Introduction Emerging evidence shows that diffusion-weighted magnetic resonance imaging (DW MRI) and fluorine 18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) might be useful in predicting histological type and malignancy of lung cancer, and even in specifically detecting the types of gene mutation. Objective We assessed whether DW MRI is equivalent to PET/CT in lung cancer diagnosis and evaluation. Methods The institutional review board approved this study, and written informed consent was obtained from all patients. DW MRI and FDG PET/CT were performed before therapy in 15 lung cancer patients diagnosed by pathological examination. Apparent diffusion coefficient (ADC), ratio of ADC (rADC = ADC in tumor/ADC in spinal cord) and maximal standardized uptake value (SUVmax) were assessed. Results ADC, rADC and SUVmax did not reveal significant differences among different types of lung cancer. Sensitivity, specificity and accuracy of ADC, rADC and SUVmax proved to be not significantly different in the detection of adenocarcinoma and squamous cell carcinoma. Difference in the abilities of the sensitivity, specificity and accuracy of ADC, rADC and SUVmax to detect adenocarcinoma and squamous cell carcinoma proved to be insignificant. Although Ki-67 score did not show correlation with ADC, rADC and SUVmax, significant positive correlation was found between ADC and rADC, and ADC and SUVmax. Conclusions Both DW MRI and FDG PET/CT had similar limited diagnostic capability of predicting different histological types and malignancy of lung cancer. This study may help provide a novel insight into diagnostic and therapeutic strategies of lung cancer based on DW MRI.
