction: Neck masses are frequently encountered in clinical practice and differential diagnoses of a patient presenting with a neck mass is wide. Diffusion-Weighted Magnetic Resonance Imaging (DW-MRI) is an imaging technique based on molecular diffusion. It is a very helpful complementary technique in distinguishing neoplastic from non neoplastic tissue and has numerous applications in the evaluation of head and neck masses especially in head and neck lymphadenopathy. Aim: To evaluate the accuracy of Apparent Diffusion Coefficient (ADC) in differentiating benign and malignant neck masses. Materials and Methods: A single-centre cross-sectional study comprising of 50 patients of all age groups with clinical suspicion of neck swelling was conducted in Department of Radiodiagnosis at Sri Guru Ram Das Institute of Medical Sciences and Research, Amritsar, Punjab, India from March 2018 to February 2020. All patients included were subjected to general physical and detailed local examination. MRI was carried out on 1.5 Tesla Unit On Philips Intera Achieva using Sense Body Coil with b factor of 0 and 1000 s/mm² and ADC maps were generated and the results were compared with histopathological results and/or follow-up. Statistical assessment was carried out using Statistical Package for the Social Sciences (SPSS) version 24.0. Qualitative data were compared using the Chi-square test. Results: The most common cause of neck mass was lymph nodal masses (18%) with highest numbers of patients in age group 40-60 years (34%). When a cut-off ADC value of 1.1×10-3 s/ mm² was used, sensitivity of 95.23% and specificity of 89.65% were obtained for characterisation of malignant lesions which was statistically significant. There was a strong agreement (k value=0.838) in diagnosing the nature of lesion using ADC value on MRI with histopathological findings. Conclusion: Diffusion Weighted Imaging (DWI) and ADC values are new promising aspect of MRI and can help in differentiating the nature of the neck lesions. DWI can readily differentiate between benign and malignant lesions of neck with good efficacy and reproducibility.

Keywords

• hodgkins lymphoma
• ludwig’s angina
• mesenchymal tumour
• plunging ranula