DW MRI at 3.0 T versus FDG PET/CT for detection of malignant pulmonary tumors

Emerging evidence suggests that diffusion-weighted magnetic resonance imaging (DW MRI) could be useful for tumor detection with N and M staging of lung cancer in place of fluorine 18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT). DW MRI at 3.0 T and FDG PET/CT were performed before therapy in 113 patients with pulmonary nodules. Mean apparent diffusion coefficient (ADC), maximal standardized uptake value (SUVmax) and Ki-67 scores were assessed. Quantitatively, specificity and accuracy of ADC (91.7 and 92.9%, respectively) were significantly higher than those of SUVmax (66.7 and 77.9% respectively, p<0.05), although sensitivity was not significantly different between them (93.5 and 83.1%, p>0.05). Qualitatively, sensitivity, specificity and accuracy of DW MRI (96.1, 83.3 and 92.0%, respectively) were also not significantly different from that of FDG PET/CT (88.3, 83.3 and 86.7%, respectively, p>0.05). Significant negative correlation was found between Ki-67 score and ADC (r=-0.66, p<0.05), ADC and SUVmax (r=-0.37, p<0.05), but not between Ki-67 score and SUVmax (r=-0.11, p>0.05). In conclusion, quantitative and qualitative assessments for detection of malignant pulmonary tumors with DW MRI at 3.0 T are superior to those with FDG PET/CT. Furthermore, ADC could predict the malignancy of lung cancer. What's new? The standard noninvasive imaging tool in TNM staging of lung cancer is fluorine 18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT). Recent studies, however, have suggested that diffusion-weighted magnetic resonance imaging (DW MRI) may be as accurate as or better than FDG PET/CT for the detection and evaluation of lung cancer. Here, the diagnostic capability of DW MRI at 3.0 Tesla was found to be superior to that of FDG PET/CT, quantitatively and qualitatively, in the case of malignant pulmonary tumors. In addition, a possible prognostic role was identified for the technique's apparent diffusion coefficient.