Diffusion-Weighted MRI Can Characterize Pulmonary Lesions

Magnetic resonance imaging is comparable to fluorine 18 fluorodeoxyglucose PET/CT in determining if pulmonary lesions are malignant or benign, according to a study published in the journal Radiology.

Researchers from Brazil, the United States, and the United Kingdom performed a literature meta-analysis to compare how the diagnostic performance of fluorine 18 fluorodeoxyglucose PET/CT and diffusion-weighted (DW) MRI differed in determining malignant and benign pulmonary nodules and masses.

The researchers focused on studies that where DW MRI and PET/CT were performed in the entire study population:

• Lesion-to–spinal cord signal intensity ratio and apparent diffusion coefficient were evaluated for DW MRI

• Maximum standard uptake value was evaluated for PET/CT

The pooled sensitivities, specificities, diagnostic odds ratios, and areas under the receiver operating characteristic curve (AUCs) for PET/CT and DW MRI were determined.

The results showed that the 37 studies that met the inclusion criteria and a total of 4,224 participants and 4,463 lesions; 3,090 of the lesions were malignant (69.2%).

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The primary analysis of the 6 joint DW MRI and PET/CT studies showed that DW MRI had a pooled sensitivity of 83% and specificity of 91%, compared with a pooled sensitivity of 78% and specificity of 81% for PET/CT. DW MRI yielded an AUC of 0.93  versus 0.86 for PET/CT. The diagnostic odds ratio of DW MRI (50) was superior to that of PET/CT (15).

The researchers concluded that the diagnostic performance of diffusion-weighted MRI was comparable or superior to that of fluorine 18 fluorodeoxyglucose PET/CT when differentiating between malignant and benign pulmonary lesions.