Abstract
The objective of the present study was to evaluate whether integrated 18F-FDG-PET/MRI can improve the diagnostic workup in patients with cardiac masses. Methods: Twenty patients were prospectively assessed using integrated cardiac 18F-FDG-PET/MRI: 16 patients with cardiac masses of unknown identity and four patients with cardiac sarcoma after surgical therapy. All scans were performed on an integrated 3-T PET/MR device (mMR Biograph, Siemens Healthcare, Erlangen, Germany). The MR protocol consisted of HASTE, cine and T2-weighted images as well as T1-weighted images before and after injection of gadobutrol. PET data acquisition was performed simultaneously to the MR scan after injection of 199±58 MBq 18F-FDG. Patients were prepared with a high-fat, low-carbohydrate diet in a period of 24 hours before the examination and 50 IU/kg of unfractionated heparin were administered intravenously 15 minutes prior the 18F-FDG injection. Results: Cardiac masses were diagnosed as follows: 3 x metastases, 1 x direct tumor infiltration via pulmonary vein, 2 x local relapse of primary sarcoma after surgery, 1 Burkitt’s lymphoma, 2 x scar/patch tissue after surgery of primary sarcoma, 4 x myxoma, 1 x fibroelastoma, 3 x caseous calcification of mitral annulus (CCMA), 3 x thrombus. SUVmax in malignant lesions was significantly higher than in non-malignant cases (13.2±6.2 vs. 2.3±1.2, P = 0.0004). Using a threshold of ≥ 5.2, SUVmax was found to yield 100% sensitivity and 92% specificity for the differentiation between malignant and non-malignant cases. T2-weighted hyperintensity and contrast-enhancement both yielded 100% sensitivity, but a weak specificity of 54% and 46%, respectively. Morphologic tumor features as assessed by cine MRI yielded 86% sensitivity and 92% specificity. Consent reading using all available MR features yielded 100% sensitivity and 92% specificity. A Boolean ‘AND’ combination of SUVmax ≥ 5.2 with consent MRI reading improved sensitivity and specificity to 100%. Conclusion: In selected patients, 18F-FDG-PET/MRI can improve the noninvasive diagnosis and follow-up of cardiac masses.
- Cardiology (clinical)
- Oncology: General
- PET/MRI
- PET/MRI
- cardiac PET
- cardiac malignancy
- cardiac masses
- cardiac tumors
- Copyright © 2014 by the Society of Nuclear Medicine and Molecular Imaging, Inc.