Related Experiment Video
Updated: Jul 8, 2025
High-Resolution Cardiac Positron Emission Tomography/Computed Tomography for Small Animals
Published on: December 16, 2022
Combined FDG PET/MRI versus Standard-of-Care Imaging in the Evaluation of Cardiac Sarcoidosis
Constantin A Marschner1, Faisal Aloufi1, Matthew Aitken1
1From the Department of Medical Imaging (C.A.M., F.A., M.A., E.C., P.T., K.H.) and Division of Cardiology (P.T., M.R.I., Y.M., J.D.P.), Peter Munk Cardiac Centre, Toronto General Hospital, University Health Network, University of Toronto, 585 University Ave, 1 PMB-298, Toronto, ON, Canada M5G 2N2; Toronto General Hospital Research Institute, University Health Network, University of Toronto, Toronto, Canada (P.T., K.H.); Division of Molecular Imaging, Toronto General Hospital, University Health Network, University of Toronto, Toronto, Canada (M.R.I.); and Division of Respiratory Medicine, Sinai Health System, University of Toronto, Toronto, Canada (M.B.).
Purpose:
To compare combined cardiac fluorine 18 (18F) fluorodeoxyglucose (FDG) PET/MRI with standard-of-care evaluation using cardiac MRI, 18F-FDG PET/CT, and SPECT perfusion imaging in suspected cardiac sarcoidosis (CS) with respect to radiation dose, imaging duration, and diagnostic test performance.
Materials And Methods:
Consecutive patients with suspected CS undergoing clinical evaluation with cardiac 18F-FDG PET/CT and gated rest technetium 99m sestamibi SPECT perfusion imaging were prospectively recruited between November 2017 and May 2021 for parallel assessment with combined cardiac 18F-FDG PET/MRI on the same day (ClinicalTrials.gov identifier, NCT03356756). Total effective radiation dose and imaging duration were compared between approaches (combined cardiac PET/MRI vs separate cardiac MRI, PET/CT, and SPECT). MRI findings were initially interpreted without PET data, and then PET and late gadolinium enhancement images were fused and interpreted together. Final diagnosis of CS was established using Japanese Ministry of Health and Welfare guidelines.
Results:
Forty participants (mean age, 54 years ± 14 [SD]; 26 [65%] male participants) were included, 14 (35%) with a final diagnosis of CS. Compared with separate cardiac MRI, PET/CT, and SPECT perfusion imaging, combined cardiac PET/MRI had 52% lower total radiation dose (8.0 mSv ± 1.2 vs 16.8 mSv ± 1.6, P < .001) and 43% lower total imaging duration (122 minutes ± 15 vs 214 minutes ± 26, P < .001). Combined PET/MRI had the highest area under the curve for diagnosis of CS (0.84) with 96% specificity and 71% sensitivity for colocalized FDG uptake and late gadolinium enhancement in a pattern typical for CS.
Conclusion:
In the evaluation of suspected CS, combined cardiac 18F-FDG PET/MRI had a lower radiation dose, shorter imaging duration, and higher diagnostic performance compared with standard-of-care imaging.Clinical trial registration no. NCT03356756Keywords: Cardiac Sarcoidosis, 18F-FDG PET/MRI, 18F-FDG PET/CT, SPECT Perfusion Imaging, Cardiac MRI, Standard-of-Care Imaging Supplemental material is available for this article. © RSNA, 2023.
Insights
Combined cardiac 18F-FDG PET/MRI significantly reduces radiation dose and imaging time for suspected cardiac sarcoidosis (CS). This advanced imaging offers superior diagnostic performance compared to standard-of-care methods.
Area of Science:
- Cardiovascular Imaging
- Nuclear Medicine
- Radiology
Background:
- Cardiac sarcoidosis (CS) diagnosis is challenging, often requiring multiple imaging modalities.
- Standard-of-care involves cardiac MRI, 18F-FDG PET/CT, and SPECT perfusion imaging, each with limitations.
- Evaluating CS necessitates assessing radiation dose, duration, and diagnostic accuracy.
Purpose of the Study:
- To compare combined cardiac 18F-FDG PET/MRI with standard-of-care imaging for suspected CS.
- To evaluate differences in radiation dose, imaging duration, and diagnostic performance.
- To determine the efficacy of integrated PET/MRI in CS diagnosis.
Main Methods:
- Prospective recruitment of patients with suspected CS.
- Parallel assessment using combined cardiac 18F-FDG PET/MRI and standard-of-care (cardiac MRI, 18F-FDG PET/CT, SPECT).
- Comparison of total effective radiation dose and imaging duration; final diagnosis based on established guidelines.
Main Results:
- Combined cardiac PET/MRI demonstrated a 52% lower radiation dose and 43% shorter imaging duration.
- The integrated PET/MRI approach achieved an AUC of 0.84 for CS diagnosis.
- High specificity (96%) and sensitivity (71%) were observed for colocalized findings on PET/MRI.
Conclusions:
- Combined cardiac 18F-FDG PET/MRI is a more efficient and effective imaging strategy for suspected CS.
- This approach offers reduced radiation exposure and shorter patient time compared to standard methods.
- Integrated PET/MRI enhances diagnostic performance in evaluating cardiac sarcoidosis.
Related Concept Videos
01:25Imaging Studies II: Positron Emission Tomography and Scintigraphy
Fundamental Principles of PET
01:13Radiological Investigation III: Pulmonary Angiogram and PET Scan
Pulmonary Angiogram
A Pulmonary Angiogram is an invasive procedure involving injecting a contrast medium through a catheter threaded into the pulmonary artery or the right side of the heart to visualize the pulmonary vasculature. Computed Tomography (CT) scans have mainly replaced this...
01:29Positron Emission Tomography
One of the main requirements of a PET scan is a positron-emitting radioisotope, which is produced in a cyclotron and then attached to a substance used by the part of the body...