Characterisation of solitary pulmonary lesions combining visual perfusion and quantitative diffusion MR imaging.

OBJECTIVE

To evaluate the diagnostic accuracy of dynamic contrast-enhanced (DCE) magnetic resonance (MR) and diffusion-weighted imaging (DWI) sequences for defining benignity or malignancy of solitary pulmonary lesions (SPL).

METHODS

First, 54 consecutive patients with SPL, clinically staged (CT and PET or integrated PET-CT) as N0M0, were included in this prospective study. An additional 3-Tesla MR examination including DCE and DWI was performed 1 day before the surgical procedure. Histopathology of the surgical specimen served as the standard of reference. Subsequently, this functional method of SPL characterisation was validated with a second cohort of 54 patients.

RESULTS

In the feasibility group, 11 benign and 43 malignant SPL were included. Using the combination of conventional MR sequences with visual interpretation of DCE-MR curves resulted in a sensitivity, specificity and accuracy of 100%, 55% and 91%, respectively. These results can be improved by DWI (with a cut-off value of 1.52 × 10(-3) mm(2)/s for ADChigh) leading to a sensitivity, specificity and accuracy of 98%, 82% and 94%, respectively. In the validation group these results were confirmed.

CONCLUSION

Visual DCE-MR-based curve interpretation can be used for initial differentiation of benign from malignant SPL, while additional quantitative DWI-based interpretation can further improve the specificity.

KEY POINTS

• Magnetic resonance imaging is increasingly being used to help differentiate lung lesions. • Solitary pulmonary lesions (SPL) are accurately characterised by combining DCE-MRI and DWI. • Visual DCE-MRI assessment facilitates the diagnostic throughput in patients with SPL. • DWI provides additional information in inconclusive DCE-MRI (type B pattern).