Diagnostic Performance of DWI With Multiple Parameters for Assessment and Characterization of Pulmonary Lesions: A Meta-Analysis

OBJECTIVE: The objective of our study was to evaluate the diagnostic performance of DWI using a 5-point rank scale, lesion-to-spinal cord signal intensity ratio, which we refer to as "LSR," and apparent diffusion coefficient (ADC) for the characterization of pulmonary lesions. MATERIALS AND METHODS: After a literature search in several databases, two investigators independently selected studies, assessed methodologic quality, and extracted data. On a per-lesion basis, we pooled and compared the three parameters for malignant and benign lesions. Also, we determined pooled sensitivity and specificity with individual 95% CIs. RESULTS: In total, 31 articles involving 2368 lesions were included. The mean scores of malignant and benign lesions on the 5-point scale were 3.83 (95% CI, 3.71-3.96) and 2.36 (95% CI, 2.18-2.54), respectively. The mean LSRs of malignant and benign lesions were 1.15 (95% CI, 1.07-1.24) and 0.71 (95% CI, 0.62-0.79). The mean ADC values of malignant and benign lesions were 1.23 (95% CI, 1.21-1.24) and 1.72 (95% CI, 1.68-1.77). All three parameters differed significantly between malignant and benign lesions (p < 0.05). On the basis of these parameters, the pooled sensitivity and specificity were 0.88 (95% CI, 0.84-0.91) and 0.75 (95% CI, 0.68-0.80) for the 5-point scale, 0.80 (95% CI, 0.75-0.85) and 0.85 (95% CI, 0.76-0.92) for LSR, and 0.84 (95% CI, 0.82-0.86) and 0.84 (95% CI, 0.81-0.87) for ADC. CONCLUSION: Three DWI parameters-a visual parameter (score on a 5-point scale), semiquantitative parameter (LSR), and quantitative parameter (ADC)-can help to distinguish malignant from benign pulmonary lesions.