Diffusion-weighted imaging with background body signal suppression (DWIBS) distinguishes benign lesions from malignant pulmonary solitary lesions.

This study aimed to determine applicable value of DWIBS in diagnosis of solitary pulmonary lesions. This study involved 32 solitary lung disease patients. T1W1, T2W1, T2WI-SPAIR were examined using MRI scanner and analyzed with View-forum 6.0 workstation. Imaging characteristics of pulmonary solitary lesions on DWIBS and ADC when b=300, 500 and 800 s/mm2 were observed. Signal-to-noise ratio (SNR), contrast-noise-ratio (CNR) and ADC value of lesions under different b-values were measured. Image quality in different b-values was compared by analyzing SNR and CNR. ADC values of benign and malignant lesions in different b-value groups were tested using t-test. ROC curve was used to evaluate diagnostic efficacy of ADC value, and obtain diagnostic threshold. The results indicated that SNR and CNR value of 300 and 500 s/mm2 group was significantly higher compared to 800 s/mm2 group (P<0.05). When b-value was assigned as 500 s/mm2, DWIBS demonstrated better and ideal images. ADC value of malignant lesions in different b-values was significantly lower compared to benign lesions (P<0.05), suggesting ADC value is a feasible approach for distinguishing benign from malignant lesions. AUC value of b=500 s/mm2 was significantly higher compared to b=300 and b=800 s/mm2 group (P<0.05). When b-value was assigned as 500 s/mm2, the best ADC threshold value was 1.435×10-3 mm2/s, with high sensitivity, specificity and accuracy of 80.0%, 83.3% and 84.4%, respectively. In conclusion, quantitative analysis of DWIBS examination and ADC value was helpful for qualitative diagnosis of pulmonary solitary lesions, and demonstrated potential to distinguish benign and malignant pulmonary solitary lesions.