PET/MRI in Lung Cancer

Introduction Imaging plays an important role in the diagnosis and management of lung cancer, which is the leading cause of cancer-related death in the world. Radiography is often the initial modality of diagnosis, but detection depends on the size and density of nodules. The sensitivity of detection may be improved by using the dual-energy subtraction technique, which generates a soft tissue reconstruction that is free of overlapping chest wall and bony structures, or by using tomosynthesis. Computed tomography (CT) has become the established modality for the screening, diagnosis, and staging of lung cancers. Radiation and the use of potentially nephrotoxic contrast media are the risk factors associated with it. Magnetic resonance imaging (MRI) does not involve radiation, but its use in lung cancer is limited by intrinsic low proton spin density, magnetic field inhomogeneities, and motion artifacts from cardiac and respiratory motion. However, novel sequences show potential in the evaluation of lung cancer. Positron emission tomography (PET) with 18-fluorodeoxyglucose (FDG-PET) is useful in determining the metabolic activity of the lung tumor. False-negative results are seen in small tumors and in bronchoalevolar carcinoma, whereas falsepositive findings are seen in cases of infection or inflammation. The hybrid imaging modality of PET/CT is now the standard of care in the staging of lung cancers, combining the morphologic information of CT with the metabolic information of PET. PET/MRI is a novel hybrid imaging technology that involves the fusion of 2 powerful imaging modalities: PET and MRI. MRI provides tissue characterization capabilities