Related Experiment Video
Updated: Apr 9, 2026
High-Resolution Cardiac Positron Emission Tomography/Computed Tomography for Small Animals
Published on: December 16, 2022
MR-based attenuation correction for cardiac FDG PET on a hybrid PET/MRI scanner: comparison with standard CT
Jan Vontobel1, Riccardo Liga, Mathias Possner
1Department of Nuclear Medicine, University Hospital Zurich, Ramistrasse 100, 8091, Zurich, Switzerland.
Purpose:
The aim of this study was to evaluate the feasibility of attenuation correction (AC) for cardiac (18)F-labelled fluorodeoxyglucose (FDG) positron emission tomography (PET) using MR-based attenuation maps.
Methods:
We included 23 patients with no known cardiac history undergoing whole-body FDG PET/CT imaging for oncological indications on a PET/CT scanner using time-of-flight (TOF) and subsequent whole-body PET/MR imaging on an investigational hybrid PET/MRI scanner. Data sets from PET/MRI (with and without TOF) were reconstructed using MR AC and semi-quantitative segmental (20-segment model) myocardial tracer uptake (per cent of maximum) and compared to PET/CT which was reconstructed using CT AC and served as standard of reference.
Results:
Excellent correlations were found for regional uptake values between PET/CT and PET/MRI with TOF (n = 460 segments in 23 patients; r = 0.913; p < 0.0001) with narrow Bland-Altman limits of agreement (-8.5 to +12.6 %). Correlation coefficients were slightly lower between PET/CT and PET/MRI without TOF (n = 460 segments in 23 patients; r = 0.851; p < 0.0001) with broader Bland-Altman limits of agreement (-12.5 to +15.0 %). PET/MRI with and without TOF showed minimal underestimation of tracer uptake (-2.08 and -1.29 %, respectively), compared to PET/CT.
Conclusion:
Relative myocardial FDG uptake obtained from MR-based attenuation corrected FDG PET is highly comparable to standard CT-based attenuation corrected FDG PET, suggesting interchangeability of both AC techniques.
Insights
MR-based attenuation correction (AC) for cardiac (18)F-fluorodeoxyglucose (FDG) PET is feasible and comparable to CT-based AC. This suggests that MR-based AC can be used interchangeably with CT-based AC for myocardial FDG PET imaging.
Area of Science:
- Nuclear Medicine
- Radiology
- Medical Imaging
Background:
- Cardiac positron emission tomography (PET) is crucial for assessing myocardial viability and function.
- Accurate attenuation correction (AC) is essential for quantitative analysis in PET imaging.
- Computed tomography (CT) based AC is the current standard for PET/CT scanners.
Purpose of the Study:
- To evaluate the feasibility of using magnetic resonance (MR)-based attenuation maps for AC in cardiac (18)F-fluorodeoxyglucose (FDG) PET.
- To compare the accuracy of MR-based AC with the standard CT-based AC for myocardial FDG uptake measurements.
Main Methods:
- 23 patients underwent whole-body FDG PET/CT and PET/MRI scans.
- Cardiac FDG uptake was quantified using a 20-segment model on both PET/CT (CT AC) and PET/MRI (MR AC) datasets.
- PET/MRI data were reconstructed with and without time-of-flight (TOF) for comparison.
Main Results:
- Excellent correlation (r=0.913) was observed between PET/CT and TOF PET/MRI, with narrow Bland-Altman limits of agreement (-8.5 to +12.6%).
- Slightly lower correlation (r=0.851) was found between PET/CT and non-TOF PET/MRI, with broader limits (-12.5 to +15.0%).
- PET/MRI demonstrated minimal underestimation of tracer uptake compared to PET/CT.
Conclusions:
- MR-based AC for cardiac FDG PET provides results highly comparable to CT-based AC.
- The findings suggest interchangeability between MR-based and CT-based AC techniques for myocardial FDG PET.
- This supports the potential integration of MR-based AC in hybrid PET/MRI systems for cardiac imaging.
