Combined FDG PET/MRI versus Standard-of-Care Imaging in the Evaluation of Cardiac Sarcoidosis

Constantin A Marschner; Faisal Aloufi; Matthew Aitken; Edward Cheung; Paaladinesh Thavendiranathan; Robert M Iwanochko; Meyer Balter; Yasbanoo Moayedi; Juan Duero Posada; Kate Hanneman

doi:10.1148/ryct.220292

Combined FDG PET/MRI versus Standard-of-Care Imaging in the Evaluation of Cardiac Sarcoidosis

Radiol Cardiothorac Imaging. 2023 Sep 28;5(5):e220292. doi: 10.1148/ryct.220292. eCollection 2023 Oct.

Affiliation

¹ From 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.).

Abstract

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.

Keywords: 18F-FDG PET/CT; 18F-FDG PET/MRI; Cardiac MRI; Cardiac Sarcoidosis; SPECT Perfusion Imaging; Standard-of-Care Imaging.

Associated data

ClinicalTrials.gov/NCT03356756