Computed tomography (CT) cannot differentiate benign from malignant pulmonary lesion.Diffusion weighted magnetic resonance imaging(DW-MRI) can evaluate lung cancer using ADC which is inveresly correlated to tissue cellularity.
Objective: To evaluate the role of measurement of ADC in the differentiation between benign and malignant pulmonary lesions.
Patients&Methods: 42 patients with pulmonary masses were included in this study. They underwent diffusion weighted MRI. ADC value measurement and histopathological diagnosis were done for each lesion.
Results:
The mean age for the studied patients was 57.85± 10.6 years with male predominance (34 patients). On histopathological bases they were subdivided into benign (12 patients) and malignant (30patients).The mean ADCx10-3 for the malignant lesions(0.92±0.15) was significantly(p<0.001) lower than benign lesions(1.55 ± 0.15) as shown in Figure1

In malignant tumors, ADC value for small cell lung cancer was significantly(p<0.05) lower than non small cell lung cancer . Using ADC value of 1.10x10-3 mm2/s as the cut-off threshold for the differentiation between benign and malignant lesions the sensitivity, specificity, PPV and NPP were 96.7% and 83.3%, 93.5% and 90.9% respectively.
Conclusion:
Diffusion weighted MRI with measurement of ADC value is very helpful in the differentiation between malignant and benign pulmonary lesions