Related Experiment Video
Updated: Sep 4, 2025
Whole-body PET/MRI of Pediatric Patients: The Details That Matter
Published on: December 19, 2017
Optimized Whole-Body PET MRI Sequence Workflow in Pediatric Hodgkin Lymphoma Patients
Thomas W Georgi1, Dietrich Stoevesandt2, Lars Kurch3
1Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany; thomas.georgi@medizin.uni-leipzig.de.
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.
Insights
Optimized MRI sequences improve whole-body PET/MRI for Hodgkin lymphoma. T2w transverse sequences with fat saturation offer the highest detection rates for nodal, skeletal, and lung lesions, enhancing diagnostic accuracy.
Area of Science:
- Oncology
- Radiology
- Medical Imaging
Background:
- 18F-FDG PET/MRI offers metabolic and soft-tissue contrast advantages for Hodgkin lymphoma diagnosis, avoiding CT radiation.
- Extended scan times in PET/MRI, particularly for pediatric patients requiring anesthesia, necessitate workflow optimization.
- Efficient selection of whole-body MRI sequences is crucial for improving the PET/MRI procedure.
Purpose of the Study:
- To evaluate the effectiveness of different whole-body MRI sequences for detecting lesions in Hodgkin lymphoma patients undergoing PET/MRI.
- To identify the optimal MRI sequences for enhancing diagnostic accuracy and efficiency in pediatric and adult Hodgkin lymphoma imaging.
Main Methods:
- Analysis of initial PET/MRI scans from 84 patients in the EuroNet-PHL-C2 study across 13 international centers.
- Assessment of lesion detection rates for lymph nodes, spleen, skeleton, and lungs across various MRI sequences.
- Calculation of detection rates by comparing visible, assignable, and measurable lesions to the total number of lesions per sequence.
Main Results:
- T2w transverse sequences with fat saturation (fs) demonstrated the highest detection rates: 95% for nodal, 62% for splenic, 94% for skeletal, and 83% for lung lesions.
- T2w transverse sequences without fs showed lower detection rates (86%, 49%, 16%, 59% respectively).
- Contrast-enhanced sequences with fs yielded lower detection rates (74%, 35%, 57%, 55% respectively), with no evidence supporting contrast agent use.
Conclusions:
- T2w transverse sequences with fat saturation are highly effective for accurate whole-body PET/MRI in lymphoma patients.
- These sequences provide superior lesion detection compared to other evaluated MRI techniques.
- Contrast agents are not recommended for routine use in this setting, simplifying the imaging protocol.
