DWI of head and neck cancer the effect of b values on ADC measurements

Introduction: Diffusion weighted imaging (DWI) has recently been considered a potential tool for the investigation of head and neck cancer. This technique has been used both for the characterization of tumors and the monitoring of their treatment response after radiotherapy and chemotherapy. Application of this technique relies on the measurement of the apparent diffusion coefficient (ADC) which is calculated from the DWI dataset. However, there is no generally agreed DWI protocol, including no agreement on the magnitude and number of bvalues which should be used to obtain the ADC map. Whether differences in the magnitude and number of b-values have an effect on the ADC measurement is still unclear. The aim of this study was to examine the effect of b-values on ADC measurement of cancer in a group of patients with nasopharyngeal carcinoma (NPC).