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Updated: Jun 15, 2025
Radiotracer Administration for High Temporal Resolution Positron Emission Tomography of the Human Brain: Application to FDG-fPET
Published on: October 22, 2019
Time-synchronized 2-deoxy-2-[18F]fluoro-D-glucose PET/MRI with MR-active trigger and Bayesian penalized likelihood
Miho Tachibana1, Munenobu Nogami2, Junko Inoue Inukai3
1Department of Radiology, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe, Hyogo 650-0017, Japan; Kakogawa City Hospital, 439 Hommachi Kakogawa-cho, Kakogawa, Hyogo 675-8611, Japan.
Purpose:
Minimal misregistration of fused PET and MRI images can be achieved with simultaneous positron emission tomography/magnetic resonance imaging (PET/MRI). However, the acquisition of multiple MRI sequences during a single PET emission scan may impair fusion precision of each sequence. This study evaluated the diagnostic utility of time-synchronized PET/MRI using an MR active trigger and a Bayesian penalized likelihood reconstruction algorithm (BPL) to assess the locoregional extension of endometrial cancer.
Methods:
Fifty-five patients with endometrial cancer who underwent pelvic 2-deoxy-2-[18F]fluoro-D-glucose PET/MRI were retrospectively evaluated. The PET emission time for the BPL reconstruction was determined by the MR active trigger of each MR sequence. The concordance rates of image interpretation with pathological T-staging, diagnostic performance for deep myometrial invasion (MI), and diagnostic confidence levels were evaluated by two readers and compared between time-synchronized, overlapping (conventional and simultaneous, but not time-synchronized), and sequential (not simultaneous) PET/MRI and MRI with diffusion-weighted imaging. Misregistration of the PET/MRI-fused images was determined by evaluating the differences in bladder dimensions.
Results:
The T classification by time-synchronized PET/MRI was the most concordant with the pathological T classification for the two readers. Time-synchronized PET/MRI had a significantly higher diagnostic performance for deep MI and higher confidence level scores than overlapping PET/MRI for the novice reader (p = 0.033 and p = 0.038, respectively). The differences in bladder dimension on sequential PET/MRI were significantly larger than those on overlapping and time-synchronized PET/MRI (p <0.001).
Conclusion:
Time-synchronized PET/MRI is superior to conventional PET/MRI for assessing the locoregional extension of endometrial cancer.
Insights
Time-synchronized PET/MRI improves endometrial cancer staging accuracy. This method offers superior diagnostic performance and confidence compared to conventional PET/MRI techniques.
Area of Science:
- Oncology
- Radiology
- Medical Imaging
Background:
- Simultaneous positron emission tomography/magnetic resonance imaging (PET/MRI) offers potential for minimal misregistration.
- Acquiring multiple MRI sequences during a PET scan can compromise fusion precision.
- Assessing endometrial cancer requires precise imaging for locoregional extension evaluation.
Purpose of the Study:
- To evaluate the diagnostic utility of time-synchronized PET/MRI for endometrial cancer staging.
- To compare time-synchronized PET/MRI with conventional PET/MRI techniques.
- To assess the impact of MR active trigger and Bayesian penalized likelihood (BPL) reconstruction on image fusion.
Main Methods:
- Retrospective evaluation of 55 endometrial cancer patients undergoing 2-deoxy-2-[18F]fluoro-D-glucose PET/MRI.
- PET emission time determined by MR active trigger for BPL reconstruction.
- Comparison of image interpretation concordance, diagnostic performance for deep myometrial invasion (MI), and confidence levels between different PET/MRI synchronization methods and MRI with diffusion-weighted imaging.
Main Results:
- Time-synchronized PET/MRI demonstrated the highest concordance with pathological T-staging.
- Significantly improved diagnostic performance for deep MI and higher confidence scores were observed with time-synchronized PET/MRI compared to overlapping PET/MRI for a novice reader.
- Sequential PET/MRI showed significantly larger differences in bladder dimensions, indicating greater misregistration.
Conclusions:
- Time-synchronized PET/MRI is superior to conventional PET/MRI for assessing endometrial cancer locoregional extension.
- The use of an MR active trigger enhances the precision of PET/MRI fusion.
- This technique improves diagnostic accuracy and confidence in staging endometrial cancer.
