Magnetic Resonance Imaging of Part-solid Nodules: A Pilot Study

Area of Science:

• Pulmonary imaging
• Radiology
• Oncology

Background:

• Part-solid pulmonary nodules require accurate characterization to distinguish benign from malignant lesions.
• Conventional imaging techniques like CT and PET/CT have limitations in differentiating nodule types.
• Magnetic resonance imaging (MRI) offers potential for non-invasive assessment of pulmonary nodules.

Purpose of the Study:

• To evaluate if MRI characteristics can differentiate benign from malignant part-solid pulmonary nodules.
• To assess the ability of MRI to predict the aggressiveness of malignant nodules.
• To compare MRI-derived parameters with conventional imaging metrics (CT, PET/CT).

Main Methods:

• A pilot study involving 28 participants with 32 biopsy-proven lesions.
• 3-Tesla (3T) unenhanced pulmonary MRI was performed.
• Quantitative parameters including apparent diffusion coefficient (ADC) and T2* values were calculated.
• MRI parameters were correlated with histopathology, SUVmax, and Hounsfield units (HU).

Main Results:

• Apparent diffusion coefficient (ADC) values significantly correlated with malignancy (P<0.05).
• An ADC threshold of ≥1.28 μm/ms predicted malignancy with 83.3% sensitivity.
• ADC and T2* values correlated with specific adenocarcinoma subtypes (P<0.05).
• T1 and T2 values correlated with Hounsfield unit measurements of the nodule and its solid components.

Conclusions:

• Quantitative ADC values from 3T MRI show promise in discriminating benign from malignant part-solid pulmonary nodules.
• ADC and T2* values are associated with adenocarcinoma subtypes.
• MRI parameters demonstrated correlations with CT-based measurements (HU), but not with SUVmax.