Free-Breathing Radial 3D Fat-Suppressed T1-Weighted Gradient Echo Sequence for Pulmonary Nodule Detection in Patients Undergoing PET/CT Followed by Simultaneous PET/MR Examination

Hersh Chandarana¹, Laura Heacock¹, Rajan Rakheja¹, Linda DeMello¹, John Bonavita¹, Kai Tobias Block¹, Christian Geppert², Kent Friedman¹

Recently introduced integrated whole-body PET/MR systems may play an important role in oncologic evaluation. However, there are concerns regarding ability of MRI in detecting pulmonary nodules. 32 consecutive patients undergoing clinically indicated 18F-FDG-PET/CT immediately followed by PET/MR (Siemens Biograph mMR) were studied. MR imaging was performed simultaneously with PET acquisition using a free-breathing radial 3D fat-suppressed T1-weighted gradient echo sequence (Radial VIBE-RV). RV detected all FDG avid nodules greater than 0.7 cm in size but had lower sensitivity for small nodules and non-FDG avid nodules. This has important implications for oncologic imaging with PET/MR.