Optimized Whole-Body PET MRI Sequence Workflow in Pediatric Hodgkin Lymphoma Patients

J Nucl Med. 2023 Jan;64(1):96-101. doi: 10.2967/jnumed.122.264112. Epub 2022 Jul 14.

Abstract

18F-FDG PET/MRI might be the diagnostic method of choice for Hodgkin lymphoma patients, as it combines significant metabolic information from PET with excellent soft-tissue contrast from MRI and avoids radiation exposure from CT. However, a major issue is longer examination times than for PET/CT, especially for younger children needing anesthesia. Thus, a targeted selection of suitable whole-body MRI sequences is important to optimize the PET/MRI workflow. Methods: The initial PET/MRI scans of 84 EuroNet-PHL-C2 study patients from 13 international PET centers were evaluated. In each available MRI sequence, 5 PET-positive lymph nodes were assessed. If extranodal involvement occurred, 2 splenic lesions, 2 skeletal lesions, and 2 lung lesions were also assessed. A detection rate was calculated dividing the number of visible, anatomically assignable, and measurable lesions in the respective MRI sequence by the total number of lesions. Results: Relaxation time-weighted (T2w) transverse sequences with fat saturation (fs) yielded the best result, with detection rates of 95% for nodal lesions, 62% for splenic lesions, 94% for skeletal lesions, and 83% for lung lesions, followed by T2w transverse sequences without fs (86%, 49%, 16%, and 59%, respectively) and longitudinal relaxation time-weighted contrast-enhanced transverse sequences with fs (74%, 35%, 57%, and 55%, respectively). Conclusion: T2w transverse sequences with fs yielded the highest detection rates and are well suited for accurate whole-body PET/MRI in lymphoma patients. There is no evidence to recommend the use of contrast agents.

Keywords: Hodgkin lymphoma; MRI sequences; PET/MRI; whole-body imaging.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bone Diseases*
  • Child
  • Diffusion Magnetic Resonance Imaging / methods
  • Fluorodeoxyglucose F18
  • Hodgkin Disease* / diagnostic imaging
  • Hodgkin Disease* / pathology
  • Humans
  • Magnetic Resonance Imaging / methods
  • Neoplasm Staging
  • Positron Emission Tomography Computed Tomography
  • Positron-Emission Tomography / methods
  • Radiopharmaceuticals
  • Whole Body Imaging / methods
  • Workflow

Substances

  • Fluorodeoxyglucose F18
  • Radiopharmaceuticals