RESUMO
Objective To evaluate the value of diffusion weighted imaging (DWI)in distinguishing the solid solitary pulmonary nodule (SPN).Methods 42 patients with SPN (malignant in 25 and benign in 1 7)who were confirmed by operation,biopsy or follow up after treatment underwent routine chest T1 WI,T2 WI and DWI.The b values were chosen as 300,500,800 and 1 000 s/mm2 ,and the corresponding apparent diffusion coefficient (ADC)values and the signal intensity (SI)were respectively measured.Results The ADC values and SI of benign and malignant SPNs were gradually reduced with increasing b value.The ADC value between benign and malignant SPNs was statistically significant with b value of 500 s/mm2 (P 500 =0.03 <0.05 ),meanwhile the SI was statistically significant with b values from 300 to 1000 s/mm2 (P 300 <0.001,P 500 =0.03 <0.05,P 800 =0.01 <0.05, P 1 000 =0.02<0.05).Conclusion Both SI and ADC value of DWI play important role in distinguishing benign and malignant SPNs, and the diagnostic efficiency of SI is superior to ADC value.
