Practical guide for implementing hybrid PET/MR clinical service: lessons learned from our experience

Abstract

Positron emission tomography (PET) and magnetic resonance imaging, until recently, have been performed on separate PET and MR systems with varying temporal delay between the two acquisitions. The interpretation of these two separately acquired studies requires cognitive fusion by radiologists/nuclear medicine physicians or dedicated and challenging post-processing. Recent advances in hardware and software with introduction of hybrid PET/MR systems have made it possible to acquire the PET and MR images simultaneously or near simultaneously. This review article serves as a road-map for clinical implementation of hybrid PET/MR systems and briefly discusses hardware systems, the personnel needs, safety and quality issues, and reimbursement topics based on experience at NYU Langone Medical Center and Cleveland Clinic.

Application of PET/MRI in Gynecologic Malignancies

“…The primary radiotracer in the oncologic PET/MRI of the female pelvis is FDG. Metabolic activity can be influenced by several factors, including diet, extreme physical activity, trauma, medications, infection/inflammation, and environmental temperature [45]. Therefore, a consideration of these factors when performing a PET/MRI may be helpful to ensuring the quality and reliability of results.…”

“…[44,45] Separate PET/CT and MR systems Shared transport bed, compatible with both scanners, improves anatomical correspondence between PET and MRI Relatively low cost Access to image data from three modalities (including CT-based attenuation correction of PET data) Flexibility to use the systems independently Risk of misalignment due to patient motion or bowel motility Longer examination time compared to sequential and integrated systems Sequential [46] PET and MR bores positioned in a serial fashion MR images acquired immediately after PET, within the same examination Reduced dose of ionizing radiation by not conducting a CT Reduced total examination time Lower likelihood of image misalignment compared to tri-modality systems due to the shorter time between scans Special shielding and additional space requirements due to systems proximity Lack of conventional CT-based attenuation correction Potential impact on the quality of reconstructed PET images due to MR-based attenuation correction Integrated [47] Simultaneously acquiring PET and MR images by incorporating PET into the MR bore True simultaneous PET and MRI acquisitions Improved image alignment between modalities Reduced dose of ionizing radiation Reduced total examination time High purchase price compared to sequential systems…”

Joint EANM/SIOPE/RAPNO practice guidelines/SNMMI procedure standards for imaging of paediatric gliomas using PET with radiolabelled amino acids and [18F]FDG: version 1.0

“…Considering that a recent MRI should be always available to correctly interpret the PET findings, a non-diagnostic and low-dose CT without contrast should be recommended. In the case of a PET/MRI study, along minimal requirements related to the PET component, paediatric patients necessitate an additional screening checklist for relevant contraindication to MRI including metallic implants and claustrophobia [ 49 ]. Moreover, given the longer acquisition time generally required for PET/MRI studies, a preliminary assessment for patient sedation or general anaesthesia must be performed.…”

On the potential for RF heating in MRI to affect metabolic rates and 18FDG signal in PET/MR: simulations of long‐duration, maximum normal mode heating

“…The advantages of simultaneously acquiring the complimentary information available in MRI and PET have led to a growth in the number of systems and applications for PET/ MR. [1][2][3][4][5][6][7][8] MRI provides anatomical information with high temporal and spatial resolution as well as a variety of other physiologic information without the need for ionizing radiation. Using a wide range of radiopharmaceuticals, PET can rapidly locate regions of abnormal function with high specificity.…”