Room: Exhibit Hall | Forum 5
Purpose: The purpose of this study is to investigate the technique challenges in developing whole body (WB)PET/MR imaging.
Methods: Total 10 subjects including healthy volunteers and clinical patients underwent the whole-body (head to toe) PET/MR hybrid imaging on a GE 3.0T PET/MR scanner. The PET/MR coil suite, including central molecular imaging array, head neck unit, upper anterior array and lower anterior array coils, were used for the WB-PET/MR scanning. Healthy volunteers were recruited to optimize imaging workflow in terms of patient position, coil selection & configuration, MR sequences (T1, T2, STIR, DWI) optimization, and image binding and pasting. Four patients after PET/CT exams were performed a WB-PET/MR scan within 30 minutes subsequently to study the MRAC issues, validate standardized uptake value (SUV) accuracy, and explore SUV correlationship between PET/CT and PET/MR. Finally, we applied the optimized protocols to clinical service on indicated clinical patients.
Results: Position the patient and coils setup are very important for WB-PET/MR imaging. The coil selection and coil mode configurations depending on the patient position not only affect the MRI image quality but also influence the PET image quantification. Current attenuation correction of PET/MRI are based on MR images, atlas for head and a four-class continued fat and water density method for other body parts. It is important to position the boundaries in the correct area of interest to obtain optimal attenuation correction. There is strong linear relationship between the SUVs derived from PET/CT and PET/MR. Several WB-PET/MR clinical applications and reproducibility have been demonstrated in this study.
Conclusion: Patient position, coil configuration, MR-based attenuation correction and image reconstruction are key factors to consider for improvement of PET/MR whole body image quality and PET/MR multiparametric quantitation. Our clinical studies have shown promising results in clinical applications, such as plexiform neurofibromatosis Type 1 and multiple myeloma.